Mathematical model and numerical method for simulation of coupled chemo-thermo-hydro-mechanical process in concrete subjected to fire

A hierachical mathematical model for analyses of coupledchemo-thermo-hydro-mechanical behavior in concretes subjected to fire ispresented. The concretes are modeled as unsaturated deforming reactiveporous media filled with two immiscible pore fluids. The mathematical modelconsists of a set of coupled, partial differential equations governing themass balance of the dry air, the mass balance of the water species, the massbalance of the matrix components dissolved in the liquid phases, theenthalpy (energy) balance and momentum balance of the whole medium mixture.The thermo-induced desalinization process is particularly integrated intothe model. A mixed weak form for the finite element solution procedure isformulated for the numerical simulation of chemo-thermo-hydro-mechanicalbehaviors. Special considerations are given to spatial discretization ofthe hyperbolic equation with non self-adjoint operator nature. Numerical resultsdemonstrate the performance and the effectiveness of the proposed model andits numerical procedure in reproducing the coupled chemo-thermo-hydro-mechanicalbehavior in concretes subjected to fire.