External Prestressed Carbon Fiber-Reinforced Polymer Straps for Shear Enhancement of Concrete
Publication: Journal of Composites for Construction
Volume 6, Issue 4
Abstract
The use of fiber-reinforced polymers (FRPs) for the strengthening and repair of existing concrete structures is a field with tremendous potential. The materials are very durable and, hence, ideally suited for use as external reinforcement. Although extensive work has been carried out investigating the use of FRPs for flexural strengthening, a fairly recent development is the use of these materials for the shear strength enhancement of concrete. The current system investigates the use of posttensioned, nonlaminated, carbon fiber-reinforced polymer (CFRP) straps as external shear reinforcement for concrete. Experiments were carried out on an unstrengthened control beam and beams strengthened with external CFRP straps. It was found that the ultimate load capacity of the strengthened beams was significantly higher than that of the control specimen. Existing design codes and analysis methods were found to underestimate the ultimate resistance of the control specimen and the strengthened beams. Nevertheless, the modified compression field theory provided insight into possible failure mechanisms and the influence of the strap prestress level on the structural behavior. It is concluded that the use of these novel stressed elements could represent a viable and durable means of strengthening existing concrete infrastructure.
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References
American Concrete Institute (ACI). (1998). “Building code requirements for structural concrete,” ACI, 318-95, ACI 318R-95, Detroit.
British Department of Transport. (1995). The assessment of concrete highway bridges and structures, BD44/95, British Department of Transport, U.K., 3(4) Part 14, Appendix A.
Chajes, M. J., Januszka, T. F., Mertz, D. R., Thomson, T. A., and Finch, W. W.(1995). “Shear strengthening of reinforced concrete beams using external composite fabrics.” ACI Struct. J., 92(3), 295–303.
Clarke, J., and Waldron, P.(1996). “The reinforcement of concrete structures with advanced composites.” Struct. Eng., The Institution of Structural Engineers, London, UK, 74(17), 283–288.
Collins, M. P., Mitchell, D., Adebar, P., and Vecchio, F. J.(1996). “A general shear design method.” ACI Struct. J., 93(1), 36–45.
Czaderski, C. (1998). “Shear strengthening with CFRP L-shaped plates.” Schweizer Ingenieur und Architekt, 43 Switzerland.
Drimoussis, E. H., and Cheng, J. J. R. (1994). “Shear strengthening of concrete girders using carbon fiber reinforced plastic sheets.” Structural Engineering Report No. 205, Univ. of Alberta, Alberta Canada.
Eurocode 2 (1992). “Design of concrete structures, part 1: General rules and rules for buildings.” DD ENV 1992-1-1, British Standards Institution, London, U.K.
Fenwick, R. C., and Paulay, T.(1968). “Mechanisms of shear resistance of concrete beams.” J. Struct. Div., 94(10), 2235–2350.
Kotsovos, M. D.(1983). “Mechanisms of ‘shear’ failure.” Mag. Concrete Res., 35(123), 99–106.
Kotsovos, M. D.(1988). “Compressive force path concept: Basis for reinforced concrete ultimate limit state design.” ACI Struct. J., 85(1), 68–75.
Täljsten, B. (1994). “Plate bonding-strengthening of existing concrete structures with epoxy bonded plates of steel or fiber reinforced plastics.” PhD thesis, Luleå Univ. of Technology, Luleå, Sweden.
The Institution of Structural Engineers. (1999). Interim guidance on the design of reinforced concrete structures using fiber composite reinforcement. The Institution of Structural Engineers, London.
Triantifillou, T. C. (1997). “Shear strengthening of concrete members using composites. Non-metallic (FRP) reinforcement for concrete structures.” Proc., 3rd Int. Symposium, Japan Concrete Institute, Japan, 1, 523–530.
Uji, K. (1992). “Improving shear capacity of existing reinforced concrete members by applying carbon fiber sheets.” Trans. Jpn. Concrete Institute, Tokyo, (14), 253–266.
Vecchio, F. J., and Collins, M. P.(1986). “The modified compression field theory for reinforced concrete elements subjected to shear.” J. Am. Concr. Instr., 83(2), 216–231.
Winistörfer, A. U. (1999). “Development of non-laminated advanced composite straps for civil engineering applications.” PhD thesis, Univ. of Warwick, U.K.
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Information
Published In
Journal of Composites for Construction
Volume 6 • Issue 4 • November 2002
Pages: 249 - 256
Copyright
Copyright © 2002 American Society of Civil Engineers.
History
Received: Oct 13, 2000
Accepted: May 1, 2001
Published online: Oct 15, 2002
Published in print: Nov 2002
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