Behavior of Circular Concrete Members Reinforced with Carbon-FRP Bars and Spirals under Shear
Publication: Journal of Composites for Construction
Volume 21, Issue 2
Abstract
Considerable research in recent years has exclusively considered concrete members with rectangular cross sections in developing fiber-reinforced polymer (FRP) shear design provisions. Although there is no evidence that these provisions do not apply equally well to nonrectangular sections, the behavior of circular sections has yet to be confirmed with experimental results. This paper reports experimental data about the shear strength of circular concrete beams reinforced with carbon-FRP (CFRP) bars and spirals. A total of five full-scale concrete beams with a total length of 3,000 mm and diameter of 500 mm were constructed and tested up to failure. The test parameters included the type of reinforcement (CFRP versus steel) and the ratio of shear reinforcement (spiral spacing). The investigation revealed that the beams reinforced with CFRP bars and spirals exhibited high load-carrying capacity and performance comparable with that of the control beam reinforced with steel. The experimental shear strengths of the CFRP-reinforced concrete beams were compared with theoretical predictions provided by current codes and design guidelines. The comparison indicated that some of the available design methods provide reasonable predictions. However, a more precise formula for the shear strength was proposed to account for the mechanical properties and geometry of CFRP spirals. The proposed equation provided more reasonably accurate and conservative predictions.
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Acknowledgments
The authors would like to express their gratitude to the Natural Science and Engineering Research Council of Canada (NSERC); Canada Research Chair in Advanced Composite Materials for Civil structures; the Fonds de la Recherche du Quebec—Nature et Technologie (FRQ-NT); and the Ministère de l’Économie, de l’Innovation et des Exportations (MEIE) of Quebec for their financial support and Pultrall (2012) (Thetford Mines, Quebec) for the donation of the CFRP materials. They are also grateful to the technical staff of the Canadian Foundation for Innovation (FCI) structural laboratory at the Department of Civil Engineering of the University of Sherbrooke.
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Published In
Journal of Composites for Construction
Volume 21 • Issue 2 • April 2017
Copyright
©2016 American Society of Civil Engineers.
History
Received: Feb 1, 2016
Accepted: Jul 5, 2016
Published online: Aug 17, 2016
Discussion open until: Jan 17, 2017
Published in print: Apr 1, 2017
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