Seismic performance of innovative precast concrete composite walls with embedded XPS insulation layer

Four precast concrete composite walls with embedded extruded polystyrene insulation layer were designed, and the seismic performance was systematically investigated. The failure mode, hysteretic curve, skeleton curve, stiffness degradation, displacement ductility and energy dissipation capacity were explored by quasi-static tests. Moreover, the strain variation of reinforcements at the key positions of the specimens was analyzed and discussed. The test results indicated that the failure mode of the specimen with extruded polystyrene insulation layer thickness of 200 mm was flexural failure, accompanied by the concrete crushing and spalling at the wall toes; while the specimen with extruded polystyrene insulation layer thickness of 100 and 120 mm showed better cooperative working performance. The precast composite concrete wall adding diagonal braces possessed better bearing capacity, deformation capacity and cumulative energy dissipation capacity. Furthermore, the connecting reinforcements at the horizontal joint can effectively transfer stress. Finally, a simplified calculation model of bearing capacity of the precast concrete composite walls with embedded extruded polystyrene insulation layer connected by tooth groove and grouted sleeve was proposed.