Abstract:Concrete is a three-phase composite material composed of coarse aggregate, mortar matrix and interface transition zone (ITZ) at mesoscale. At present, a large number of mesoscopic numerical experiments have been carried out in consideration of different mechanical properties among these three phases. However, concrete is a typical multi-scale material, and each phase is heterogeneous at mesoscale. In view of this, this paper proposed a stochastic damage model of the representative volume element (RVE) at mesoscale, and the corresponding finite element program is developed. Then the uniaxial tensile and compressive numerical test of the random aggregate model, and the uniaxial tensile test of the double-aggregate model are conducted to validated the model. The results show that despite the simplicity of the model, it can reflect the main macro-mechanical behavior of concrete and the initiation and propagation of mesoscopic damage. Finally, through the parametric study, the effect of different model parameters on the macro-mechanical properties of concrete is illustrated. In a word, the model can provide support for mesoscopic numerical test of concrete.