New modular precast composite shear wall structural system and experimental study on its seismic performance

Abstract

Modular buildings are becoming increasingly popular due to their higher construction efficiency, better quality control and less resource consumption. In this study, a new modular precast composite shear wall structural system was proposed and the joint design principle was given. The new modular precast structural system adopted volumetric concrete modules and dry bolted connections for fully precast construction and demountable ability. This paper presented comparative shaking table tests and comprehensive test result analyses on a modular precast composite shear wall model and a cast-in-place shear wall model. The fundamental frequency of the modular precast model was 10.2% lower than that of the cast-in-place model because of the semi-rigid joints. The modular precast model exhibited comparable dynamic responses with the cast-in-place model, but showed less severe shear wall damage under the same intensity level test due to the small gap opening of vertical joints. The screw fracture and nut slip in vertical joints induced the failure of the modular precast model. The modular precast model exhibited better energy dissipation performance than the cast-in-place model. The adjoining concrete modules could achieve satisfactory synergistic working performance, and the horizontal joints remained elastic throughout the tests. The excellent test performance of modular precast composite shear wall model confirmed the feasibility of the proposed structural system in concrete modular buildings.