Punching Shear Capacity Model in Reinforced Concrete Flat Slab Without Shear Reinforcement, Based on Fracture Mechanics and Statistical Approach

ABSTRACT Reinforced concrete (RC) flat slabs are cost‐effective and structurally efficient, but they are vulnerable to brittle punching shear failure at the connections between slabs and columns. However, existing design formulations lack the simplicity and accuracy needed to capture this behavior under concentrated loads. Therefore, improved and accurate models predicting punching shear capacity are needed. This study presents a fracture mechanics‐based model for evaluating the punching shear capacity of concrete flat slabs without shear reinforcements. The model's prediction is evaluated against 141 experimental test results reported in the literature to verify its accuracy, reliability, and consistency. The model achieves mean, coefficient of variation (COV), mean absolute error (MAE), and R 2 values of 1.01%, 13.21%, 11.55%, and 0.93, respectively. Comparison with existing models from different researchers and design codes demonstrated that the proposed model offers superior reliability and accuracy. Its enhanced performance is attributed to the incorporation of critical parameters such as reinforcement ratio, crack‐opening behavior, and aggregate interlock, which are often neglected in some conventional formulations. Sensitivity analysis confirmed the model's robustness across various parameters, including slab dimensions, reinforcement ratio, and concrete strength.