Meso-scale simulation of concrete multiaxial behaviour

Abstract

Concrete is a heterogeneous structural material whose constitutive behaviour is strictly depending on the mechanical properties of the aggregates and the mortar. Its behaviour is often macroscopically characterised by assigning homogenised mechanical properties. A number of methods are devoted to the prediction of the mechanical properties of the composite material by means of meso-scale analysis. The paper concerns a new meso-scale model of cementitious materials. The numerical description of the meso-scale structure is attained using a random method that allocates at each Gauss point of the finite element discretisation of the Representative Volume Element a specific phase of the mixture: aggregate, mortar and void. Each phase is characterised by a specific constitutive model. The method is tested with numerical simulations of cyclic uniaxial compression tests and of multiaxial compression tests, the latter leading to the generation of a biaxial strength domain, for different values of the confinement pressure, that is found to be in good agreement with concrete experimental domains.