Flexural Response of Reinforced Concrete Beams Strengthened with End-Anchored Partially Bonded Carbon Fiber-Reinforced Polymer Strips
Publication: Journal of Composites for Construction
Volume 9, Issue 2
Abstract
This paper presents the results of experimental and analytical studies carried out to investigate the flexural behavior of reinforced concrete beams strengthened with end-anchored partially bonded carbon fiber-reinforced polymer (CFRP) strips. A total of six beams, each 2400 mm long, 150 mm wide, and 250 mm deep with a tension steel reinforcement ratio of 1.18%, were tested. One beam was left unstrengthened as the control, another beam was strengthened with a fully bonded CFRP strip, and the remaining four beams were strengthened with partially bonded CFRP strips placed on the tension face of the beam and fixed at both ends using a mechanical anchor. The influence of varying the CFRP unbonded length (250 mm, 750 mm, 2×500 mm, and 1,250 mm) on the beam flexural response was studied. The experimental results revealed that end-anchored partially bonded CFRP strips significantly enhanced the ultimate capacity of the control beam and performed better than the fully bonded strip with no end-anchorage. This observation stresses the importance of end-anchorage in such strengthening schemes, especially considering that the end-anchored partially bonded CFRP strengthened beams showed similar flexural behavior trends. Finally, an inelastic section analysis procedure that takes into consideration the incompatibility of strains was developed to verify the obtained test results. The analysis produced good predictions of the experimental results in terms of the moment-curvature response and showed the effect of CFRP unbonded length on the strain of the internal tension steel.
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Acknowledgments
This research was conducted with the financial assistance of the Natural Sciences and Engineering Research Council of Canada (NSERC). The Sika CarboDur CFRP repair system was graciously donated by Sika Canada. Thanks are extended to A. Lawrence, M. Badawi, T. Ridgeway, K. Bowman, and R. Sherping for their assistance during various stages of the work.
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Information
Published In
Journal of Composites for Construction
Volume 9 • Issue 2 • April 2005
Pages: 170 - 177
Copyright
© 2005 ASCE.
History
Received: Nov 10, 2003
Accepted: Jun 30, 2004
Published online: Apr 1, 2005
Published in print: Apr 2005
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