New results in 3D meso-mechanical analysis of concrete specimens using interface elements

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 64 and 137-aggregate cubical specimens. The results confirm the consistency of the approach with physical phenomena and well-known features of concrete behavior, and show low scatter between specimens of different size and number of aggregates but similar volume ratio.