e-mail : adrian.muntean@kau.se

Keywords: Two-scale limit, concrete carbonation

We present a multiscale approach for modelling the carbonation of concrete when one accounts for diffusion processes taking place on two different spatial scales. On the macroscopic scale, carbon dioxideis transported through the network of large capillary pores. On the microscopic scale, local transport and reaction take place in the small pores of the C-S-H gel phase. The processes that take place at the microscopic scale are modelled now within a representative unit cell by assuming an idealised, regular microstructure of the cement paste.

We validate the model against experimental data using a two-scale computational scheme. By means of numerical experiments, we can now tell under which conditions microscopic diffusion effects can play a significant role on the speed of the carbonation process