Analysis of punching shear failure in connections between reinforced concrete slab and T-shaped steel reinforced concrete column

Abstract

To enhance the punching capacity and ductility of slab–column connections, a new type of reinforced concrete (RC) slab–T-shaped steel reinforced concrete (SRC) column connection was proposed and studied. The punching performance of this new connection type was investigated through five quasi-static tests under concentrated loading, focusing on the influence of slab thickness and column cross-sectional geometry. The test results indicate that increasing the thickness of the slab can significantly improve both the stiffness and punching shear capacity of the connections. While the T-shaped column section induces a more complex shear stress distribution around the slab–column interface, but does not change the failure mode. To further explore the structural behavior, parametric analyses were conducted using ABAQUS finite element software. Results suggest that the presence of steel in the column has limited influence on the initial stiffness and punching shear capacity of the slab–column connections, but contributes to improved residual strength and ductility due to the suspension effect of the reinforcement in the slab. Additionally, The change of the limb height-to-thickness ratio were found to slightly affect the unit shear stress along the critical perimeter, though the overall impact was minor. Based on the combined test and numerical studies, design recommendations for column cap dimensions in slab–T-shaped column connections were proposed to guide practical applications.