THE USE OF FRP AS EMBEDDED REINFORCEMENT …ci.group.shef.ac.uk/CI_content/FRP/PW_2004.pdfTHE USE OF...
Transcript of THE USE OF FRP AS EMBEDDED REINFORCEMENT …ci.group.shef.ac.uk/CI_content/FRP/PW_2004.pdfTHE USE OF...
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
THE USE OF FRP ASEMBEDDED REINFORCEMENT
IN CONCRETE
Peter Waldron
Centre for Cement and ConcreteUniversity of Sheffield, Sheffield, S1 3JD, UK
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Advanced Composites (Applications)
- High Strength- Light Weight- Exceptional Durability
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Composites in Civil Engineering: Why?
Non Magnetic
App
licat
ions
Durability
High Strength
Durability
Strengthening and
Rehabilitation
ACI 440ISIS Canada
fib TG 9.3IStructENGCC
JSCE
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Composites in Civil Engineering: Why?
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Composites in Civil Engineering: Why?
Chloride PenetrationChloride Penetration
0.0000
0.1000
0.2000
0.3000
0.4000
0.5000
0.6000
0.7000
12 25 37.5 50 75
Depth (mm)
Chl
orid
e %
of C
oncr
ete
5 Years10 Years20 Years30 Years40 Years50 Years
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Composites in Civil Engineering: Why?
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Applications: Durability
Slope reinforcement
Reinforcement for tunnels
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Applications: Durability
Fender - Qatar
Creek Bridge - Sierrita de la Cruz (USA)
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Applications: Electromagnetic Neutrality
Maglev train - Japan
Precast post and panel fencingHemel Hempstead (UK)
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Applications: High Strength
Birdie Bridge - Ibaragi Prefecture, Japan
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
FRP RC Bridges – Worldwide Growth
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004Estimated Market Size: 85 M TonnesEstimated Market Size: 3.5 M Tonnes
Consumption of Steel Reinforcing Bars
Worldwide Consumption ofSteel Reinforcing Bars
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Reinforced Composites in the Construction Market
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Composites in Civil Engineering: Why not?
•Higher raw material cost
•Lower stiffness
•Lack of ductility
CONFIDENCE
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
FRP RC and Code Development
19871991
1993
1995
1997
1999
2001
1992
1994
1996
1998
2000
20022003
2004
JSCE Committe on CFRM, CSCE technical Committee
CSCE Report, ACI 440, BRITE-EURAM Project
JSCE State-of-the-Art Report
EUROCRETE Project
Design Recommendations- JSCE- EUROCRETE
ConFibreCrete Network
CSCE Design Recommendations
IstructE Design RecommendationSwedish National code
fib Bulletin 14, ISIS Manuals, ACI 440.1R
ACI 440.2R, CUR Recommendations
ACI 440.1R (revised)
fib TG 9.3
Concrete Society - TR55, fib bulletin 10
CurvedNFR
Concrete Society - TR55 (revised)
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
RECOMMENDATION FORDESIGN AND CONSTRUCTIONOF CONCRETE STRUCTURESUSING CONTINUOUS FIBER
REINFORCINGMATERIALS
CONCRETE ENGINEERING SERIES
FRP RC and Code Development
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Flexure and Cracking
Punching Shear
Shear
Bond
Design Philosophy Plate Bonding
Column Confinement
RC
EBR
Shear Strengthening
Research on FRP at Sheffield
Curved-NFR
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
•Different behaviour
•Existing design codes are based on the use of steel reinforcement
•Existing design equations need to be re-examined
•New design philosophy
Steel RC vs FRP RC
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
FRP RC Steel RC
Structural Considerations: Flexure
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Structural Considerations: Flexure
Ductility? Deformability?
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Structural Considerations: Flexure
b
FRP
Strain
ε cu
x = ξ d
2%
d
b
d
0.5%
Stress
σε
fcu
Steel
)4.01(68.0 2 ξξ −≈ cdSd fbdM
cuf
cdreqf E
fεξ
ξρ⋅−
≈168.0 2
,
Bending moment capacity of therectangular FRP RC section:
Required FRP reinforcement ratio:
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Structural Considerations: Flexure
Modes of failure: Concrete CrushingRupture of FRP Reinforcement
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
0
20
40
60
80
100
120
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Loa
d (k
N)
Crack width (mm)
Calculated widthCalculated strain
Calculated widthMeasured strain
Measured width
Structural Considerations: Cracking
For good bond, existing strain based equations can be used
BS8110 equations are non-conservative
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
V = Vc + VsV = Vc + VsConcrete
contributionEmpirical equation models
- concrete in compression- aggregate interlock- dowel action
Contribution of shear r/ment+
Truss analogy theory
Shear Design
Limiting Strain = 0.2% - 0.25%
V = Vc + VsV = Vc + Vs
•Similar shear mechanisms?
•Sum of contributions?
•Limiting strain concept?
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Shear Design
Shear of FRP RC Beams
Punching Shear of FRP RC slabs
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Limiting Strain = 0.45%
V = Vc + VsV = Vc + VsShear Design
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
•Pull-out Cube tests:4 phases, more than 130 specimens
•Beam tests:4 phases, more than 37 beams9 of them designed to fail in bond
•International Round Robin TestsPull-out + Splitting
767 767766
250
Single bar anchorage:
L
Bond of FRP Bars in Concrete
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Concrete
Failure interface in resin
Bar fibers
Bar resin Failure interface in concrete
Concrete
FRP Bar
Embedment length
Pull-out direction
Wedging effect
Bond of FRP Bars in Concrete
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Bond of FRP Bars in Concrete
•GFRP bars splitting bond strength around 65 -70% of CFRP bars
•Possible Reason ?
•Difference in Young’s Modulus ⇒ Difference in angle a
CFRP bar
Microcracksα
Fb
Fsp
GFRP bar
αFb
Fsp
ds
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Shaping The Future of FRPs: Curved Non-Ferrous R/ment
Longitudinal direction
Transverse direction
•State of stress
•Reinforcement geometry
•Constituent materials
•Manufacturing processes
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
15
32
15050450
60
250
60 60130
38
5085
50
Shaping The Future of FRPs: Curved Non-Ferrous R/ment
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
•Reinforced concrete memorial bases
Shaping The Future of FRPs: Curved Non-Ferrous R/ment
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
0%
1%
2%
3%
4%
0 100 200 300Resistance-Capacity, kN
Applied LoadBondShearFlexure
Rel
ativ
e Fr
eque
ncy
Design Philosophy
Resistance R
Load E
ffect
S
PS,
R (
S,R
)
S = R∴Limit State
S < R∴ Safe
S > R∴ Failure
Resistance R
Load E
ffect
S
PS,
R (
S,R
)
S = R∴Limit State
S = R∴Limit State
S < R∴ Safe
S > R∴ Failure
S > R∴ Failure
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
Structural reliability assessment:Monte Carlo Simulation method
with Latin Hypercube andConditional Expectation
variance reductiontechniques
Resistance R
Load E
ffect
S
PS,
R (
S,R
)
S = R∴ Limit State
S < R∴ Safe
S > R∴ Failure
Resistance R
Load E
ffect
S
PS,
R (
S,R
)
S = R∴ Limit State
S = R∴ Limit State
S < R∴ Safe
S > R∴ Failure
S > R∴ Failure
Design Philosophy: Assessment Methodology
The Second International Conference on FRP Composites in Civil Engineering 8-10 December 2004 - Adelaide, Australia CICE 2004
• Conventional fundamental RC principles can be used for design
• Basic design guidelines exist• Different philosophy should be adopted to address the issue of safety
• Advanced guidelines soon to come• There are challenges with all new material technologies
• New structural concepts can be developed• Exciting time for Civil Engineering
Conclusions