Experimental Study on Seismic Performance of Precast Concrete Modular Superimposed Shear Walls with Innovative Intermodule Connections

Reinforced concrete (RC) modules with high lateral stiffness and load bearing capacity are preferred in high-rise modular buildings without additional lateral force resisting systems. In this study, a new self-supporting RC modular superimposed shear wall (RC-M-SSW) structural system with two innovative types of intermodule connectors is proposed for high-rise buildings. The precast module walls, cast-in-place concrete, and intermodule connections form the RC-M-SSWs to resist lateral forces. Two full scale RC-M-SSWs with different connection configurations and a reference cast-in-place shear wall were designed and tested given combined axial compression and lateral cycle loading to investigate the seismic performance of the modular superimposed shear walls. The results showed that the RC-M-SSW exhibited similar failure modes to the reference shear wall, and good integrity between the precast and cast-in-place concrete was observed. Moreover, the RC-M-SSW showed comparable load bearing capacity and energy dissipation capacity with the reference shear wall. The superior deformation capacity of the RC-M-SSWs meet the limit value requirements of the elastic-plastic drift ratio in Chinese code. The lateral load bearing capacity of the RC-M-SSWs can be accurately predicted using the calculation method in Chinese code with errors of no more than 3%. Finally, the effectiveness and reliability of those two types of intermodule connections was demonstrated through the strain analysis.