Transition between Shear and Punching in Reinforced Concrete Slabs: Review and Predictions with ACI Code Expressions

One-way slabs under concentrated loads may fail by one-way shear, two-way shear, flexure, or a combination of these modes. This paper reviews shear and punching shear-failure mechanisms of one-way slabs under concentrated loads tested from the literature and investigates the accuracy of different approaches to predict the ultimate capacity for such slabs using the ACI code expressions. A database with 160 test results was evaluated. Shear and concentrated loads measured at failure were reviewed according to parameters such as the load position, slab width, and reinforcement ratios. The load position and slab width play a marked influence on the failure mechanism and tested loads. The analyses improved the understanding of the main parameters influencing the behavior of one-way slabs under concentrated loads. Finally, the proposed effective shear width expression enables accurate shear capacity predictions using the ACI code expressions.