Shear strength components of concrete under direct shearing

Direct shear tests on concrete specimens were conducted to investigate the shearing behaviour of the material under varying normal confining stresses. Test results were analyzed to quantify the mobilization of shear strength components derived from hydrated cement paste–aggregate adhesion, contact friction, shear dilation, and cement–aggregate interlock along the sheared surface under direct shearing. It was found that each component has its unique response in terms of mobilized shear stress and shear displacement. In addition, different modes of failure observed in uniaxial compression, splitting tension, and direct shear tests were identified to delineate the Mohr–Coulomb failure envelope for shear strength of concrete material.