Shear Strengthening of RC Beams with Externally Bonded FRP Composites: Effect of Strip-Width-to-Strip-Spacing Ratio
Publication: Journal of Composites for Construction
Volume 15, Issue 5
Abstract
The results of an experimental and analytical investigation of shear strengthening of reinforced concrete (RC) beams with externally bonded (EB) fiber-reinforced polymer (FRP) strips and sheets are presented, with emphasis on the effect of the strip-width-to-strip-spacing ratio on the contribution of FRP (). In all, 14 tests were performed on 4,520-mm-long -beams. RC beams strengthened in shear using carbon FRP (CFRP) strips with different width-to-spacing ratios were considered, and their performance was investigated. In addition, these results are compared with those obtained for RC beams strengthened with various numbers of layers of continuous CFRP sheet. Moreover, various existing equations that express the effect of FRP strip width and concrete-member width and that have been proposed based on single or double FRP-to-concrete direct pullout tests are checked for RC beams strengthened in shear with CFRP strips. The objectives of this study are to investigate the following: (1) the effectiveness of EB discontinuous FRP sheets (FRP strips) compared with that of EB continuous FRP sheets; (2) the optimum strip-width-to-strip-spacing ratio for FRP (i.e., the optimum FRP rigidity); (3) the effect of FRP strip location with respect to internal transverse-steel location; (4) the effect of FRP strip width; and (5) the effect of internal transverse-steel reinforcement on the CFRP shear contribution.
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Acknowledgments
The financial support of the National Science and Engineering Research Council of Canada (NSERC)NSERC, the Fonds québécois de la recherche sur la nature et les technologies (FQRNT), and the Ministère des Transports du Québec (MTQ) through operating grants is gratefully acknowledged. The efficient collaboration of John Lescelleur (senior technician) and Juan Mauricio Rios (technician) at ÉTS, in conducting the tests, is acknowledged.
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Published In
Journal of Composites for Construction
Volume 15 • Issue 5 • October 2011
Pages: 732 - 742
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Jul 13, 2010
Accepted: Mar 24, 2011
Published online: Mar 26, 2011
Published in print: Oct 1, 2011
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