Title: Shear-Strength Model for Slab-Column Connections Subjected to Unbalanced Moment (with Appendix)

Author(s): Kyoung-Kyu Choi, Dong-Woo Shin, and Hong-Gun Park

Publication: Structural Journal

Volume: 111

Issue: 3

Appears on pages(s): 491-502

Keywords: eccentric shear; footings; punching shear strength; slab-column connections; unbalanced moment

DOI: 10.14359/51686533

Date: 5/1/2014

Abstract:
A shear-strength model for slab-column connections without shear reinforcement was studied to predict the direct punching shear strength and the unbalanced moment-carrying capacity. Neglecting the shear contribution of a tension zone severely damaged by flexure-shear cracks, the punching shear at a critical section was assumed to be resisted mainly by the compression zone of the slab cross section. The shear strength of the compression zone was defined as a function of the compressive normal stress developed by the slab flexural action, using the material failure criteria of concrete. For the evaluation of the unbalanced moment carrying capacity of the slab-column connections, eccentric shear strength was defined differently at each face of the critical section around the slab-column joint, considering the degree of flexural damage of the slab. For exterior slab-column connections, the proposed model was defined in the unsymmetrical critical section. The proposed model was applied to existing test specimens of interior and exterior slab-column connections, and column footings. The results showed that the proposed strength model predicted the test results with reasonable precision.