Shear Strength of Concrete Members: Challenges, Recent Developments and Possibilities

Abstract

Shear strength of concrete members has always been a complex topic, and even today, there is no widespread agreement regarding a shear resistance model. Nevertheless, the primary resistance mechanisms have been identified [1] shear transfer through uncracked concrete, aggregate interlock along cracks, dowel action of longitudinal reinforcement, arch action for short and deep members, and amount of shear reinforcement. It is assumed that the shear strength is the sum of the concrete contribution and the shear reinforcement contribution. However, the quantification of these mechanisms is not straightforward. The shear strength of concrete members is influenced by tensile concrete strength, coarse aggregate size, presence of axial force, slenderness ratio (M/Vd or a/d, where M is the bending moment, V is the shear force, d is the effective depth of the longitudinal reinforcement, and a is the shear span, i.e., distance between the applied load and the support), amount of longitudinal reinforcement, and overall size of the member. Yet, the relative influence of these variables is still debated.