Nonlinear finite element analysis of punching shear strength of reinforced concrete slabs supported on L-shaped columns

Abstract

Most current concrete design codes include provisions for punching shear of reinforced concrete slabs supported on columns with L, T, and cruciform shapes. Reference studies verifying the accuracy of these code provisions are typically not provided. Empirical data of punching failures of slabs supported on columns with L, T, and cruciform shapes are limited due to the cost and time required to test specimens with slab thicknesses and column sizes commonly used in practice. In this paper, the punching shear behaviour of five interior L-shaped slab-column connections, one without a slab opening and four with slab openings, subjected to static concentric loading are analyzed using a plasticity-based nonlinear finite element model (FEM) in ABAQUS. The FEM is similar to models previously calibrated at the University of Waterloo and are calibrated considering nine slabs that are tested to study the impact of column rectangularity on the punching shear behaviour of reinforced concrete slabs. The finite element analysis results indicate that shear stresses primarily concentrate around the ends of the L, and that current code predictions from ACI 318-19 and Eurocode 2 may be unconservative due to the assumed critical perimeters around L-shaped columns.

Finite element analysis of punching shear behavior of reinforced concrete slabs supported on walls

“…The presented work is part of an ongoing study at the University of Waterloo focused on analyzing the effect of support geometry on the punching behavior of reinforced concrete slabs. 10,11,18,[23][24][25] Building frames comprised of column-supported slabs are generally too flexible to adequately withstand lateral loads, therefore such structures commonly include shear walls as the principal lateral load-resisting elements. In such structural systems, the slab-column connections are typically designed to carry gravity loads only, whereas the shear walls are required to support both gravity and lateral loads.…”

“…In this paper, the punching shear behavior of interior slab–wall connections subjected to concentric vertical loading only and combined concentric vertical loading and uniaxial unbalanced moment is studied using nonlinear FEA. The presented work is part of an ongoing study at the University of Waterloo focused on analyzing the effect of support geometry on the punching behavior of reinforced concrete slabs 10,11,18,23–25 …”