A fractal model of the porous microstructure of earth-based materials

Soils with a clay component have been widely used as construction materials since the earliest times and now it continue to be used in some developing countries and in the so-called bioarchitecture. This paper presents the experimental porosimetric data obtained for 13 different earth-based materials using the mercury intrusion technique. The porous microstructure is geometrically described by means of two models based on fractal geometry, the Menger’ sponge and an original P’ sponge proposed here. The P’ sponge is constructed using an aggregation process of granular components, resembling the formation and texture of soil. The fractal dimension of the experimental data set is determined following Pfeifer and Avnir’s approach. Generally the fractal range spans two to three orders of magnitude, from 20 to 0.02 μm. The results show the P’ sponge to be more representative than the Menger’ sponge.