Cracks in Concrete Subject to Shear

Shear tests on push-off specimens are carried out in order to study the strength and deformation behaviour of normal and lightweight concrete. Two types of specimen are used, one with embedded reinforcing bars and another with external restraint bars. In both series the experimental results show the dilatancy of cracked concrete under shear loading. The variables studied are the concrete quality, concrete composition, the reinforcement ratio, the bar diameter, the initial crack width and the influence of repeated loading. The concrete quality and the reinforcement ratio have the most pronounced influence on the behaviour. For the case of the external restraining force, diagrams are established to show the relation between shear stress, normal stress, crack width and shear displacement.