Nonlinear 2D Finite-Element Modeling of RC Beams Strengthened with Prestressed NSM CFRP Reinforcement
Publication: Journal of Composites for Construction
Volume 20, Issue 4
Abstract
This paper presents a comprehensive two-dimensional (2D) nonlinear finite-element (FE) analysis of reinforced concrete (RC) beams strengthened with prestressed or non-prestressed near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP) reinforcement. In this model, the bond-slip relationship between the steel reinforcement and surrounding concrete as well as that between the NSM CFRP reinforcement and concrete substrate are precisely modeled with cohesive interface elements. Based on the smeared crack approach, the tensile and shear behavior for concrete cracking are considered using appropriate models. The prestressing effect was enforced in the NSM CFRP reinforcement using the equivalent temperature method, and the anchoring effect of U-shaped steel end anchors on the NSM CFRP reinforcement is properly implemented in the model. Moreover, the radial stresses induced by the tensile steel bars on the surrounding concrete are properly considered, and the bar-end concrete cover separation failure mode is successfully captured. Comparisons between the numerical and experimental results confirm that the proposed FE method is appropriate for predicting the load-deflection curves, failure modes, and cracking patterns of the strengthened beams. Based on this study, the 2D FE model is utilized to conduct a parametric study and can be used to aid in realistic structural applications and optimization of the use of prestressed/non-prestressed NSM reinforcement for strengthening RC beams.
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Acknowledgments
The authors would like to acknowledge financial support from the National Basic Research Program of China (973 Program) (No. 2012CB026200), the Natural Science Foundation of Jiangsu Province, China (No. BK2012023), the National High Technology Research and Development Program of China (No. 2012AA03A204), and the International Science and Technology Cooperation of Program of China (No. 2012DFG20510). The authors also wish to thank Tian-Sheng Shi in Hong Kong University of Science and Technology for his help in acquiring MSC.MARC software.
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© 2016 American Society of Civil Engineers.
History
Received: Feb 22, 2015
Accepted: Oct 22, 2015
Published online: Jan 13, 2016
Discussion open until: Jun 13, 2016
Published in print: Aug 1, 2016
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