MECHANICAL BEHAVIOR OF MASONRY WALLS RETROFITTED WITH PREFABRICATED REINFORCED CONCRETE PANELS

Assembly technology using prefabricated reinforced concrete (RC) members can effectively improve the seismic performance of existing masonry buildings. In this study, an existing masonry wall is enhanced using two pieces of prefabricated RC panels, which are bonded on the two faces of the wall. To enable full interaction between the prefabricated RC panels and the masonry wall, three techniques are employed and studied, specifically connections provided by RC dowels, connection via grouting agent, and connection using post-casting concrete bands. To investigate the interaction and the force transfer mechanism between the RC panels and the masonry wall, a finite element analytic model was developed to simulate the quasi-static cyclic tests and nonlinear analyses were conducted. Results demonstrate that the addition of prefabricated RC panels using the proposed retrofitting techniques can effectively improve the seismic performance of the existing masonry walls. The strength of an existing wall can be increased by three to four times and the stiffness by two to three times when it is retrofitted using the prefabricated RC panels, satisfying the requirements of the current seismic design code. Among the three connection methods, post-casting concrete bands are most effective, as they are able to transfer 70% of the load from the masonry wall to the RC panels in the elastic phase, and up to 80% of the load in the nonlinear ultimate phase.