The Experimental Study of RC Beams with Shear Reinforcement Strengthened with CFRP

• Main Authors: Chih-Ching Cheng, 鄭志勤
• Other Authors: Chih-Tsung Lin
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/qe6y2x

碩士 === 國立臺北科技大學 === 土木與防災研究所 === 98 === The shear strength of RC Beams is mainly composed of Vc, the shear mechanism of concrete and rebars, and Vs, the shear mechanism of shear reinforcement. Vc plus Vs would be the full shear strength of RC Beams. Furthermore, when coupling with Vp, the shear mechanism of shear retrofitted by CFRP, the behaviors under the interactions among Vc, Vs, and Vp are more complex and uneasy to predict. Common limitaions often occur in most of previous studies of shear retrofitted by CFRP, which leads to impact the preciseness of the prediction of the shear strength. In addition, empirical formulas in practical applications of RC Beams still seem fuzzy and full of uncertainty. Therefore, it''s necessary to analyze the design of Vc, Vs, and Vp. The purpose and scope of this research is, first of all, to review the existing codes against the shear performance of RC beams with experiments; secondly, to study the relationship between CFRP and the shear strength of RC beams under different shear reinforcement spacings, and then to review the retrofitted bebefit and stiffness change; finally, to review the existing codes and the empirical formulas based on the experimental data, and then to provide comparative results to designers. The test results indicated that the designs of ACI code（by Vc＝simplified formula and exact formula）are indeed more conservative. Based on the analysis of shear retrofitted by CFRP, it has been proven that shear retrofitted by CFRP can indeed increase the shear strength and the stiffness of RC beams; however, with the increasing amounts of shear reinforcement, retrofitted benefit would be negatively impacted accordingly. In addition, greater retrofitted benefit can be achieved when the shear reinforcement spacing is greater than 1/2d; on the other hand, retrofitted benefit would be limited when the shear reinforcement spacing is less than or equal to 1/2d, which may result from the size of specimens.