A meso-scale approach for the modeling of concrete behavior at high temperatures

A thermo-mechanical model at meso-scale for concrete subjected to high temperatures is presented in this paper. The objective is to highlight the effect of concrete's heterogeneity on its behavior, by taking into account its different components and their associated properties in the model adopted. The different components are represented by a heterogeneous mesh composed of two phases: aggregates and cement paste. The numerical results obtained with heterogeneous meshes are compared with those obtained with a homogeneous one and allow to conclude on the effect of strain incompatibility between aggregates and cement paste on the development of cracking. Experimental results from literature are used so as to identify the model parameters and therefore to validate the model. Moreover, the mechanical and thermo-mechanical validation of our heterogeneous approach is also performed using analytical and experimental results.