Numerical simulation of punching shear in flat slabs with spherical voids subjected to symmetric and asymmetric loadings

Abstract

Using hollow spherical voids within slabs brings the already-known advantages of conventional flat slab systems with the weight reduction caused by removing concrete from less stressed structure regions. However, it is necessary to carefully assess the punching shear phenomenon, mainly when unbalanced loads are applied. Thus, a numerical simulation using the Finite Element Method was developed, and validated with experimental data from four slabs, one solid, and three slabs with spherical voids. The results demonstrated good approximations when unbalanced loads were considered for load-displacement behavior, load-strain in concrete and reinforcements, and failure surface. Overall, a decrease in ultimate load, stiffness, and load at the first crack was identified when spherical voids were used.