Strengthening strategies for unreinforced stone masonry walls using FRP and CFM composites

Recent earthquakes have highlighted the vulnerability of unreinforced masonry (URM) walls particularly those constructed with stone to lateral loads, underscoring the need for effective strengthening against shear failure. In this context, fiber-reinforced polymer (FRP) and carbon fiber mesh (CFM) have been explored as innovative alternatives to traditional reinforcement techniques. This study investigated unreinforced stone masonry walls, a common type of URM, strengthened using FRP and CFM materials in different configurations, focusing on the walls' in-plane shear behavior under diagonal compression testing. A reference specimen, labeled URM-1, was constructed without reinforcement. FRP materials were applied to two specimens either horizontally or diagonally on both wall surfaces. Similarly, two specimens were strengthened on both surfaces using CFM, applied with either epoxy or repair mortar. Based on experimental and analytical results, the URM-5 specimen (CFM with epoxy) was identified as the most effective strengthening method. It significantly increased maximum load capacity, shear stress, ductility, and elastic stiffness. Additionally, the URM-5 specimen reduced wall fragility and maintained structural integrity during fracture.