Experimental investigation of the performance of diagonal reinforcement and CFRP strengthened RC short columns

Abstract

In this study, quasi-static seismic performances of CFRP wrapped and diagonal reinforcement reinforced concrete (RC) short columns are presented. RC short columns have been tested experimentally under constant axial load and cyclic lateral load. In the scope of this study, the performance of eighteen RC short columns, which consist of six CFRP wrapped, six diagonal reinforcement and six reference (Ref) columns, have been examined. Ref columns are the perfect columns produced in accordance with the regulation requirements. Therefore, it is aimed to examine the proposed diagonal rebar and CFRP applications as an alternative to the design in the earthquake regulations. The use of Ø10 and Ø12 reinforcements as a shear reinforcement for Ref columns and columns with diagonal reinforcement has also been examined for the contribution of the diameter of shear reinforcement to performance. Besides the difference in the diameters of the shear reinforcement and the applied methods, the aspect ratio (αs) is another parameter. Eighteen test columns were divided into three series and tested with αs = 2, 1.5 and 1 aspect ratio in order to examine the effectiveness of the applied methods by increasing the effect of shear dominant behaviour. The experimental results showed that columns with diagonal reinforcement and CFRP wrapped columns succeeded in exceeding the performances of perfect Ref columns and could be an alternative to the existing design.