Cyclic In-Plane Shear Behavior of Composite Plate Shear Walls-Concrete Encased

Abstract

Steel-plate composite walls comprise a steel plate encased in the middle of a reinforced concrete shear wall [referred to as “composite plate shear walls-concrete encased (C-PSW/CE)”], or a concrete infill sandwiched between two steel faceplates [referred to as “double-skin composite (DSC) walls”]. In this study, two I-shaped C-PSW/CE specimens with a shear-to-span-ratio of 1.2 were experimentally tested to investigate the cyclic in-plane shear behavior of C-PSW/CE used for high-rise buildings. Both wall specimens were identical in geometric dimensions and reinforcement details, with the exception of axial force ratio. The results indicated that shear failure occurred in the two wall specimens due to serious spalling of web concrete, followed by buckling of the embedded steel plate and vertically distributed reinforcements. The increase in axial force ratio from 0.16 to 0.29 resulted in an 11.8% rise in peak strength and a decrease in ultimate shear strain of 27% for C-PSW/CE. A comparison between C-PSW/CE and DSC walls indicated that the latter had a similar peak strength to the former, but clearly improved the ultimate drift. This is because the double faceplates of DSC walls provided a more effective restraint to the infilled concrete and prevented spalling of concrete. Then, this paper developed a refined numerical model to simulate C-PSW/CE and compared the analytical results with the experimental data. Finally, shear strength design formulas specified in Chinese and US codes were verified against a large volume of test data and numerical simulation results. The shear strength of C-PSW/CE was reasonably estimated by the JGJ 3-2010 design formulas (Chinese code), while significantly underestimated by the AISC 341-16 formula (US code) which neglects the shear contribution of reinforced concrete encasement.