Slenderness Effects on Circular CFRP Confined Reinforced Concrete Columns
Publication: Journal of Composites for Construction
Volume 14, Issue 3
Abstract
External bonding of circumferential fiber-reinforced polymer (FRP) wraps is a widely accepted technique to strengthen circular RC columns. To date, most of the tests performed on FRP strengthened columns have considered short, unreinforced, small-scale concrete cylinders, with height-to-diameter ratios of less than three, tested under concentric, monotonic, and axial load. In practice, most RC columns have height-to-diameter ratios considerably larger than three and are subjected to loads with at least minimal eccentricity. Results of an experimental program performed to study the effects of slenderness on carbon FRP (CFRP) wrapped circular RC columns under eccentric axial loads are presented. It is shown that CFRP wraps increase the strength and deformation capacity of slender columns, although the beneficial confining effects are proportionally greater for short columns, and that theoretical axial-flexural interaction diagrams developed using conventional sectional analysis (but incorporating a simple FRP confined concrete stress-strain model) provide conservative predictions for nonslender CFRP wrapped columns under eccentric loads. The use of longitudinal CFRP wraps to reduce lateral deflections and allow slender columns to achieve higher strengths, similar to otherwise identical nonslender columns, is also demonstrated.
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Acknowledgments
The writers are members of the Intelligent Sensing for Innovative Structures Network and acknowledge the support of the Canadian Networks of Centres of Excellence Program and the Natural Sciences and Engineering Research Council of Canada.
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© 2010 ASCE.
History
Received: Apr 19, 2009
Accepted: Sep 3, 2009
Published online: Feb 3, 2010
Published in print: Jun 2010
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