Multiscale/Multiphysics Model for Concrete

In this paper a general model for the analysis of concrete as multiphase porous material, obtained from microscopic scale by applying the so-called Hybrid Mixture Theory, is presented. The final formulation of the governing equations at macro-level is obtained by upscaling their local form from the micro-scale. This procedure allows for taking into account both bulk phases and interfaces of the multiphase system, to define several quantities used in the model and to obtain some thermodynamic restrictions imposed on the evolution equations describing the material deterioration. Two specific forms of the general model adapted to the case of concrete structures under fire and to the case of concrete degradation due to the leaching process are shown. Some numerical simulations aimed at proving the validity of the approach adopted, are also presented and discussed.