Experimental Study on Lateral Performance of Partially Encased Composite Shear Walls

With the application and promotion of prefabricated structures in China, the application value of PEC members in engineering has been greatly improved due to its characteristics of convenient mass production and rapid assembly. Some companies begin to try to apply PEC members in actual projects, and proposed a novel shear wall-PEC shear wall. Three full-scale PEC shear wall specimens were designed based on engineering application, and tested under low-cycle pseudo-static horizontal loading.The test phenomenon and failure process of PEC shear wall were observed, and the failure mode and deformation characteristics under the reciprocating load were studied by analyzing the stress and strain conditions of key parts. The hysteretic curve, skeleton curve, energy dissipation capacity, ductility, bearing capacity, stiffness and other mechanical properties of PEC shear wall under the low cyclic loading were analyzed to evaluate its lateral resistance properties. The influence of the flange crimping construction on the failure characteristics, deformation and lateral resistance were compared to verify its validity. And the influence of the axial compression ratio on the lateral performance of PEC walls with crimping construction was analyzed. The test results show that: 1)all PEC shear wall specimens failed after yielding due to bending, and the steel flange yielded before reaching the maximum bearing capacity. The concrete collapse at the bottom of specimen SW1 caused local buckling of the steel flange, while the bottom steel flange of specimen SW2 and SW3 did not buckled, and finally the base anchoring failure occurred. 2)Specimen SW1 hysteresis curve of SW1 is full, which has strong ability of plastic energy dissipation; hysteresis curves of specimen SW2 and specimen SW3 have a certain degree of pinch phenomenon. The ductility indexes are greater than 3.4, which has good deformation ability. The deterioration of wall resistance is much limited, and stiffness degrades is at a slower rate during later loading stages. All of the specimens keep stable bearing capacity within 1/30 inter-story drift.3) The crimping construction efficiently confines the concrete at the bottom corner of the PEC shear wall, postpones the collapse of the concrete, and makes the PEC shear walls have better bearing capacity. 4)Under high axial compression ratio, the specimen will compressively yield earlier, while the initial stiffness of the PEC shear wall will increase somewhat, meanwhile, its ductility and energy dissipation capacity will be reduced. 5) The deformation capacity of PEC shear wall is closer to that of steel plate shear wall than that of concrete shear wall. The deformation limit for seismic design of PEC shear wall can be appropriately enlarged.