Modelling of the transition zone porosity

The ion diffusion process in mortar is different from the one which occurs in cement paste. This difference is due to the presence of transition zones, which take place around the grains in mortar and which are very porous regions. Based on mercury intrusion porosimetry experimental data and on the analysis of percolation through a 3D mortar model, a computation of the transition zone porosity and of the bulk paste porosity has been carried out. The porosity of the transition zone has been analyzed as a function of the mortar composition and of the degree of hydration.