Shake table test on a five-story residential masonry building strengthened by engineered cementitious composites based on minimum disturbance

Multi-storey masonry structures are popular structural systems for residential buildings in China in the 1970 s, which need strengthening urgently due to poor seismic performance. To save construction time and achieve minimum disturbance, a single-sided engineered cementitious composites (ECC) strengthened method for masonry structures was proposed. To investigate the effectiveness of the strengthening method, two 1/4-scaled 5-storey masonry structures, including a reference unreinforced structure (US) model and a corresponding retrofitted structure (RS) model, were designed and tested by shake table tests. The comparisons between the US model and the RS model were analyzed in terms of the natural frequency, acceleration amplification factor, acceleration response, and storey drift response. The results show that the strengthening method can improve the seismic performance of the masonry structure. The connection method can ensure that the existing masonry walls and ECC layers work together. The initial natural frequency of the RS model is 1.3 times that of the US model. The maximum storey drift of the US model is 3.0 times that of the RS model at PGA = 0.550 g. To ensure the strengthening efficiency, the acceptable structural aspect ratio range for the strengthening method was suggested, and an improved strengthening method was proposed.