Résumé
In this study a numerical approach to simulate elastic behavior of lightweight concrete, is presented, at mesoscopic level. Concrete is considered as a bi- phasic material, composed of a granular skeleton dispersed in a mortar. Aggregates generation should respect a granular model. A numerical concrete sample is carried out, using three-dimensional finite element mesh. Here lightweight concretes are considered, with Youngs modulus of natural sand based mortar is higher than the modulus of the lightweight coarse aggregates. Different concretes are carried out, according to experimental studies from literature, in order to distinguish the influence of the Youngs modulus contrast, and of the concrete compacity, on mechanical behavior. After a prediction of the equivalent Young's modulus, numerical compressive tests are realized until an experimental value of compressive strength, in order to propose a rupture mode of concrete, and predict a compressive strength.