Experimental study on the seismic performance of fully prefabricated L-shaped double-skin composite shear wall with corrugated duct-reinforced boundary elements

In this study, a novel fully prefabricated L-shaped double-skin composite shear wall with corrugated duct-reinforced boundary elements (PCSW) is proposed. By prefabricating strengthened boundary elements with built-in corrugated duct in the factory, the PCSW significantly improves both seismic performance and construction efficiency of composite shear walls. To investigate the effects of axial compression ratio, corrugated duct configuration, vertical joint detailing, and strength of double-skin composite wall panels on the seismic performance of PCSW, quasi-static tests were conducted on six full-scale L-shaped specimens, including four PCSW specimens and two cast-in-situ shear walls (CSW) control specimens. The results indicated that the failure patterns of PCSW and CSW differ significantly. PCSW failures are predominantly characterized by joint and composite wall panels damage, whereas CSW failures manifest as severe damage to boundary elements. Under high axial compression ratios, PCSW exhibited significantly reduced damage in boundary elements compared to CSW, along with plump hysteresis curves without pinching effects, attributed to the effective confinement of concrete deformation in boundary elements by corrugated ducts, which enhanced their load-bearing capacity and deformability. Under varying axial compression ratios, the PCSW consistently demonstrated superior seismic performance compared to CSW, with maximum improvements of 11.2 % in load-bearing capacity, 61 % in ultimate displacement, and 49.6 % in energy dissipation capacity. Strengthening vertical joints and double-skin composite wall panels significantly enhances the overall performance of PCSW, with load-bearing capacity and ductility coefficient improvements of 24.4 % and 28.8 %, respectively. A theoretical formula for predicting the load-bearing capacity of PCSW was developed based on failure characteristics and validated against experimental data. The excellent test performance of the PCSW demonstrates its feasibility for application in prefabricated concrete structures.