Seismic Performance of Unreinforced Masonry Walls with Various Retrofitting Methods

Abstract

ABSTRACT This study proposed practical retrofitting methods to enhance the seismic performance of unreinforced masonry walls, utilizing textile-reinforced mortar (TRM) composites, glass fiber-reinforced polymer (GFRP) strips, and fiber-reinforced cementitious composites (FRCC). Retrofitting materials were applied at wall boundaries using the cast-in-place method with and without anchorage. Four masonry wall specimens, one control and three retrofitted, were fabricated and tested under lateral cyclic loading conditions to assess retrofitting efficiency. Various parameters were assessed, including hysteresis response, ductility, stiffness degradation, and energy dissipation capacity. The results indicated that TRM and FRCC retrofitting techniques exhibited an improvement in both the strength and deformation capacity. Among the retrofitting approaches, FRCC combined with steel reinforcement anchored to bottom beams showed superior performance Meanwhile, although exhibiting strength improvement, the ductility of the specimen retrofitted with FRP strips decreased post-peak due to severe splitting cracks. Lastly, an analytical strength model was proposed to predict lateral load-carrying capacity, demonstrating a reasonable correlation with test results. For the future application of the proposed retrofit methods, appropriate anchorage details for TRM and GFRP techniques are needed to be developed which could enhance deformation capacity in the post-peak stage of the retrofitted walls.