Experimental and Analytical Evaluation of Confined Masonry Walls Retrofitted with CFRP Strips and Mesh-Reinforced PF Shotcrete

Abstract

This study evaluates the performance of retrofitted confined unreinforced masonry walls using carbon fiber–reinforced polymer (CFRP) strips and mesh-reinforced shotcrete. Polypropylene-fiber (PF) concrete was applied in the shotcrete retrofitting. Four full-scale confined unreinforced masonry walls were experimentally tested under in-plane lateral cyclic loading. The first nonretrofitted wall was built as a reference model. The second and third walls were retrofitted with carbon fiber–reinforced polymer strips in grid and diagonal layout, respectively. The fourth wall was retrofitted with mesh-reinforced PF shotcrete. The stiffness, strength, ductility, and modes of failure of the nonretrofitted confined masonry wall and the retrofitted confined masonry walls were determined and compared. The strength of the retrofitted walls with the grid and diagonal layout of carbon fiber–reinforced polymer increased up to 35 and 15%, respectively. However, the strength of the mesh-reinforced shotcrete retrofitted wall increased up to 55%. The ultimate mode of failure of the retrofitted experimental models changed compared to the reference model. A micromodel was used for the walls and micromechanical model for the carbon fiber–reinforced polymer strips to calibrate the numerical analysis with the experimental models. The numerical finite-element analysis of the models was carried out under monotonic loading. The numerical analysis reproduced the key behavior of the experimental models, including the load-displacement response and crack development.