Determination of geometrical parameters of the microstructure of a porous medium: Application to cementitious materials

Mass transfer in porous media is governed, besides the species diffusion coefficient, by the porosity and the geometrical parameters of the materials microstructure. This paper aims at developing a methodology for the determination of tortuosity and constrictivity factor based on a diffusion modeling in a porous medium of neutral species. Tortuosity was obtained by the computation of particles trajectory. After which, constrictivity was deduced from the formation factor, represented by the relative diffusion coefficient. Results show that tortuosity evolves in the opposite direction that the porosity while constrictivity evolves in the same direction. In addition, both parameters further slowdown the transfer for lower porosities.