03 April 2013

1

La inclusion del HRF como material con fines estructurales en el nuevo Codigo Modelo 2010

Group Concrete Structures

Seminario sobre experienceas internationales del Hormigon Reforzado con Fibras

03 April 2013 2

Do we really need codes?

...Meeting TG 8.6 Marseille 2012

03 April 2013 3

FRC and UHPFRC: one family or irreconcilable groups?

C20 C80 C180 C200

fib TG 8.3 FRC fib TG 8.6 UHPFRC

03 April 2013 4

Softening versus hardening behaviour in axial tension

Softening hardening

03 April 2013 5

Softening versus hardening: hard to define

Different response of structures made of FRC having a softening or hardening behaviour under uniaxial tension or bending

03 April 2013 6

New Model Code for Concrete Structures

Multi-level design strategy

03 April 2013 7

Test for determing FRC properties in tension

03 April 2013 8

Test for determing FRC properties in tension

2,2

3

sp

j

jRbh

lFf

03 April 2013 9

Definition of strength intervals

The strength interval is defined by two subsequent numbers in the series: 1,0 1,5 2,0 3,0 4,0 5,0 6,0 7,0 8,0 ….. [Mpa]

wherease the letters a, b, c, d, e correspond to the residual strength ratios: a if 0,5 fR3k/fR1k 0,7 b if 0,7 fR3k/fR1k 0,9 c if 0,9 fR3k/fR1k 1,1 d if 1,1 fR3k/fR1k 1,3 e if 1,3 fR3k/fR1k 1,5 Example: a fibre concrete denoted with “3b” has a strength between 3 and 4 Mpa and a fR3k/fR1k ratio ranging between 0,7 and 0,9

03 April 2013 10

Constitutive design laws (Level I)

3

3RFtu

ff

Rigid plastic model:

Linear model:

145,0 RFts ff

0)2,05,0( 13

3

RRFtsu

FtsFtu fffCMOD

wff

03 April 2013 11

Design of FRC members: design in shear

cpck

ctk

Ftukl

c

fRd ff

fkv 15.0)5.71100

18.03/1

,

03 April 2013 12

Constitutive design laws (Level I)

K-values added for different situations For isotropic fibre orientation K = 1,0

03 April 2013 13

The “K-factor” versus “Design by Testing”

0.0

0.5

1.0

1.5

2.0

2.5

0 4 8 12 16 20

Mid-span deflection [mm]

Be

nd

ing

mo

me

nt [k

Nm

]

X Y

Casting in Y-direction

03 April 2013 14

Taking advantage of fibre orientation

Production of precast elements for Haneda airport platform: determining the

most favourable casting method in combination with design by testing

03 April 2013 15

K-factor: relevance of casting method

Unforeseen sliding surface in UHPFRC prestressed beam

03 April 2013 16

Model Code for Concrete Structures

Concrete’s Design for structural safety Design for serviceability Design for durability Design for sustainability

- Constitutive relations for wide range of concrete’s

- Fibres as a reinforcing material - Service life design - Reliable NLFEM analysis - Maintenance as a design issue - Conceptual design

03 April 2013 17

Model Code for Concrete Structures

Concrete’s Design for structural safety Design for serviceability Design for durability Design for sustainability

03 April 2013 18

Introduction of “time” in a structural design code

Recording

Specification of conservation strategy

Determination of tactic and regime for condition control

Revision of conservation strategy and tactic

Final adoption of inspection regime

Start of through life condition monitoring

Condition survey

Condition assessment

Execution of chosen intervention

Condition evaluation

and decision-making

Condition survey (after construction or re-design)

Condition assessment (after construction or re-design)

i = 1 ? n

fib Model Code 2010

03 April 2013 19

New interpretation of aspect of “time” with regard to design and maintenance of concrete structures

03 April 2013 20

New interpretation of aspect of “time” with regard to design and maintenance of concrete structures

03 April 2013 21

Assessing the residual capacity

03 April 2013 22

Project Calandbridge the Netherlands

03 April 2013 23

Removal of the asphalt layer

03 April 2013 24

Preparing the steel surface

03 April 2013 25

Applying the epoxy bond layer

03 April 2013 26

Placement of the reinforcement

03 April 2013 27

Leveling the new concrete

03 April 2013 28

Typical characteristics of the new deck

- Thickness of concrete deck 60 mm

- Deck ready for use in 120 hours - Reduction of stress variation of 60% in bearing structure - Reduced vibration and noise

03 April 2013 29

Model Code for Concrete Structures

Concrete’s Design for structural safety Design for serviceability Design for durability Design for sustainability

03 April 2013 30

Model Code: design for sustainability

Concrete’s Level I Method Comparison of green house gas emission: material substitution: BREAM (UK), HQE (France), LEED (USA), CASBEE (Japan), Green Star (Netherlands)

Level II Method Environmental Impact Calculation (EIC): - Measure of Embodied Energy - Measure of CO2 - Calculation of Global Warming Potential (GWP)

Level III Method Full life cycle assessment (LCA), including durability and maintenance considerations, recyle and reuse

03 April 2013 31

EIC: Environmental Impact Calculation

- CO2 Emission - EE = Embodied Energy Energy consumed in the production of Portland Cement is estimated to be 4.88

MJ/kg and the total energy in the production of steel 23.7 MJ/kg

(Struble and Godfrey (2004)

- GWP = Global Warning Potential Contribution of CO2 on global warming, calculated through the equivalence of the effect of greenhouse gas (Elrod, 1999): for simplicity: 100 – year GWP = CO2 + 298 Nox + 25CH4

03 April 2013 32

Comparison of two bridges (Voo/Foster, 2010)

03 April 2013 33

Comparison of two bridges

UHPC: - No shear reinforcement only fibres - fcm = 160 MPa

03 April 2013 34

Comparison of two bridges (Voo/Foster 2010)

03 April 2013 35

Two solutions for a 180 m long retaining wall (Voo/Foster, 2010)

Construction of retaining wall for drain channel in Ipoh, Malaysia, 180 m long, 1.5 m high

Solution in conventional concrete and UHPFRC (fcm =160 N/mm2)

03 April 2013 36

Results of EIC for retaining walls

03 April 2013 37

GSE - Bridge Haneda Aiport Tokyo

- Concrete girder C180

- Concrete deck C40

- 7 precast beams C180

03 April 2013 38

GSE Bridge Haneda Airport Tokyo

Advantages of the use of UHPFRC

- 40% Weight reduction

- 20% Reduction of cross-sectional depth (from 2.50 m to 2.00 m)

- Durability

03 April 2013 39

Concrete viaducts the Netherlands

Reduction of height of concrete deck = hughe reduction of soil supply for bridge ramps

03 April 2013 40

Model Code 2010

Design for structural safety Design for serviceability Design for durability Design for sustainability: elegance, beauty, harmony with environment, functionality, social value and acceptance, durability, reduction of nuisance for environment

Glenmore/Legsby pedestrian bridge Canada 2007

Span 53 m Suspended beams 34 m (h = 1,1 m) Crossing 8 traffic lanes Important aspects - Assembly in 8 hours - No intermediate support

03 April 2013 42

Elegant structures in harmony with environment

MuCem Marseille 2012

03 April 2013 43

Balconies Denmark

Foto B. Aarup Hi-con Denemarken

Balconies Poptahof Delft 2011

Proofloading 1500 kg/m3

03 April 2013 45

Conclusions

- Adequate design recommendations for UHPFRC are a “must”: MC2010 gives a “level I approach” suitable for any fibre reinforced concrete -- Tailored recommendations (“Level II) are given for traditional concrete (RILEM) en HPFRC (fib TG 8.6) - UHPFRC can play an important role in service life design - UHPFRC is very suitable for retrofitting - Adequate criteria for sustainability of structures can become a hard argument for choosing this material - Architecture and functionality is a winning combination (conceptual design)