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7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 1108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 1
Fire resistance assessment of timber structures
Basic design methods
Worked examples
FRANGI Andrea
Member of CENTC250SC5 and HGF
ETH Zurich
Institute of Structural Engineering
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 2108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 2
London 9 storeys (UK)
Berlin 7 storeys(Germany)
Vaumlxjouml 8 storeys
(Sweden)
Bolzano 7 storeys (Italy)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 3108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 3
What is Eurocode 5
Eurocode 5 (EN 1995) provides rules for thedesign of timber structures
EN 1995-1-2 is the Fire Part of Eurocode 5The two other parts of Eurocode 5 areEN 1995-1-1 Common rules and rules for buildings
EN 1995-2 Bridges
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 4108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 4
EN 1995-1-2 deals with passive methods
of fire protection
EN 1995-1-2 gives design rules
for the verif ication of the
bull load-bearing function
bull separation function
Scope of EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 5108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 5
Insulation IIntegrity ELoad-bearing R
Passive methods of fire protection
Main objective limitation of the spread of f ire by guaranteeing
the load-carrying capacity of the structure
(Requirement on Mechanical Resistance R)
the separating function of walls and floors(Requirement on Insulation I and Integrity E)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 6108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 6
Load-bearing
elements without
separating
function
Non-load-bearing
elements wi th
separating
function
Load-bearing
elements with
separating
function
Fire
exposure
On all sides
On only one
side
On only one
side
Columns beams Walls Floors
Basic fire requirements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 7108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 8108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 10108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 11108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 15108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 17108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 2
London 9 storeys (UK)
Berlin 7 storeys(Germany)
Vaumlxjouml 8 storeys
(Sweden)
Bolzano 7 storeys (Italy)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 3108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 3
What is Eurocode 5
Eurocode 5 (EN 1995) provides rules for thedesign of timber structures
EN 1995-1-2 is the Fire Part of Eurocode 5The two other parts of Eurocode 5 areEN 1995-1-1 Common rules and rules for buildings
EN 1995-2 Bridges
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 4108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 4
EN 1995-1-2 deals with passive methods
of fire protection
EN 1995-1-2 gives design rules
for the verif ication of the
bull load-bearing function
bull separation function
Scope of EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 5
Insulation IIntegrity ELoad-bearing R
Passive methods of fire protection
Main objective limitation of the spread of f ire by guaranteeing
the load-carrying capacity of the structure
(Requirement on Mechanical Resistance R)
the separating function of walls and floors(Requirement on Insulation I and Integrity E)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 6
Load-bearing
elements without
separating
function
Non-load-bearing
elements wi th
separating
function
Load-bearing
elements with
separating
function
Fire
exposure
On all sides
On only one
side
On only one
side
Columns beams Walls Floors
Basic fire requirements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 3
What is Eurocode 5
Eurocode 5 (EN 1995) provides rules for thedesign of timber structures
EN 1995-1-2 is the Fire Part of Eurocode 5The two other parts of Eurocode 5 areEN 1995-1-1 Common rules and rules for buildings
EN 1995-2 Bridges
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 4
EN 1995-1-2 deals with passive methods
of fire protection
EN 1995-1-2 gives design rules
for the verif ication of the
bull load-bearing function
bull separation function
Scope of EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 5
Insulation IIntegrity ELoad-bearing R
Passive methods of fire protection
Main objective limitation of the spread of f ire by guaranteeing
the load-carrying capacity of the structure
(Requirement on Mechanical Resistance R)
the separating function of walls and floors(Requirement on Insulation I and Integrity E)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 6108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 6
Load-bearing
elements without
separating
function
Non-load-bearing
elements wi th
separating
function
Load-bearing
elements with
separating
function
Fire
exposure
On all sides
On only one
side
On only one
side
Columns beams Walls Floors
Basic fire requirements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 8108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 4
EN 1995-1-2 deals with passive methods
of fire protection
EN 1995-1-2 gives design rules
for the verif ication of the
bull load-bearing function
bull separation function
Scope of EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 5
Insulation IIntegrity ELoad-bearing R
Passive methods of fire protection
Main objective limitation of the spread of f ire by guaranteeing
the load-carrying capacity of the structure
(Requirement on Mechanical Resistance R)
the separating function of walls and floors(Requirement on Insulation I and Integrity E)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 6
Load-bearing
elements without
separating
function
Non-load-bearing
elements wi th
separating
function
Load-bearing
elements with
separating
function
Fire
exposure
On all sides
On only one
side
On only one
side
Columns beams Walls Floors
Basic fire requirements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 5
Insulation IIntegrity ELoad-bearing R
Passive methods of fire protection
Main objective limitation of the spread of f ire by guaranteeing
the load-carrying capacity of the structure
(Requirement on Mechanical Resistance R)
the separating function of walls and floors(Requirement on Insulation I and Integrity E)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 6
Load-bearing
elements without
separating
function
Non-load-bearing
elements wi th
separating
function
Load-bearing
elements with
separating
function
Fire
exposure
On all sides
On only one
side
On only one
side
Columns beams Walls Floors
Basic fire requirements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 8108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 6
Load-bearing
elements without
separating
function
Non-load-bearing
elements wi th
separating
function
Load-bearing
elements with
separating
function
Fire
exposure
On all sides
On only one
side
On only one
side
Columns beams Walls Floors
Basic fire requirements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 7108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 8108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 11108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 7
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 8108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 11108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 17108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 8108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 8
Pyrolysis thermal degradation of wood producing combustible
gases and accompanied by a loss in mass (starting from
about 250degC)
Charring rate
Ratio between charring depth
dchar and fire time t (in mmmin)
t
d char = β
minmmmin
mm
t
d char 8063
50=== β
Fire time
t = 63min
Residual
cross-section
Char layer
Timber behaviour in f ire
Material behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 10108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 11108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 15108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 17108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 9108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 9
depends on fire exposure
constant value for
ISO-fire exposure
depends on wood
species
spruce asymp 07 mmMin
small influence of
moisture content and
density of wood
Grundlagen ldquo Holz-Brandrdquo
Charring rate
Charring depth (mm)
Mean value fire tests
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 10108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 11108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 15108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 17108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 10
Char layer protects the residual cross-
section from high temperatures
Residual cross-
section
- ldquo coldldquo
- load-bearing
Source proHolz Austria
Temperature (degC)
Depth x (mm)
Material behaviour in f ire
Timber behaviour in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 12108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 13108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 14108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 11
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 12
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 13
0
100
200
300
400
500
600
700
800
900
0 10 20 30 40 50
Zeit [mi n]
T e m p e r a t u r [ deg C ]
Mode of action intumescent systems expand at a temperature of
about 200degC by a factor of 30 to 60 and form a compact insulating
layer
Time (min)
T e m p e r a t u r e ( deg C )
Material behaviour in f ire
Intumescent coating systems on steel members
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 14
ldquo Modern manmade
intumescent materials
applied to steel structuralelements are in essence an
attempt to replicate what
timber does naturallyrdquo
From paper ldquo Overview of design issues for tall
timber buildingsrdquo I Smith A Frangi
Structural Engineering International SEI 22008
Material behaviour in f ire
Intumescent coating
systems
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 15108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 15
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
timber elements
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 16108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 17108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 18108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 16
d c h a r 0
timber slab
One-dimensional charring charring rate 0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 17
dcharn
d
c h a r 0
dchar0
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 18
Notional charring notional charring rate n
d c h a r 0
dcharn
dchar0
Equivalent residual cross-section
Charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 19108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 19
Charring rates according to EN 1995-1-2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 20108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 21108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 22108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 20
Charring model for unprotected surfaces
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 21
Influence of fall off of cladding
Timber slab after 17 minutes ISO-fire exposure
Fall off of cladding
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 22
Charring rate not
constant
Increased charring rate
after failure of cladding
Timber element
Cladding
Protected timber surfaces
Unprotected
timber surfaces
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 23108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 23
Increased charring rate
after failure of cladding
the temperature in the furnace is
already at a high level when the
claddings fall off
no protective char layer exists
when the claddings fall off
Fire behaviour of initially protected surfaces
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 24108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 24
Charring model for init ially protected surfaces
Different charring phases
bull tch = time of start of charring
bull tf = failure time of cladding (fall off)
bull For wood-based panels and gypsum
plasterboards type A or H tch = tf
bull For gypsum plasterboards type F tch lt tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 25108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 25
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 26108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 26
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
t f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 27108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 27
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f
Charring model for init ially protected surfaces
For wood-based panels and gypsum plasterboards type A or H tch = tf
β β sdot= 2)2( a phase
β β =)2( b phase
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 28108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 28
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 29108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 30108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 33108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 29
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 30
0
10
20
30
40
Time t
Charring
depth
d char0
or
d charn
[mm]
t ch
1
2a
t f
2b
2c
t a
25 mm
Charring model for init ially protected surfaces
For gypsum plasterboards type F tch lt tf
β β sdot= 2)2( b phase
β β =)2( c phase
β β lt)2( a phase
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 31108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 32108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 31
Fire behaviour of initially protected surfaces
Charring depth (mm)
Fire time (min)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 32
Time of start of charring
bull For wood-based panels
bull For gypsum plasterboards type A H or F
(one layer)
Where hp is the thickness of the panel in mm
min211451282 =minussdot=cht
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 34108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 33
ge l a m
i n
Failure modes of protective boards
bull Thermal degradation (mechanical failure)
of the boards
bull Pull-out failure of fasteners due to
excessive charring of t imber member
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 34
Failure modes of protective boards
bull Wood-based panels tch = tf
bull Gypsum plasterboards type A or H tch = tf
bull Gypsum plasterboards type F
bull No generic failure times given in EN 1995-1-2
bull To be determined by testing (prEN 13381-7)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 35108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 35
Design of timber structures in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 36108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 36
Analysis of
bull entire structure (global analysis)
bull sub-assemblies (eg frames)
bull members (eg walls floors columns beams)
Verification methods for the load-bearing
function
fidfid RE le
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 37108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 38108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 37
Verification methods for the load-bearing
function
fidfid RE le
bull Combinations of actions for accidental design
situations (EN 1990)
bull As simplification for residential social
commercial and administration areas
Edfi = 06Ed
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 38
20modfidfi
Mfi
f = f k
γ
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 39108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 40108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 39
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 40
fi20 k
= f f k
20modfidfi
Mfi
f = f k
γ
20
fractile
of rdquo coldrdquostrength
Design strength in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 41108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 41
Design strength in f irefi20 k = f f k
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 42108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 43108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 42
20modfidfi
Mfi
f = f k
γ
20
fractile
ofstrength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 43
20modfidfi
Mfi
f = f k
γ
partial factor = 10
20
fractile
of
strength
modification factor
(elevated temperature
and moisture)
Design strength in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 44108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 44
modfi 1=k
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
char layer
zero strength layer
effective cross-section
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 45108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 46108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 48108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 45
Reduced cross-section method
Material behaviour in f ire
Design of timber structures in fire
00nchar ef dkdd sdot+=
mm7d0 =
01k fimod =
kfi20fid f kf f sdot==
dcharn
k0d0
def
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 46
Section A-AFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
8 x 1 m = 8 m
4 m
4 m A - - - - A
Worked example
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
Material properties
Solid timber C24
f mk = 24 Nmm2
f c0k = 21 Nmm2
Emean = 11rsquo000 Nmm2
Glued laminated timber GL24h
f mk = 24 Nmm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 47108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 47
11 Perm load Finishing 009 kNm2
Topping 132 kNm2
Insulation 006 kNm2
Boards 028 kNm2
175 kNm2
Partitions 100 kNm2
12 Self weight
Secondary beam 120260 mm a=1m =gt 017 kNm2
Main beam 160735 mm a=4m =gt 017 kNm2
13 Live load Residential 20 kNm2 (ψ2 = 03)
1 Actions
Bemessungsmethode gemaumlss SIA 265
Worked exampleFinishing 6mm
Topping 60mm
Insulation 40mm
Boards 50mm
Main beam
GL24 160x735mm
Secondary beam
C24 120x260mm
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 48
2 Secondary beam ndash Fire resistance R 30
Solid timber 120260 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 120 - 2 (30 08 + 7) = 58 mm
hfi = 260 - (30 08 + 7) = 229 mm
Wfi = = 5069 103 mm3
f mdfi = kfi f mk = 125 24 = 300 Nmm2
( )kNm07
8
4123017001751M
2
fid =sdotsdotsdot+++
=
2fidm
2
fi
fidfid mmN030f mmN913
W
M=le==σ
Worked example
k0d0
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 49108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 49
3 Main beam ndash Fire resistance R 30
Glued laminated t imber 160735 mm (GL24h)
=gt Notional charring rate βn = 07 mmmin
Fire exposure on 3 sides tfireq = 30 min
bfi = 160 - 2 (30 07 + 7) = 104 mm
hfi = 735 - (30 07 + 7) = 707 mm
Wfi = = 8664 103 mm3
f mdfi = kfi f md = 115 24 = 276 Nmm2
2fidm
2
fi
fidfid mmN627f mmN613
W
M=le==σ
Bemessungsmethode gemaumlss SIA 265
k0d0
Worked example
( )kNm1118
8
28423017017001751fid
M =sdotsdotsdot++++
=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 50108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 50
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
k0cfificfid0c2
fi
fidfid f kkf mmN16
A
Nsdotsdot=le==σ
k0
d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
8 x 1 m = 8 m
4 m
4 m A - - - - A
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 51108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 51
4 Column ndash Fire resistance R 30
Buckling length = 30m k0d0
Worked example
mm3289898
129898
A
Ii
3
fi
fi
fi =
sdot
sdot==
0106328
3000
ififi ===λ
811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 52108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 53108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 54108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 55108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 56108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 57108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 52
4 Column ndash Fire resistance R 30
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
106
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 53
4 Column ndash Fire resistance R 30
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 160 - 2 (30 08 + 7) = 98 mm
hfi = 160 - 2 (30 08 + 7) = 98 mm
Afi = = 96 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN16
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =sdotsdotsdot++++=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 54
Use of massive
cross-sections
Increase of cross-
sections by charring
depth
Protection of the timberelements with non
combustible materials
Basic strategies
Material behaviour in f ire
Fire resistance of
60 minutes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 55
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
min3614188214h82t pch =minussdot=minussdot=
0
10
20
30
40
Timet
Charring
depth
d char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 56
51 Column ndash Fire resistance R 60
Protection w ith gypsum plasterboards Type A single layers 18mm
Worked example
0
10
20
30
40
Time t
Charring
depth
d char0or
d charn
[mm]
1
2a
25 mm
2b
t at f
min551
802
2536
2
2536t
min3614188214h82t
na
pch
=
sdot
+=
βsdot
+=
=minussdot=minussdot=
tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 57
51 Column ndash Fire resistance R 60
Solid timber 160160 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
k0
d0
Worked example
0
10
20
30
40
Time t
Charring
depthd char0
or
d charn
[mm]
1
2a
25 mm
2b
t at f tch = tf
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 61108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 58108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 58
51 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm823482482
12482482
A
Ii
3
fi
fi
fi
=sdot
sdot==
0126823
3000
ififi ===λ
121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 59108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 60108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 63108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 59
51 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
200k fic ==gt 121100032
21
143
0126
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 62108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 60
2fid0c
2
fi
fidfid mmN3521251200f mmN78
A
N=sdotsdot=le==σ
k0d0
Worked example
( )kN059
2
8423017017001751fid
N =sdotsdotsdot++++
=
51 Column ndash Fire resistance R 60
Solid timber 160160mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 min
Protection w ith gypsum plasterboards Type A 18mm
tch = 36 min ta = 515 min
bfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
hfi = 160 - 2 (25 + 85 08 + 7) = 824 mm
Afi = = 68 103 mm2
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 61
52 Column ndash Fire resistance R 60
Increase of cross-sections by charring depth (asymp 30 08 = 24mm)
Solid timber 210210 mm (C24) =gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 60 minbfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
k0cfificfid0c2
fi
fidfid f kkf mmN95
A
Nsdotsdot=le==σ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 62
52 Column ndash Fire resistance R 60
Buckling length = 30m k0d0
Worked example
mm928100100
12100100
A
Ii
3
fi
fifi =
sdot
sdot==
8103928
3000
ififi ===λ
811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 63
52 Column ndash Fire resistance R 60
Worked example
Solid
timber
Glued laminated timber
relfi
kcfi
270k fic ==gt 811100032
21
143
8103
E32
f
E
f
mean
k0cfi
050
k0cfifirel =
sdotsdot=
sdotsdot
π
λ=sdot
π
λ=λ
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 64108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 64
52 Column ndash Fire resistance R 60
Solid timber 210210 mm (C24)
=gt Notional charring rate βn = 08 mmmin
Fire exposure on 4 sides tfireq = 30 min
bfi = 210 - 2 (60 08 + 7) = 100 mm
hfi = 210 - 2 (60 08 + 7) = 100 mm
Afi = = 10 103 mm2
2fid0c
2
fi
fidfid mmN1721251270f mmN95
A
N=sdotsdot=le==σ
k0d0
Worked example
( ) kN0592
8423017017001751fidN =
sdotsdotsdot++++=
Connections in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 65108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 65
Fire test with a multiple shear s teel-to-
timber dowelled connection
Connections in f ire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 66108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 67108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 66
Only symmetrical three-member connectionsDowel-type fasteners (nails bolts dowels screws) and
connectors (split-ring shear-plate and toothed-plate
connectors)
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
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Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
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Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 67
Connections with
side members of wood
Simplifed rulesReduced load
method
Connections with
external steel plates
Connections with
dowel-type
fasteners
EN 1993-1-2(steel design)
Design by
testing
Timber connections
Axial ly loaded
screws
Connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 68108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 68
Connections with slotted-in steel plates
Connections with sidesteel plates
Connections with steel elements in fire
Multiple shear steel-to-timber
dowelled connection
Connection with side steel
plates and annular ringed
shank nails
Connections with steel elements in fire
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 69108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 69
Simplified rules ndash fire resistance determined by thickness of side members
and protective panels and fastener endedge distances
Reduced load method ndash lsquoload-carrying capacity vs timersquo assumed as one-
parameter exponential empirical model
afi
a3
a4
afi
afia4
afi
t1
Connections with side members of wood
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 70108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 70
Connections designed according to EN 1995-1-1
Fastener connector
type
Fire resistance
tdfi [min]
Provisions
Nails 15 d ge 28 mm
Screws 15 d ge 35 mm
Bolts 15 t1 ge 45 mm
Dowels 20 t1 ge 45 mm
Connectors (EN 912) 15 t1 ge 45 mm
d is the diameter of the fastener
t1 is the thickness of the side member
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 71108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 71
Greater fire resistance (not exceeding 30 min) by increasing
thickness of side members
width of the side members
end edge distance to fasteners
afi
a3
a4
afi
afia4
afi
t1
β n is the notional charring rate
k flux is a coefficient taking into accountincreased heat flux through the fastener
t req is the required fire resistance
t dfi is the fire resistance of the unprotected
connection (previous table)
Simplified rules ndash unprotected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 72108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 72
Wood panelling wood-based panels or gypsum plasterboard type A or H
Gypsum plasterboard type F
t ch is the time until start of charring of the protectedmember t ch = t ch (h p)
t req is the required fire resistance
t dfi is the fire resistance of the unprotected connection
hpafi
glued-in plugs
additional protection
using panels
fasteners fixing of the
additional protection
member providing
protection
bolt head
afi
member
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 73108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 73
Fixing of additional protection by nails or screws
Distance between fasteners
le 100 mm (along the boards edges)
le 300 mm (for internal fastenings)
Edge distance of fasteners gea
fi
Penetration depth of fasteners
ge 6middotd (wood-based panels or gypsum plasterboard type A or H)
ge 10middotd (gypsum plasterboard type F)
afi
afi
afi
afihp
additional protection
using panels
fasteners fixing of the
additional protection
la
char layer panel
unburnt timber
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 74108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 74
Connections with internal steel plates
width bst of the steel plate
(with unprotected edges)
steel plates narrower than the
timber member are protected if
bst
dg
dg
dg
dg
dg
dg
hp
hp
Unprotected edges in
general
R30 bst ge 200 mm
R60 bst ge 280 mm
Unprotected edges in
one or two sides
R30 bst ge 120 mm
R60 bst
ge 280 mm
plate thickness le 3 mm R30 dg ge 30 mm
R60 dg ge 60 mm
joints with glued-in strips or
protective wood based boards
R30 dg or hp ge 10 mm
R60 dg or hp ge 30 mm
Simplified rules ndash protected connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 75108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 75
lsquoLoad-carrying capacityrsquo vs Fire resistance
assumed as one-parameter exponential empirical model
model parameter k for each connection type and limited to a maximum fire exposure period
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 76108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 76
Load-carrying capacity after a given fi re exposure
EN 1995-1-1
Connection type k
Maximum period of
validity for k
Nails and screws 008 20 min
Bolts wood-to-wood (d ge 12) 0065 30 min
Bolts wood-to-wood(d ge 12)
0085 30 minDowels wood-to-wooda (d ge 12) 004 40 min
Dowels steel-to-wooda (d ge 12) 0085 30 min
Connectors (EN 912) 0065 30 min
a requires one bolt for every four dowels
F vRk is the characteristic load-carrying capacityat normal temperature
t dfi is the design fire resistance (in minutes)
k fi is a factor to convert 5-percentile values
to 20-percentile
γ Mfi is the partial safety factor for timber in fire
Connections Reduced load method
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 77108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 77
Connections Reduced load method
Fire resistance for a given load level
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 78108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 78
Steel-to-timber dowelled connection with internal steel plate
E d = 40 kN
E d
a 1 = 84 mm a 3 = 84 mm
a 4 = 55 mm
a 2 = 50 mm
a 4 = 55 mm
GL 24h rarr ρ k = 380 kgm3
Oslash12 dowels class 68 rarr f u = 600 Nmm2
t dfi ge 30 min
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 79108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 79
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 80108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 80
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 81108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 81
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 82108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 82
Connections Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 83108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 83
Connections Worked example
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 84108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 84
g p
timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 85108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 85
Charring behaviour
Timber with steel plates Timber with steel plates and
steel dowels
Timber
850
700
580
400
200
20
Temp [degC]
850
700
580
400
215
74
Temp [degC]
850
700
580
400
230
114
Temp [degC]
Influence of steel plates and steel dowels
on charring
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 86108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 86
Fire design model for multiple shear
steel-to-timber dowelled connections
Rdtfi
= Aef
f t0k
kfi
t1 thickness of timber
side member
Connections with steel elements in fire
Fire design model for multiple shear steel-to-
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 87108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 87
g p
timber dowelled connectionsFire design model for multiple shear
steel-to-timber dowelled connections
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 88108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 88
bull Parametric fire exposure
bull Advanced calculation methods
bull Load-bearing timber frame assemblies with
cavity insulation
bull Charring of members in wall and f loor
assemblies with void cavities
bull Analysis of the separating function of wall andfloor assemblies
Informative annexes
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 89108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 89
bull Thermal analysisEffective thermal properties include effects of mass
transport and cracking and surface recession of
char-layer (only valid for standard fire exposure)
bull Structural analysisThermo-mechanical properties include transient
effects of combined moisture and elevatedtemperature and mechano-sorptive creep
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 90108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 90
Advanced calculation methods (eg FE analysis)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 91108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 91
Timber frame assemblies with cavities completely
filled with insulation
b b
d c h a r n
h
Modification factors kmodfi are given
Fire separating function of
ll d fl
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 92108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 92walls and floors
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 93108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 93
bull Criterion I (insulation)
bull ∆T le 140k
(average temperature rise)
bull ∆T le 180k
(maximum temperature rise)
bull Criterion E (integrity)
bull no sustained flaming or hot gases
to ignite a cotton padbull no cracks or openings in
excess of certain dimensions
Insulation I
Integrity E
Requirements for separating function
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 94108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 94
ins ins0i pos ji
=
sumt t k k
Components additive method
Separating function of wall and floor assemblies
Calculation of the time t ins by adding thecontribution to the fire resistance of the
different layers
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 95108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 95
Components additive method
ins ins0i pos ji
=
sumt t k k
Basic value of layer i
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 96108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 96
ins ins0i pos ji
=
sumt t k k
Position coefficient
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 97108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 97
The coefficient kpos considers the influence of the
position of the layers in the assembly
t ins1 gt t ins2
Coefficients of design model
Position coefficient kpos
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 98108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 98
ins ins0i pos ji
=
sumt t k k
Joint coefficient
for joints not backedby eg battens
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 99108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 99
ba dc b
Heat paths
Components additive method
Separating function of wall and floor assemblies
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 100108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 100
1 Wall ndash Fire resistance EI 60 Geometry
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 101108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 101
2 Wall ndash Fire resistance EI 60 Basic value of layers
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min5175141h41t p0ins =sdot=sdot=
min11h950h950t pp0ins =sdot=sdot=
min16018020kh20t densinsi0ins =sdotsdot=sdotsdot=
min11h950h950t pp0ins =sdot=sdot=
min5175141h41t p0ins =sdot=sdot=
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 102108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 102
3 Wall ndash Fire resistance EI 60 Posit ion coefficients
Separating function Worked example
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 103
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 103108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 103
4 Wall ndash Fire resistance EI 60 Joint coefficients
Layer 1 to 4 k j = 10 (layer backed by other layer)
Layer 5 k j = 10 (filled joints)
Separating function Worked example
ins ins0i pos j
i
=sumt t k k
W k h lsquoSt t l Fi D i f B ildi di t th E d rsquo B l 27 28 N b 2012 104
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 104108
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 104
5 Wall ndash Fire resistance EI 60
Layer 1 Gypsum plasterboard type A 125 mm
Layer 2 Plywood 12 mm
Layer 3 Rock fibre batts 80 mm ρ = 26 kgm3
Layer 4 Plywood 12 mm
Layer 5 Gypsum plasterboard type A 125 mm
Separating function Worked example
min742151701110116801101517tins =sdot+sdot+sdot+sdot+sdot=
ins ins0i pos j
i
=sumt t k k
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 105
Steinhausen 6 storeys (Switzerland)
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 105108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 105
Zuumlrich 7 storeys (Switzerland)
Lugano 6 storeys
(Switzerland) Baar 5 storeys (Switzerland)
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo Brussels 27 28 November 2012 106
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 106108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 106
Fire safety plan with all fire safety measures
Careful planning and detailing
Professionally implementation
of fire safety measuresduring the execution
Periodic controls and
maintenance
The intensity of maintenance and controls must be set
depending of the type of structures and the type and
importance of the building
Quality of construction
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 107
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 107108
Workshop Structural Fire Design of Buildings according to the Eurocodes ndash Brussels 27-28 November 2012 107
bull EN 1995-1-2 has fil led many gaps in the knowledge
of structural timber design in fire
bull However some problems are sti ll to be solved
hopefully before the next generation of Eurocodes
will be published
bull Further knowledge in
ldquo Fire safety in Timber Buildingsrdquo
Technical guideline for Europe
SP Report 2010
Concluding remarks
Workshop lsquoStructural Fire Design of Buildings according to the Eurocodesrsquo ndash Brussels 27-28 November 2012 108
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther
7232019 08 Frangi Ec Firedesign Ws
httpslidepdfcomreaderfull08-frangi-ec-firedesign-ws 108108
Workshop Structural Fire Design of Buildings according to the Eurocodes Brussels 27 28 November 2012 108
bull Simplification (ldquo only one design principle
shall be availablerdquo )
bull Harmonisation (Annexes should be movedto the main part other parts and other ENs)
bull Improvement extension
bull Cross-laminated timber panel (new rules)
bull Timber-concrete-composite elements(new rules)
bull Connections (Improved rules)
bull Failure of claddings (Improved rules)
Future evolution EN 1995-1-2
bull Evolut ion group D Dhima A Frangi (Chair) A Just P Kuklik
J Schmid N Werther