Effectiveness of arch behaviour in reinforced concrete beams subjected to shear

Abstract

The shear resistance of reinforced concrete elements without transverse reinforcement relies on the interaction of several resisting mechanisms. In the region close to the supports of a suspended element, the greatest contribution is often provided by the so-called arch behaviour. This load-carrying mechanism fundamentally consists of a flow of inclined compressive stresses within the depth of a flexural element, which transfers the force from the support reaction to the top com-pression chord of the beam. Several theories have been developed in the past to describe this behaviour. There are analogies among different theories, in that the effectiveness of this resisting mechanism depends on the disturbance to the compressive stresses within this arch. Such disturbance can depend upon several factors, including reinforcement ratio and the characteristics and evolution of the cracking pattern. Despite the commonalities between theories, certain aspects are still subject to scientific debate. One of them is the interaction between the arch behaviour and other resisting mechanisms. In this study, an analysis of the shear behaviour and cracking pattern of reinforced concrete beams without transverse reinforcement was carried out. Analytical predic-tions and experimental results were also compared. The results given an insight into the interaction between internal resisting mechanisms in shear and their mutual interference. The findings of this study can lead to the development of more efficient reinforced concrete structures.