Out-of-plane strengthening of URM walls using different fiber-reinforced materials

Abstract

Fiber-reinforced polymers (FRPs), textile-reinforced mortars (TRMs), and engineered cementitious composites (ECCs) have been extensively employed to address the insufficient load-carrying capacity and low deformation capability of unreinforced masonry buildings. In this study, eight groups of unreinforced masonry walls were built to test the efficiencies of various reinforcing methods under out-of-plane four-point loading. A high-strength mortar reinforcement were employed as benchmarks. Four types of ECCs—low-cost, high-strength, lightweight insulation, and high-toughness ECCs—were compared with carbon FRP (CFRP) sheet and TRM systems. The failure modes, midspan load–displacement actions, energy absorption capabilities, initial bending stiffness values, and ductility of the different reinforcement systems were obtained and analyzed. The results revealed that the TRM-reinforced specimens experienced the maximum midspan deformation. The best ductility and maximum bearing capacity were obtained respectively after reinforcements with high-strength and high-toughness ECCs. However, the exploitation of the CFRP sheet was limited owing to excessive reinforcement. Finally, the moment capacity was evaluated using a flexural model. For the specimens that failed in the shear mode, a shear model based on the equilibrium condition was established to predict their load-carrying capacities.