Numerical Determination of Permeability in Unsaturated Cementitious Materials

Abstract

To assess durability of cement-based materials, permeability is commonly considered as an important indicator. It is defined as the rate of movement of an agent (liquid or gas) through the porous medium under an applied pressure. Although permeability can be directly measured in laboratories, these experimental tests generally require specialized equipment and long periods of time to be completed, so they are laborious and expensive. For economic and ecological interests, numerical models are considered as an attractive alternative. Up until now, however, permeability of virtual cement seems to exceed experimental data by several orders of magnitude. Full saturation however, as generally assumed in numerical evaluations, does not realistically represent the experiments. Modelling fluid flow through unsaturated cement-based materials constitutes the focal point of this thesis. It is shown that the saturation degree has a significant effect on the permeability.