Strengthening of Short Shear Span Reinforced Concrete T Joists with Fiber-Reinforced Plasic Composites
Publication: Journal of Composites for Construction
Volume 6, Issue 4
Abstract
In this work, the results of an experimental study conducted in a 1964-vintage building are presented. Twelve reinforced concrete (RC) T-joists strengthened with fiber-reinforced plastic (FRP) composites were loaded until failure in a short shear span configuration. Different strengthening schemes, including different FRP materials and a new FRP anchorage system, were adopted in order to compare the performance of the different installations. Carbon FRP and aramid FRP sheets in an epoxy matrix were bonded to the RC joists using the wet layup technique. All of the joists were loaded close to one end support and showed similar cracking patterns at failure. The design calculations were based on experimental results. All of the unanchored FRP strengthened beams showed failure due to peeling, while the anchored FRP strengthened members showed failure due to anchor pullout at higher load values. It was found that an increase in the amount of FRP did not result in a proportional increase in the shear capacity, as expected by design equations, but all of the beams showed a considerable increase in stiffness. The experimental results are compared with the results expected by analytical models in order to discuss the structural behavior of FRP strengthened beams tested in a real building with a short shear span. It was found that theoretical calculations resulted in nonconservative results for the tested specimens.
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References
American Concrete Institute (ACI). (2000). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440 draft, Externally bonded FRP systems for strengthening concrete structures, Detroit, 54–58.
Gendron, G., Picard, A., and Guerin, M. C.(1999). “A theoretical study on shear of reinforced concrete beams using composite plates.” Compos. Struct., 45(4), 303–309.
Khalifa, A., Gold, W., Nanni, A., and Abdel Aziz, M. I.(1998). “Contribution of externally bonded FRP to shear capacity of RC flexural members.” J. Compos. Constr., 2(4), 195–202.
Khalifa, A., and Nanni, A.(2000). “Improving shear capacity of existing RC-T section beams using FRP composites.” Cem. Concr. Compos., 22(2), 165–174.
Khalifa, A., Tumialan, G., Nanni, A., and Belarbi, A. (1999). “Shear strengthening of continuous RC beams using externally bonded CFRP sheets.” Fiber reinforced polymer reinforcement for reinforced concrete structures, Proc., 4th Int. Symp., American Concrete Institute, Detroit, 995–1008.
Kim, D., Kim, W., and White, R. N.(1999). “Arch action in reinforced concrete beams—A rational prediction of shear strength.” ACI Struct. J., 96(4), 586–593.
Maeda, T., Asano, Y., Sato, Y., Ueda, T., and Kakuta, Y. (1997). “A study on bond mechanism of carbon fiber sheet.” Proc., 3rd Symp. on Non Metallic (FRP) Reinforcement for Concrete Structures, Vol. 1, 279–286.
“MBrace—Composite strengthening system.” (1998). Engineering design guidelines, 2nd Ed., Master Builders Inc., Cleveland, 3-3–3-6.
Mettemeyer, M. (1999). “In situ rapid load testing of concrete structures.” MSc thesis, Dept. of Civil Engineering, Univ. of Missouri—Rolla, Rolla, Mo.
Miller, B. D. (1999). “Bond between CFRP sheets and concrete.” MSc thesis, Dept. of Civil Engineering, Univ. of Missouri—Rolla, Rolla, Mo.
Nanni, A. (1997). “A behavior of simply supported and continuous RC-beams strengthened with carbon FRP sheets.” 2nd Symp. on Practical Solutions for Bridge Rehabilitation, BASAR II, Univ. of Missouri at Kansas City, Kansas City, Mo., 261–270.
Raghu, H. A. (2000). “Shear performance of RC beams strengthened in-situ with composites.” MSc thesis, Dept. of Civil Engineering, Univ. of Missouri—Rolla, Rolla, Mo.
Triantafillou, T. C.(1998). “Shear strengthening of reinforced concrete beams using epoxy-bonded FRP composites.” ACI Struct. J., 95(2), 107–115.
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.
Triantafillou, T. C., and Plevris, N.(1992). “Strengthening of R/C beams with epoxy-bonded fiber-composite materials.” Mater. Struct., 25, 201–211.
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Information
Published In
Journal of Composites for Construction
Volume 6 • Issue 4 • November 2002
Pages: 264 - 271
Copyright
Copyright © 2002 American Society of Civil Engineers.
History
Received: Jan 12, 2001
Accepted: Apr 22, 2002
Published online: Oct 15, 2002
Published in print: Nov 2002
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