Prof. Stijn MATTHYS

Workshop of the Belgian fib member group - 23 January 2020

fib REPORT ON DESIGN OF CONCRETE MEMBERS WITH FRP

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WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

01

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03 05

04

WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

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FRP (fibre reinforced polymer)

FRP → thousands of

continuous fibres in a

polymer matrix, forming a

composite with high

strength, stiffness and

durability

+ high strength

+ low density (≤ 20% than steel)

+ excellent durability

+ high E-modulus (comparable with steel)

+ excellent fatigue characteristics

+ ease of application

- limited failure strain

- higher material cost

- specific durability issues possible (UV, alkalis)

- fire resistance

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FRP reinfrocement

FRP strip & sheets

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Tensile diagram

0

500

1000

1500

2000

2500

0.0 2.0 4.0 6.0 8.0 10.0

Rek [%]

Sp

an

nin

g [

N/m

m²]CFRP

Stalen plaat

AFRP

GFRP

G: glass; C: carbon; A: aramide; B: basalt; SC: steel cord

σ (GPa)

ε

Mild steel

0.02 0.04

2

6

4

GFRP

AFRPCFRP

Steel plate

Strain

Str

ess GFRP/BFRP

CFRP/SCRP

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Typical values (fibre volume ~ 60 %)

Property CFRP GFRP AFRP Steel plate

Tensile strength [MPa] 600-3000 400-1600 600-2500 300-600

Modulus of elasticity [GPa] 80-500 30-60 30-125 200

Failure strain [%] 0.5-1.8 1.2-3.7 1.8-4.0 >10

Density [kg/m³] ~1550 ~1950 ~1400 7850

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Ciment armé[1st patent 1851]

FRP strengthening[1987]

FRP prestress[1980]

1990’s manyapplications & growing

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Reinforcing and strengthening with FRP

FRP rebars and prestressing reinforcement Externally applied reinforcement

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FRP reinforcement in new structures

Niche markets

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Externally applied reinforcement

Ease and flexibility of application

01

02

03 05

04

WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

fib T5.1 ‘FRP

reinforcement for

concrete’

Part of fib

commission 5

‘Reinforcements’

Meetings twice per

year

90 members

Stijn Matthys

Maurizio Guadagnini

Task Group Chair

Deputy Chair

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Work modus → supporting networks

Action TU1207

FINISHED

NEW

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fib Bulletins by Task Group 5.1

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fib FRP course

URL: www.frpcourse.eu

fib Workshop 12 November 2019, Naples

Presentazione del bollettino fib 90

“Externally applied FRP reinforcement for concrete structures” - Bulletin 90

fib B90 on Design of

Concrete Members

Strengthened with

Externally

Applied Reinforcement

19/50

T5.1

Technical bulletins

FRP in EC2

FRP in MC2020

Compendium

Training

Running activities

01

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03 05

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WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

1. General

2. Materials, systems and techniques

3. Basis of design and structural analysis

4. Durability considerations

5. Bond

6. Ultimate limit states for predominant

static loading and fatigue

7. Serviceability limit states

8. Ultimate limit states in seismic retrofitting

9. Detailing

10. Practical execution and quality control

ISBN 978-2-88394-131-1

240p (vs 138p for fibB14)

Wider scope of techniques

NSM added in detail

Updated design formulations

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Types of EAR

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► increase flexural capacityincrease stiffness (less deflections)

► increase shear capacity

► strengthening of columns

Types of strengthening

Vuurmolen Overijse

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Table 1. Material safety factors for FRP tensile strength.

Design situation Safety factor*

Persistent/transient 1.25

Accidental 1.00

* These safety factors imply that the quality control provisions on the FRP materials and products,

as well as their installation, are according with the provisions of Chapter 10. The safety factors

adopted in seismic retrofitting are higher, see Chapter 8.

Constitutive material models

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xlim ≤ 0.45d for concrete type C50/60 or lower

xlim ≤ 0.35d for concrete type C55/67 or greater

x the depth of the compression zone

d the effective beam depth

Warning by sufficient curvature

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unstrengthened

(Q1)

Qd1

strengthened

(Q2 > Q1)Qd2

accidental loss of FRP EBR

→ failure or not?

Q2 > Q1

Load and

material safety

factors

Reduced safety

factors (or = 1)

(EC1)

Accidental design situation

In this case, extra attention should be paid to all relevant accidental

situations and specific points for the designer are listed.

01

02

03 05

04

WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

31/50

Upcoming (1): FRP in EC2

CEN/TC 250/SC 2/WG 1/TG 1

Strengthening and reinforcing with fibre reinforced polymers

Eurocode 2

Scope:

• Embedded FRP

reinforcement

• Strengthening of existing

concrete structures with

FRP

Note: scope is more narrow than in

fib Model Code.

Proposed annexes (after

considering Project Team 3

comments); comments national

CEN bodies to be addressed

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Upcoming (2): FRP in MC2020

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Upcoming (3): Design examples

NN

Design examples for reinforced concrete members reinforced or strengthened with FRP

PART I – Strengthening of concrete structures with externally applied reinforcement

# Title Main Autors Additional contributors

3 STRENGTHENING OF RC MEMBERS

31 Flexural strengthening by EBR

311 One-way slab Gent (Arslan, Stijn) Thanasis T., Christoph C.

312 Two-way slab Timisoara (Florut) Gabriel S.

313 RC beam Milano (Tommaso) Thanasis T., Stijn M.

314 One-way slab with prestressed EBR Lodz (Renata) Christoph C., José S-C

315 Statically undetermined RC beam abt (Mark V.) Stijn M., Eva O.

32 Flexural strengthening by NSM

321 One-way slab Minho (Joaquim, José) Renata K.

322 RC beam Milano (Tommaso) Joaquim, Renata K., Sandor S.

323 RC beam with prestressed NSM Lodz (Renata)

33 Shear strengthening

331 EBR shear strengthening Milano (Tommaso)

332 EBR shear strengthening continuous girder UPC (Eva), USFD (David E.)

332 NSM shear strengthening Minho (Joaquim, José) Renata K.

34 Confinement of columns

341 EBR confinement of axially loaded columns DUTH (Theodoros) Kocaeli (Erkan E.)

Confinement with EBR Milano (Tommaso)

342 EBR strengthening in combined bending DUTH (Theodoros)

343 EBR confinement of slender columns Gian Piero Lignola (Napoli)

4 STRENGTHENING OF PC MEMBERS

410 Flexural strengthened with prestressed EBR/NSM Lodz (Renata) Christoph C.

420 Shear strengthening UPC (Eva), Lodz (Renata) Arslan

5 SEISMIC RETROFITTING

51 Column: lateral drift – lap splice – shear DUTH (Theodoros) Ciro, Erkan E., Thanasis T.

52 In plane shear of RC walls Timisoara (Florut)

53 Beam-column joint Naples (Ciro, Andrea) Thanasis T.

541 Strengthening of RC frame (FRP combined with steel bracing)Naples (Ciro & co)

542 Seismic strengthening - whole building = 54 Nothingham (Georgia T.), Thrace (Souzana T.)

6 ACCIDENTAL SITUATIONS/SPECIAL CASES

61 Fire design of strengthened RC member UGent (Alessandro,Stijn) Luke B.

62 Strengthening for blast UGent (Azer, Stijn)

63 Strengthening of filigree wideslab joints abt (Mark V., Niek P.)

64 Strengthening for impact Naples (Marco)

PART II – Reinforcing of concrete structures with FRP reinforcement

# Title Main Autors Additional contributors

7 RC MEMBER DESIGN

71 Flexural design of ribbed floor Maurizio, Ana, Lluis (see slide Maurizio)

Flexural design of continues T-beam + slab on top Maurizio, Ana, Lluis

72 Flexural design of one-way slab Reykjavik (Halldór, Eythor)

73 Flexural design of two-way slabs same team as 71

74 Shear design of beams Maurizio, Ana, Lluis

75 Long-term & durability evaluation André

8 PC MEMBER DESIGN

81 Flexural design Ted Donchev will make a first darft and then we see if we feel we can included it or if it is beyond the scope for the moment being

9 ACCIDENTAL SITUATIONS

91 Fire design Naples (Antonio B, Emidio N)

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Upcoming (4): Compendium

Compendium for Interventions on Concrete

Structures [fib T8.1 & T3.4]

1. Protection Methods

1.1. Surface protection methods

1.2. Electrochemical methods

2. Repair Methods

2.1. Material reinstatement

2.2. Concrete crack repair

3. Strengthening Methods

3.1. Strengthening existing members

3.2. Adding new structural members

3.3. Adding new systems/devices

FRP jacketing

Externally applied FRP

01

02

03 05

04

WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

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Research on structural repair

‘EXTERNALLY APPLIED REINFORCEMENT’ TECHNOLOGIES:

Surface bonded FRP (fibre reinforced polymer) reinforcement

Textile reinforced mortar overlays

Short fibre reinforced high performance mortar overlays

Post-tensioning with shape memory alloys

Strengthened structures under fire, blast or impact

→ material innovations, bond, structural behaviour, design &

modelling

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FRP strengthened slabs under blast

In collaboration with RMA

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DuRSAAMPhD Training Network on Durable, Reliable and Sustainable Structures with Alkali-Activated Materials

→ www.dursaam.eu

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Alkali-activation technology route

→ for new concrete→ for repair of concrete by means of textile reinforced mortar

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Durability, repair & maintenance of concrete structures

By-products & recycledmaterials as raw material forconcrete and concrete repairtechnologies

Residues

47/50

Currently we are developing the new AAM based TRM

01

02

03 05

04

WHAT IS

FRP &

NON-METALLIC

REINFORCEMENT

fib

TASK GROUP

T5.1

HIGHLIGTHING

SOME RUNNING

WORK

HIGHLIGTHING

THE LATEST

ACHIEVEMENT

LINK WITH

UGENT

RESEARCH

fib T5.1 members are acknowledged

for their support and their continuous

involvement in the activities.

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Prof. dr. ir. Stijn Matthys

UGent DuraBUILDmaterials

DEPARTMENT OF STRUCTURAL ENGINEERING AND BUILDING MATERIALS

Technologiepark-Zwijnaarde 60, 9052 Gent

stijn.matthys@ugent.be

www.ugent.be/ea/structural-engineering

www.dbm.ugent.be