Effect of beam size and FRP thickness on interfacial shear stress concentration and failure mode of FRP-strengthened beams

Abstract

The strengthening of reinforced concrete (RC) structures using externally-bonded fibre reinforced polymer (FRP) is becoming increasingly popular. An important issue related to the strengthening of beams using FRP is the potential brittle failures attributed to the interfacial stress concentrations at FRP-cut off points and at flexural cracks along the beam. In the present studies, three series of tests were conducted to investigate the interfacial shear stress concentration at the FRP cut-off regions as well as the failure mode of FRP-strengthened beams as a function of beam size and FRP thickness. The test results were compared with theoretical and numerical predictions. Additionally, the performance of FRP-strengthened beams incorporating Engineered Cementitious Composites (ECC) was also investigated.