Maximum Shear Strength of RC Beams Retrofitted in Shear with FRP Composites
Publication: Journal of Composites for Construction
Volume 13, Issue 4
Abstract
In reinforced concrete (RC) beams strengthened in shear with fiber-reinforced polymer (FRP), crushing of the web can be a potential mode of failure. The guidelines provided by codes and standards for the design of structures strengthened with externally bonded FRP recommend limiting the maximum shear strength to avoid such an undesirable failure scenario. However, these limitation provisions are not based on specific research studies performed on beams strengthened in shear with FRP. Rather, they simply duplicate provisions used in conventional concrete codes and standards. The main objective of this research study is to assess the suitability of the limits specified by the guidelines, and propose, if necessary, an alternative equation as an upper limit for shear strength against web crushing failure in such structures. To this end, an analytical approach was developed based on the static theorem of the theory of plasticity. The predictions of the equations resulting from this approach were compared with those obtained from tests reported in the literature and with those predicted by ACI Committee 440-02, Canadian Standard S6-06, and the European recommendations fib TG 9.3. The study shows that the current ACI Committee 440-02 and Canadian Standards provisions are overly conservative and therefore need to be reviewed.
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Acknowledgments
The financial support of the National Science and Engineering Research Council of Canada (NSERC) and the Fonds québécois de la recherche sur la nature et les technologies (FQRNT) through operating grants are gratefully acknowledged.
References
American Concrete Institute (ACI). (1999). “Building code requirements for structural concrete.” ACI 318-99, Committee 318, ACI Farmington Hills, Mich.
American Concrete Institute (ACI). (2002). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440 2R-02, ACI Committee 440, Farmington Hills, Mich.
American Concrete Institute, (ACI). Committee 318. (2005). “Building code requirements for structural concrete.” ACI 318-05, Farmington Hills, Mich.
ASCE-ACI Task Committee 426. (1973). “The shear strength of reinforced concrete members.” ASCE J. Struct. Div., 99(6), 1091–1187.
Bousselham, A., and Chaallal, O. (2006a). “Behavior of RC T-beams strengthened in shear with CFRP: An experimental study.” ACI Struct. J., 103(3), 339–347.
Bousselham, A., and Chaallal, O. (2006b). “Effect of transverse steel and shear span on the performance of RC beams strengthened in shear with CFRP.” Composites, Part B, 37(1), 37–46.
Bousselham, A. and Chaallal, O. (2008). “Mechanisms of shear resistance of concrete beams strengthened in shear with externally bonded FRP.” J. Compos. Constr., 12(5), 499–512.
Canadian Standards Association (CSA). (2004). “Design of concrete structures for buildings.” CSA A23.3-04, Rexdale, Ont., Canada.
Canadian Standards Association (CSA). (2006). “Canadian highway bridge design code.” CSA-S6-06, Rexdale, Ont., Canada.
Carolin, A., and Taljsten, B. (2005). “Experimental study of strengthening for increased shear bearing capacity.” J. Compos. Constr., 9(6), 488–496.
Chaallal, O., Shahawy, M., and Hassan, M. (2002). “Performance of reinforced concrete T-girders strengthened in shear with CFRP fabrics.” ACI Struct. J., 99(3), 335–343.
Chajes, M. J., Januszka, T. F., Mertz, D. R., Thomson, T. A., and Finch, W. W. (1995). “Shear strengthening of reinforced concrete beams using externally applied composites fabrics.” ACI Struct. J., 92(3), 295–303.
Colotti, V., Spadea, G., and Swamy, R. N. (2004). “Analytical model to evaluate failure behavior of plated reinforced concrete beams strengthened for shear.” ACI Struct. J., 101(6), 755–764.
Comité Euro-International du Béton (CEB). (1992). “Design of concrete structures. Part 1-1: General rules and rules for buildings.” Eurocode No. 2, Lausanne, Switzerland.
Diagana, C., Li, A., Gedalia, B., and Delmas, Y. (2003). “Shear strengthening effectiveness with CFRP strips.” Eng. Struct., 25(4), 507–516.
Fédération Internationale du Béton (FIB). (2001). “Externally bonded FRP reinforcement for RC structures.” Bulletin 14, Lausanne, Switzerland.
Funakawa, I., Shimono, K., Watanabe, T., Asada, S., and Ushijima, S. (1997). “Experimental study on shear strengthening with continuous fiber reinforcement sheet and methyl methacrylate resin.” Proc., 3rd Int. Symp. on Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, Sapporo, Japan, 491–498.
Hsu, C.-T. T., Punurai, W., and Zhang, Z. (2003). “Flexural and shear strengthening of RC beams using carbon fiber reinforced polymer laminates.” ACI Special Publications, 211, 89–114.
Kamiharako, A., Maruyama, K., Takada, K., and Shiomura, T. (1997). “Evaluation of shear contribution of FRP sheets attached to concrete beams.” Proc., 3rd Int. Symp. on Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, Sapporo, Japan, 467–474.
Khalifa, A., Gold, W. J., Nanni, A., and Abdelaziz, M. I. (1998). “Contribution of externally bonded FRP to shear capacity of flexural members.” J. Compos. Constr., 2(4), 195–203.
Kuchma, D. A., and Kim, K. S. (2001). “Stress limits and minimum reinforcement requirements in shear design provisions.” Prog. Struct. Eng. Mater., 3(4), 317–325.
Li, A., Diagana, C., and Delmas, Y. (2002). “Shear strengthening effect by bonded composite fabrics on RC beams.” Composites, Part B, 33(3), 225–239.
Matthys, S., and Triantafillou, T. (2001). “Shear and torsion strenthening witn externally bonded FRP reinforcement.” Proc., Int. Workshop on Composites in Construction: A Reality, E. Cosensa, G. Manfredi, and A. Nanni, eds., ASCE, Reston, Va., 203–210.
Nielsen, M. P. (1984). Limit analysis and concrete plasticity, Prentice–Hall, Englewood Cliffs, N.J.
Nielsen, M. P. (1999). Limit analysis and concrete plasticity, CRC Press, New York.
Regan, P. E., (1993). “Research on shear: A benefit to humanity or a waste of time?” Struct. Eng., 71(25), 337–347.
Taerwe, L., Khalil, H., and Matthys, S. (1997). “Behaviour of RC beams strengthened in shear by external CFRP sheets.” Proc., 3rd Int. Symp. on Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, Sapporo, Japan, 507–514.
Täljsten, B. (1997). “Strengthening of concrete structures for shear with bonded CFRP-fabrics.” Proc., U.S.–Canada-Europe Workshop on Bridge Engineering, U. Meir and R. M. Betti, eds., EMPA, Zurich, Switzerland, 57–64.
Täljsten, B. (2003). “Strengthening of concrete beams for shear with CFRP sheets.” Constr. Build. Mater., 17(1), 15–26.
Triantafillou, T. C., and Antonopoulos, C. P. (2000). “Design of concrete flexural members strengthened in shear with FRP.” J. Compos. Constr., 4(4), 198–205.
Uji, K. (1992). “Improving shear capacity of existing reinforced concrete members by applying carbon fiber sheets.” Trans. Jpn. Concr. Inst., 14, 253–266.
Umezu, K., Fujita, M., Nakai, H., and Tamaki, K. (1997). “Shear behaviour of RC beams with aramid fiber sheet.” Proc., 3rd Int. Sym. on Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, Japan Concrete Institute, Sapporo, Japan, 491–498.
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Information
Published In
Journal of Composites for Construction
Volume 13 • Issue 4 • August 2009
Pages: 302 - 314
Copyright
© 2009 ASCE.
History
Received: Jan 29, 2008
Accepted: Jan 15, 2009
Published online: Jul 15, 2009
Published in print: Aug 2009
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