A meso-level approach to the 3D numerical analysis of cracking and fracture of concrete materials

A meso-mechanical model for the numerical analysis of concrete specimens in 3D has been recently proposed. In this approach, concrete is represented as a composite material with the larger aggregates embedded in a mortar-plus-aggregates matrix. Both continuum-type components are considered linear elastic, while the possibilities of failure are provided with the systematic use of zero-thickness interface elements equipped with a cohesive fracture constitutive law. These elements are inserted along all potential crack planes in the mesh a priori of the analysis. In this paper, the basic features of the model are summarized, and then results of calculations are presented, which include uniaxial tension and compression loading of 14-aggregate cubical specimen along X, Y and Z axes. The results confirm the consistency of the approach with physical phenomena and well-known features of concrete behaviour, and show low scatter when different loading directions are considered. Those cases can also be considered as different specimens subjected to the same type of loading.