Behaviour of concrete under shear and normal stresses

Abstract

Thirty-eight concrete specimens were tested in a servo-controlled shear box test machine. The aim of the tests was to determine the combination of stresses that would cause failure in the concrete and to compare the failure stresses with Mohr–Coulomb theory. It was found that the failure load of specimens tested under a constant normal force could be predicted using Mohr–Coulomb theory with an assumed friction angle of 35°, provided that the normal stress was greater than 0·15fc. For normal stresses less than 0·15fc Mohr–Coulomb theory overestimated the shear capacity of the concrete unless a modified cohesion value and friction angle were used.