Parametric investigation of the effect of moment transfer on the punching shear strength of slab-column connections

Abstract

High shear stresses are concentrated in slab-column connections, favoring the occurrence of punching shear failure. In building projects, the transfer of unbalanced moments in the slab-column connection is common, significantly reducing the punching resistance. However, standards such as ACI 318 (2019) and NBR 6118 (ABNT, 2023) are based on empirical formulations obtained from experimental tests, presenting greater inaccuracy for cases with unbalanced moments. In this sense, computational modeling can contribute to the development of this subject. Therefore, this work initially sought to present nonlinear numerical modeling, using the finite element software ATENA, of specimens of reinforced concrete slab-column connection without shear reinforcement subjected to unbalanced moments experimentally tested by Kruger (1999). Validating the computational models, by comparing the results of load versus displacement, vertical displacement profile, damage evolution and rupture surface. From this validation, a parametric study was carried out based on these computational models, varying the loading eccentricity (e). Comparing the results obtained from the parametric analysis with the normative predictions of ACI 318 (2019) and NBR 6118 (ABNT, 2023). Obtaining results that indicate the effects caused by eccentricity on the punching resistance.