Seismic behavior of masonry walls strengthened by precast reinforced concrete panels with different connection details

Strengthening old masonry structures with precast reinforced concrete (RC) panels is a new strengthening method, which can save resources and construction time. Three connection methods, including RC dowelling keys, grouting agent and post-cast bands, were employed to ensure that the precast RC panels and the existing masonry wall work together. To investigate the seismic behavior of the strengthened structure, eight masonry walls were tested under quasi-static cyclic loading, including four reference walls and four strengthened walls. Experimental results show that the proposed strengthened method can effectively improve certain aspects of the seismic performance of existing masonry walls, such as shear strength, stiffness and energy dissipation capacity. The failure modes of all specimens were discussed. The shear capacity of original and strengthened masonry walls was evaluated using the existing design equations and proposed equations, respectively. The three proposed connection methods can ensure cooperation between the existing masonry wall and the precast RC panels. Among them, the post-cast band is the most effective measure, which is able to transfer 60%-80% load from the masonry wall to the precast RC panels.