ABSTRACT
The transverse loads on a beam segment cause a bending moment and a shear force that vary across the beam cross section. Concrete has a tendency to crack along the plane subjected to tension when the level of stress exceeds a certain value. The cracks form near the mid-depth where the shear stress is maximum and move in a path diagonal to the tensile surface. The web reinforcement represents the vertical tensile member. According to the truss analogy theory, the entire applied shear force that induces the diagonal tension is resisted only by the web reinforcement. But observations have shown that the tensile stress in the web reinforcement is much smaller than the tension produced by the entire shear force. With flexure reinforcement but without web reinforcement, concrete does not contribute in resisting the diagonal tension once the diagonal crack is formed.
