Effect of reinforcement ratio on flexural behavior of reinforced concrete beams strengthened with CFRP plates

Abstract

An experimental study was carried out to investigate the effect of tensile reinforcement ratio on the flexural capacity of reinforced concrete beams strengthened with Carbon Fiber Reinforced Polymer (CFRP) plates. This study aims to observe the effect of reinforcement ratio on debonding failure load of reinforced concrete beams externally strengthened with CFRP plates. Six reinforced concrete beams consisting of three control beams and three beams strengthened with CFRP plates were tested. The beams were simply supported and loaded with four-point bending. The test variable was tensile reinforcement ratio (1%, 1.5%, and 2.5%). CFRP plates were glued on the bottom of the beams with the purpose to increase the flexural strength of the beams. Analytical prediction using fiber element method was also carried out to obtain a full flexural response of the beams due to bending load. The test results show that beams with CFRP plates have higher flexural capacity for about 10% to 50% than the control beams. However, at a specified load level, two of beams with CFRP plates suddenly collapse due to delamination of CFRP plates. In addition, analytical calculation predicts well the test results in excellent accuracy.