Influence of aggregate geometry and material fabric on tensile cracking in concrete

Abstract A recently developed discrete element capability is used to understand the effect of random variations in aggregate shape and size on tensile cracking in concrete. A procedure to reconstruct the three-dimensional crack surface, and characterize its tortuosity, is proposed. The role of anisotropy in the material fabric, induced by variations in aggregate shape, is studied. Both tensile and compressive strength are seen to be affected by fabric anisotropy, but to different extents and in different ways. Post-peak behaviour in tension is linked to dispersion in the local fabric, characterized by a proposed local fabric tensor. The influence of aggregate shape on fracture process zone geometry is investigated. Overall, aggregate shape appears to be the dominant factor in determining the post-peak response. However aggregate size appears to affect the tensile strength more strongly while its influence on the fracture energy is complicated and subject to two opposing trends.