Seismic performance and deformation mechanism of precast single-face superposed shear wall

The application of single-face superposed (SFS) shear walls in high-rise residential buildings within seismic zones has attracted extensive attention in past years, but the seismic performance of SFS shear walls hasn't been well understood yet. This study presents the results of quasi-static cyclic tests on four precast SFS shear walls using different horizontal joints and one cast-in-place (CIP) shear wall. The main objective is to achieve a thorough knowledge of the deformation behavior and deformation mechanism of SFS shear walls by analyzing the experimental results describing the global and local deformation behaviors. In general, SFS shear walls behaved equivalently to or even slightly better than the CIP shear wall in terms of bearing capacities, ductility properties, stiffness degradations, and energy dissipation properties. However, unlike the flexure-shear-dominated deformation mode of the CIP shear wall, SFS shear walls were primarily dominated by rigid body rotation behavior and secondarily by flexural-shear deformation. Based on the experimental results, the significant influence of the strain development of vertical rebars, opening, and slip at the horizontal joint on the deformation behavior of SFS shear walls was discussed. It was found that the continuously increasing opening, the sequential yielding of vertical rebars, and the slip at the horizontal joint together led to the difference in deformation behavior between SFS shear walls and the CIP shear wall. Therefore, future work will investigate whether SFS shear walls could emulate well CIP shear walls if the severe deformation at the horizontal joint is greatly reduced.