Response of Reinforced Concrete Slab Elements to Torsion

Abstract

Methods of predicting the load‐deformation response of orthogonally reinforced concrete slab elements subjected to pure torsional moments in the reinforcement directions are presented. Uncracked, cracked, and ultimate behavior are discussed, treating the reinforcement as linearly elastic‐perfectly plastic and using linear, nonlinear (parabolic), and perfectly plastic stress‐strain relationships for the concrete. The softening effect of the transverse tensile strains on the response of concrete in compression is taken into account by adopting an empirical expression derived from tests on reinforced concrete panels subjected to membrane forces. It is shown that this softening effect has a significant influence on both stiffness and strength and that a yield‐line approach may considerably overestimate the ultimate torsional resistance.