Abstract
The paper presents a rational procedure for evaluating the concrete shear strength in reinforced concrete beams. Previous research has shown that the shear in concrete is resisted by various mechanisms and the resistance degrades with the increase of flexural deformation. The paper introduces a novel approach in utilizing the knowledge about shear resistance degradation by coupling the shear resistance with the shear demand. Both the shear resistance and shear demand are correlated with flexural tensile strain from compatibility and equilibrium requirements. The basic shear strength, under a given loading is determined from the intersection of the demand and resistance curves. The procedure was verified against a database of 232 beams collected from 10 sources with a broad range of parameters. It showed good prediction capability and can be useful to design practice.