6.07.2004mid-term assessment london july 5-6 20041 wp 14 – high performance fiber reinforced...

6.07.2004 Mid-term assessment London July 5-6 2004

1

WP 14 – WP 14 – High Performance Fiber High Performance Fiber Reinforced Cementitious Reinforced Cementitious

CompositesComposites for Rehabilitationfor Rehabilitation

WP leader: WP leader: Dr. E. Denarié, MCS-EPFL (CH)Dr. E. Denarié, MCS-EPFL (CH)

Contractors:Contractors: MCS-EPFL (CH), Prof. E. BrühwilerMCS-EPFL (CH), Prof. E. BrühwilerDr. K. Habel, Dr. J.P. Charron, A. Kamen, J. Wuest, Dr. K. Habel, Dr. J.P. Charron, A. Kamen, J. Wuest, R. Gysler, S. DemierreR. Gysler, S. Demierre

LCPC (France), Dr. P. RossiLCPC (France), Dr. P. Rossi

TRL (UK), Dr. R. WoodwardTRL (UK), Dr. R. Woodward


2

OutlineOutline

1.1. Conceptual approachConceptual approach2.2. Properties of UHPFRCProperties of UHPFRC3.3. Objectives of WP 14Objectives of WP 144.4. Progress at mid termProgress at mid term5.5. State of the Art ReviewState of the Art Review6.6. Protective functionProtective function7.7. Structural responseStructural response8.8. Future works Future works 9.9. Expected benefitsExpected benefits10.10. ReferencesReferences


3

1. Conceptual approach1. Conceptual approach

Local « hardening » of critical zones subjected to severe mechanical or environmental loads


4

1.1. Ultra compact HPFRCC (UHPFRC) provide a Ultra compact HPFRCC (UHPFRC) provide a long-term durabilitylong-term durability in order to in order to avoid avoid multiple interventionsmultiple interventions on structures during on structures during their service life. their service life.

2.2. Ultra compact HPFRCC materials can be Ultra compact HPFRCC materials can be applied:applied:

• as thin as thin watertight overlayswatertight overlays , ,

• as as repair or reinforcement layers, repair or reinforcement layers, with a with a thickness from 20 to 50 mm, thickness from 20 to 50 mm, alone or alone or combined with reinforcement bars, combined with reinforcement bars,

• for for prefabricated elementsprefabricated elements such as curbs, such as curbs,

• in in critical zonescritical zones such as transitions from such as transitions from joints to the main structural elements. joints to the main structural elements.

MotivationMotivation


5

Rehabilitation strategyRehabilitation strategy


6

2. Ultra compact HPFRCC (UHPFRC)2. Ultra compact HPFRCC (UHPFRC)

• Ultra compact cementitious matrix.Ultra compact cementitious matrix.• Excellent resistance towards ingress of water, gases and detrimental Excellent resistance towards ingress of water, gases and detrimental

substances such as chloride contaminated water.substances such as chloride contaminated water.• Self-compacting.Self-compacting.• Reinforcement with short steel fibers (lReinforcement with short steel fibers (lff=10 mm) at a very high =10 mm) at a very high

dosage: 480 kg/mdosage: 480 kg/m33..• Outstanding mechanical properties with significant tensile strain Outstanding mechanical properties with significant tensile strain

hardening.hardening.


7

Mechanical properties of Mechanical properties of UHPFRCUHPFRC

UHPFRC(CEMTECmultiscale®)

NC

fcc

[MPa] 16851

Ecc [GPa] 48 38

fct [MPa] 11.0 3.4

fct,1st [MPa] 9.1 -

Tensile behaviour of UHPFRC

Mechanical properties at 28 days (mean values) NC: normal concrete

CEMTECmultiscale® developped by Rossi et al. (2002)

Habel (2004)


8

3. Objectives of WP 143. Objectives of WP 14

• Demonstrate applicability and advantages of Demonstrate applicability and advantages of HPFRCC materials for the rehabilitation of HPFRCC materials for the rehabilitation of concrete road infrastructure components concrete road infrastructure components (including aspects of global Life-Cycle-Cost in (including aspects of global Life-Cycle-Cost in relation with WP relation with WP 112). 2).

• Make a first step towards the optimisation of Make a first step towards the optimisation of these materials for rehabilitation. these materials for rehabilitation.

• Provide guidelines for use of these materials Provide guidelines for use of these materials and their further optimisation (numerical and their further optimisation (numerical simulation tools, test methods, limit states for simulation tools, test methods, limit states for design, etc.)design, etc.)..


9

• Properties in fresh state – processing.Properties in fresh state – processing.• Combination with bituminous concrete (adhesivityCombination with bituminous concrete (adhesivity). . • Early age and long term behavior.Early age and long term behavior.• Mechanical compatibility with substrate.Mechanical compatibility with substrate.• Physico-chemical compatibility with substrate.Physico-chemical compatibility with substrate.• Protective function - effect of damage on transport Protective function - effect of damage on transport

properties.properties.• Influence of geometry of element to be repaired.Influence of geometry of element to be repaired.• Statistical distribution of properties.Statistical distribution of properties.• Test methods and compliance criteria.Test methods and compliance criteria.• Modelling of mechanical behavior.Modelling of mechanical behavior.• Design methods.Design methods.

Main issues for applicationMain issues for application


10

Composite structuresComposite structures

Mechanical compatibility with substrate.Mechanical compatibility with substrate.Material properties + RestraintMaterial properties + Restraint


11

TasksTasks

WP 14 is divided into 5 tasks, as WP 14 is divided into 5 tasks, as follows:follows:

• 14.1 Preliminary Study14.1 Preliminary Study• 14.2 Testing14.2 Testing• 14.3 Interpretation – modelling14.3 Interpretation – modelling• 14.4 Numerical parameter study14.4 Numerical parameter study• 14.5 Specifications – documents 14.5 Specifications – documents

for applicationfor application


12

MilestonesMilestones

Milestone M4:Milestone M4: Identification of most important Identification of most important phenomena for defining main test programme. phenomena for defining main test programme. Results of numerical simulations and preliminary Results of numerical simulations and preliminary tests available. Date due: Month 6tests available. Date due: Month 6

Milestone M12:Milestone M12: Selection of materials for main test Selection of materials for main test series of HPRFCC. Preliminary test results and series of HPRFCC. Preliminary test results and conclusion concerning materials for the main tests conclusion concerning materials for the main tests available. Date due: Month 12available. Date due: Month 12

Milestone M18:Milestone M18: Choice of on site applications for Choice of on site applications for pilot tests of HPFRCC. Results and interpretation of pilot tests of HPFRCC. Results and interpretation of main test series available. Date due: Month 21main test series available. Date due: Month 21


13

DeliverablesDeliverables

D13:D13: Report on preliminary studies for the use of HPFRCC for Report on preliminary studies for the use of HPFRCC for rehabilitation of road infrastructure componentsrehabilitation of road infrastructure components ((Mon.18Mon.18))

D18:D18: Test report on laboratory testing of UHPFRCTest report on laboratory testing of UHPFRC ( (Mon.24Mon.24))D22:D22: Test report on pilot field trials of UHPFRCTest report on pilot field trials of UHPFRC ( (Mon.30Mon.30))D 25: D 25: Specifications for the use of CI and UHPFRC (Specifications for the use of CI and UHPFRC (Month 33Month 33))D26:D26: Modelling of UHPFRC in hybrid structuresModelling of UHPFRC in hybrid structures ( (Mon.33Mon.33))D31: D31: Guidelines for the use of UHPFRC Guidelines for the use of UHPFRC WP 12 ( WP 12 (Mon. 36Mon. 36))


14

4. Progress at mid-term4. Progress at mid-term


15

5. State of the art Review5. State of the art Review

Relevant documents (scientific, technical, norms, guidelines, etc.) from following countries were taken into consideration:

• France, Switzerland, Belgium, Canada• Germany, Austria• United Kingdom, USA• Italy• Japan, China• Denmark, Sweden, Norway


16

b) Measurement of the air permeability

a) Air permeability of new layers on composite beams, Habel (2004)

6. Protective function6. Protective function


17

Serviceability of UHPFRCServiceability of UHPFRC

• Assess the Assess the influence of cracking on the influence of cracking on the permeabilitypermeability of a UHPFRC of a UHPFRC

• Suggest serviceability limit statesSuggest serviceability limit states for an for an UHPFRC according to exposure conditionsUHPFRC according to exposure conditions

• OptimiseOptimise composite UHPFRC-concrete composite UHPFRC-concrete structuresstructures


18

Experimental techniquesExperimental techniques

• Uniaxial tensile testUniaxial tensile test• Measurement basis : 100 mmMeasurement basis : 100 mm• Specimen unloaded after predefinedSpecimen unloaded after predefined

deformation is reacheddeformation is reached• Core of Core of = 100 mm extracted= 100 mm extracted


19

• Glycol permeability Glycol permeability testtest

• Source of variability: crack Source of variability: crack pattern and heterogeneitypattern and heterogeneity

Permeability of damaged Permeability of damaged UHPFRCUHPFRC

• Damage testDamage test

tt loadingloading = 0.25 %= 0.25 %• tt unloading unloading 0.13 % 0.13 %

0

2

4

6

8

10

12

0 0,05 0,1 0,15 0,2 0,25 0,3

Ten

sile

str

ess

(MP

a)

Deformation, t (%)

t unloading = 0.12 %



Measurement basis = 100 mm


20

Tensile limit states for Tensile limit states for permeabilitypermeability

0

3

6

9

12

15

18

21

0 0.1 0.2 0.3 0.4 0.50

125

250

375

500

625

750

875

Deformation,t (%)

Str

ess

in U

HP

FR

C (

MP

a)

UHPFRC

Stress in steel bars (M

Pa)

fy = 700 MPa

fy = 500 MPa

Water- tightness

Prejudicialcracking

Unprejudicialcracking

Localized crack in UHPFRC

Steel bar

Charron et al. (2004)


21

Structural applicationStructural application

• Hybrid beam made of NC and UHPFRCHybrid beam made of NC and UHPFRC

As,low = 1010 mm2

As,upp = 339 mm2

As,UHPFRC = 314 mm2

UHPFRC50

150

NC

300 [mm]

F FUHPFRC

NCDeflection

24001200 1200

0

10

20

30

40

50

60

0 4 8 12 16 20

Force [kN]

Rehabilitation with UHPFRCRehabilitation with NC

Deflection [mm]

Habel (2004)Charron (2004)


22

Structural application (…)Structural application (…)

• Load limitationsLoad limitations• Avoid high creep deformations, Avoid high creep deformations, cc < 0.5 f < 0.5 fcc

• Protect reinf. bars against corrosion, Protect reinf. bars against corrosion, ss limited [BAEL, limited [BAEL, 1999]1999]

Use NC specifications for UHPFRC :

• conservative design

• benefits provided by UHPFRC not optimal

0

10

20

30

40

50

60

70

0 4 8 12 16 20

Force [kN]


Deflection [mm]

Water- tightness

Prejudicialcracking


c < 0.5*Fc

s <

24

0 M

Pa

s <

15

0 M

Pa


23

Structural application (…)Structural application (…)

• Load capacity limitationsLoad capacity limitations• Avoid high creep deformations, Avoid high creep deformations, cc < 0.5 F < 0.5 Fcc

• Protect reinf. bars against corrosion, Protect reinf. bars against corrosion, ss limited by limited by permeabilitypermeability

Use UHPFRC limits suggested in this study :

• design less conservative

• better use of UHPFRC potential

0

10

20

30

40

50

60

70

0 4 8 12 16 20

Force [kN]


Deflection [mm]

Water- tightness

Prejudicialcracking


c < 0.5*Fc

s <

24

0 M

Pa

s <

15

0 M

Pa

s <

50

0 M

Pa

s <

30

0 M

Pa


24

b)

Flexural tests on composite beams with UHPFRC: a) without rebars, b) with rebars, Habel (2004).

a)

7. Structural response7. Structural response

NL: 10 cm

NL: 5 cm


25

Crack patterns at peak forcesCrack patterns at peak forces

UHPFRC without rebars UHPFRC with rebars (=2%)

Habel (2004)


26

Proposed geometries for Proposed geometries for rehabilitation - Habel, (2004)rehabilitation - Habel, (2004)

P: protection (hu=10 to 30 mm) PR: protection+ replacement of corroded rebars (hu=30 to 50 mm) R: protection + increase of load carrying capacity with rebars (hu>=50 mm)


27

8. Future works8. Future works

Structural response (ongoing)Structural response (ongoing)• Three types of composite members: walls, Three types of composite members: walls,

slabs and beams, to test the application of slabs and beams, to test the application of UHPFRC as protective or reinforcing layer.UHPFRC as protective or reinforcing layer.

• Three kinds of action effects: Effect of Three kinds of action effects: Effect of autogenous shrinkage at early age until 3 autogenous shrinkage at early age until 3 month, effect of sustained creep loads (3 to 9 month, effect of sustained creep loads (3 to 9 month), effect of fatigue loading (age: 3 month, month), effect of fatigue loading (age: 3 month, duration 1 month - 15 million cycles).duration 1 month - 15 million cycles).

• Main parameters: monolithic behaviour of the Main parameters: monolithic behaviour of the composite members and avoidance of composite members and avoidance of transverse cracking.transverse cracking.


28

Structural tests on composite Structural tests on composite beamsbeams


29

Structural tests on composite Structural tests on composite wallswalls


30

Structural tests on composite Structural tests on composite slabsslabs


31

• Application of UHPFRC for the Application of UHPFRC for the rehabilitation of the deck and curbs of a rehabilitation of the deck and curbs of a road bridge in Switzerland road bridge in Switzerland october october 2004.2004.

• Determination of the best surface Determination of the best surface treatment of UHPFRC at fresh test to treatment of UHPFRC at fresh test to guarantee adhesivity with bituminous guarantee adhesivity with bituminous concrete.concrete.

Pilot tests on sitePilot tests on site


32

Pilot tests on sitePilot tests on site


33

Sensitivity to a slopeSensitivity to a slope

Tolerance to 3 to 5 % slopes for current mixes


34

9. Expected benefits9. Expected benefits

«Targeted local hardening» of highway «Targeted local hardening» of highway structures, in most critical zones.structures, in most critical zones.

Simplification of the construction process.Simplification of the construction process. Reduction of the dead loads (superstructure Reduction of the dead loads (superstructure

and pavement).and pavement).

Increase of the performance of existing and Increase of the performance of existing and new structures (protection and reinforcement).new structures (protection and reinforcement).

Dramatic decrease of the number and severity Dramatic decrease of the number and severity of interventions during service life.of interventions during service life.


35

10. References10. References

1. Charron, J.P., Denarié, E. & Brühwiler, E.: Permeability of UHPFRC under high stresses. Proceedings, RILEM Symposium, Advances in Concrete Through Science and Engineering, March 22-24, 12 p., Chicago, USA, 2004.

2. Habel K.: Structural behaviour of composite “UHPFRC-concrete” elements, Doctoral thesis, Swiss Federal Institute of Technology, Lausanne, Switzerland, 2004, to be published.

3. Rossi P., Development of new cement composite material for construction, Proceedings of the International Conference on Innovations and Developments In Concrete Materials And Construction,, University of Dundee, Ed. by R. K. Dhir, P. C.Hewlett, L. J. Csetenyi, pp 17-29, Dundee, Scotland, September, 2002.

6.07.2004mid-term assessment london july 5-6 20041 wp 14 – high performance fiber reinforced...

Documents

compact hpfrcc materials

transport properties

long term behavior

rehabilitation wp leader

applicationmidterm ass

advantages of hpfrcc

objectives of wp

test methods