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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.

Due to the low lateral stiffness of slabs supported on columns alone, reinforced concrete flat plates are typically combined with other structural elements, such as shear walls. In these structures, the slab–column connections are designed to carry gravity loads only, and the shear walls are required to resist both gravity and lateral forces. Therefore, the slab–wall connections are essential for the performance of both the gravity and lateral force resisting systems. However, most punching shear research and design provisions are focused on slab–column connections, even though punching failures around slab–wall connections have occurred experimentally. Empirical testing of slab–wall connections is difficult due to the specimen size. This paper investigates the punching shear behavior of interior slab–wall connections subjected to concentric vertical loading, and combined concentric vertical loading and uniaxial unbalanced moment using a plasticity‐based nonlinear finite element model (FEM) in ABAQUS. The analysis of isolated slab–wall connections demonstrates that punching failures can occur before one‐way shear failures. Since the overall connection capacity is much higher than the expected loads in most structures, if these punching failures happen they would be localized to the region around the wall end and are not expected to lead to structural collapse.

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