Numerical Investigation of punching shear behavior of reinforced concrete flat slab with openings

Abstract

Reinforced concrete (RC) flat slabs are widely used in modern civi buildings due to their flexibility in architectural layout, rapid construction, and cost efficiency. However, these slabs are susceptible to sudden brittle failure, particularly when openings are located near columns or walls. This study evaluates the punching shear capacity of RC flat slabs with openings in accordance with ACI 318 – 19, Eurocode 2, and BS 8110 – 1997, and compares the calculated results with previously published experimental data. Subsequently, a finite element (FE) model was developed in Cast3M to simulate the punching shear behavior of the slabs. The model exhibited good agreement with experimental observations in terms of load–deflection curves, load–strain relationships, and failure patterns. The results indicate that openings adjacent to the column significantly reduce the slab’s punching shear strength, while moving the openings farther away can increase the capacity by up to 15%. Moreover, slabs with circular openings demonstrated approximately 10% higher punching capacity compared to those with square or rectangular openings of equivalent area.