Investigation of Shear Strengthening Methods for Reinforced Concrete Beams Using FRP

Shear strengthening of reinforced concrete (RC) beams using fiber-reinforced polymer (FRP) composites has been recognized as an effective technique to enhance shear capacity and mitigate brittle failure modes. Owing to their low weight, corrosion resistance, and ease of installation, FRP materials have become a widely adopted solution for the shear upgrading of RC members. This study reviews two major strengthening approaches—externally bonded (EB) systems and near-surface mounted (NSM) reinforcement. In the EB technique, FRP sheets or strips are bonded directly to the concrete surface; however, premature debonding often limits their effectiveness. The NSM method, in which FRP strips or bars are embedded into pre-cut grooves on the concrete surface, provides superior bond performance and improved force transfer, although its installation is more demanding. Furthermore, various anchorage systems, including metallic anchors, horizontal FRP strips, and FRP-based anchors, have been developed to delay or prevent debonding and to enhance the efficiency of FRP shear reinforcement. The reviewed literature indicates that full wrapping and U-jacket configurations offer the highest shear-strengthening effectiveness. NSM strengthening combined with FRP anchors particularly those applied at ۴۵° has shown the most favorable performance. By synthesizing recent research findings, this study provides a comprehensive insight into effective FRP shear strengthening approaches for engineers and researchers.

کلیدواژه ها:

Reinforced concrete beam ، FRP ، EB ، NSM ، Shear strengthening