Recycled concrete brick (RCB) is manufactured by recycled aggregate processed from discarded concrete blocks arising from the demolishing of existing buildings. This paper presents research on the seismic performance of RCB masonry walls to assess the applicability of RCB for use in rural low-rise constructions. The seismic performance of a masonry wall is closely related to the vertical load applied to the wall. Thus, the compressive performance of RCB masonry was investigated firstly by constructing and testing eighteen RCB masonry compressive specimens with different mortar strengths. The load-bearing capacity, deformation and failure characteristic were analyzed, as well. Then, a quasi-static test was carried out to study the seismic behavior of RCB walls by eight RCB masonry walls subjected to an axial compressive load and a reversed cyclic lateral load. Based on the test results, equations for predicting the compressive strength of RCB masonry and the lateral ultimate strength of an RCB masonry wall were proposed. Experimental values were found to be in good agreement with the predicted values. Meanwhile, finite element analysis (FEA) and parametric analysis of the RCB walls were carried out using ABAQUS software. The elastic-plastic deformation characteristics and the lateral load-displacement relations were studied.

Based on the excellent performance of shear metal dampers in building seismic capacity, the traditional shear metal damper was optimized. A double-sided shear steel tube damper with simple structure, easy replacement, and wide application is proposed. In order to study the influence of different design parameters on its seismic performance, taking the steel tube length, height, width, thickness, and connection mode as variables, five groups of 15 specimens were designed for experimental research, and the failure modes, characteristic loads and displacements, hysteretic curves, skeleton curves, stiffness degradation curves, and energy dissipation capacity of each specimen were analyzed in detail. The test results showed that the hysteretic curves of each specimen were full and that the energy dissipation capacity was good. The greater the thickness of the steel tube was, the greater the load-bearing capacity of the damper and the larger the hysteresis loop area were. The greater the width of the steel tube was, the greater the equivalent stiffness was. As displacement amplitude increased, the equivalent stiffness of the specimen showed a downward trend. The two connection modes had their own advantages and disadvantages, and a damper with reasonable connection form would need to be selected according to actual engineering needs.

A total of four full-scale low-rise recycled aggregate concrete shear wall specimens were tested adopting a quasi-static loading method to analyze the seismic performance. The low-rise shear walls consisted of recycled aggregate concrete, single-layer reinforcements, concealed special-shaped columns, and expanded polystyrene thermal insulation modules. Based on the experimental results, the seismic performance and failure characteristic of the specimens were comparatively analyzed. The factors affecting the seismic performance of the low-rise shear wall were also analyzed. The shear bearing capacity calculation model and formula of the walls were proposed based on the softened strut-and-tie model. A comparison of the calculated results and the experimental results shows that they are in good agreement. The results show that the load bearing capacity and deformation capacity can be significantly improved by expanded polystyrene thermal insulation modules, and that the shear wall specimens with higher recycled aggregate concrete strength and larger reinforcement ratio of the shear wall exhibit better seismic performance.

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