Application of the periodic homogenization technique to ionic transfer in cementitious materials.
Résumé
In this paper we propose two macroscopic models of ionic transfer in saturated porous media. These models are established by using periodic homogenization technique for two regimes of transfer (weakly or strongly accelerated). For each regime of transfer, the associated macroscopic model obtained (pure migration or coupled diffusion-migration model) depends on the order of magnitude of the dimensionless numbers characterizing the transfer naturally introduced. Oppositely, the associated homogenised diffusion tensor is identical in the two cases of transfer considered; it depends only on the geometrical complexity of the microstructure of the porous medium. Finally numerical simulations are carried out on periodic porous media in order to calculate the corresponding homogenized diffusion tensor and to compare it with experimental results for the case of chlorides in cementitious materials.