1. Shanghai Research Institute of Building Sciences (Group), Co., Ltd., Shanghai 200032, China；
2. Shanghai Key Laboratory of Engineering Structure Safety, Shanghai 200032, China
Abstract：So far, there are a lot of existing multi-storey masonry residential buildings whose functions shall be upgraded by adding elevators, complete housing transformations and so on, while it shall be a beneficial exploration to improve the seismic behavior of masonry sturctures by the post-installed concrete walls. Three types of connections between post-installed concrete wall and masonry wall were proposed in this study, and cyclic loading tests were conducted on seven specimens including composite walls and reference walls. Their failure mode, hysteretic behavior, bearing capacity, deformation capacity, energy dissipation and ductility were investigated. Test results show that the proposed three types of connections are all capable of ensuring the cooperative work between the post-installed concrete wall and masonry wall, and the steel bar-embedding connection shall be the most convenient and practical. When the post-installed concrete wall is arranged asymmetrically, the stiffness degradations in the positive and negative directions are different, but the bearing capacity and deformation capacity in the two directions are similar. The bearing capacity, deformation capacity, energy dissipation and stiffness degradation of masonry wall can be greatly improved once concrete wall is added，and shear capacities of concrete and masonry walls can be fully used in the composite wall. In addition, 3D finite element methods based on cohesive interfacial model with contact property can be used very well to simulate the skeleton curve and failure mode of composite walls. A calculation formula for the shear capacity of composite wall was proposed, and its predictions agree well with the experimental results.
