FRP COMPOSITES FOR SHEAR STRENGTHENING OF RC BEAMS

Fiber Reinforced Polymer (FRP) composite systems can be used for shear strengthening of reinforced concrete (RC) members. The present study investigated the shear performance and the modes of failure of simply supported RC T-beams externally strengthened in shear with FRP composites. Two different FRP-based strengthening systems were investigated, namely, externally bonded FRP sheets and Near Surface Mounted (NSM) FRP rods. The latter is a novel technique on which no literature is available to date. The experimental program consisted of testing eleven full-scale, T beams. The beams were grouped into three series. The first series was tested to investigate the influence on the shear capacity of the concrete surface roughness and of the carbon FRP sheets axial rigidity. The second series focused on the capability of externally bonded CFRP reinforcement to enhance the ultimate capacity of beams that already have adequate internal steel reinforcement. In addition, a beam with internal glass FRP stirrups was tested in this series. In the third series, the novel shear strengthening system of NSM CFRP rods was evaluated