Airbag loading test and numerical simulation on out-of-plane mechanical behavior of a cast-in-situ composite wall with MTPC

Although infilled walls are designed to serve as nonstructural components in frame buildings, their out-of-plane (OP) collapse during earthquake events may trigger additional damage to other structural components and inflict heavy casualties. Taking advantages of the metal tailing porous concrete (MTPC) and light-gauge steel studs, a new cast-in-situ composite wall with MTPC (CCWM) can be developed and regarded as a potential substitute for traditional masonry infilled walls. This paper experimentally investigates the OP mechanical behavior of a full-scaled CCWM via airbag loading test. A CCWM specimen with dimension of 2.4 m × 1.2 m × 0.2 m is fabricated by pouring MTPC into the cavity formed by panels and light-gauge steel stud system. The specimen is placed vertically in an elaborate loading system composed of steel frame, reaction brace, horizontal beams and a polyethylene airbag. Under the uniform OP force provided by the slowly inflated airbag, the failure pattern, load-displacement curves and strains of light gauge steel studs of the CCWM are observed and recorded during the test. Moreover, the finite element model of the specimen is developed in ABAQUS platform and the effects of slenderness ratio and aspect ratio on the OP mechanical behavior of the CCWM are numerically investigated. The results indicate that the specimen cracked vertically along the central line of the upper half part of the wall, and the connections between the support plates and vertical lattice studs are vulnerable locations for the CCWM. Owing to the special constitution of the CCWM, the arching action is short-term, and the crack strength can be adopted as the OP bearing capacity of the CCWM since it is quite close to the ultimate strength. Moreover, numerical results reveal that the OP strength and stiffness of the CCWM decrease when the slenderness ratio increases, but enhance with increasing aspect ratio.