Investigation of moisture transport properties of cementitious materials

This paper is focused on two ways to enhance our understanding of moisture transport properties of cementitious materials. The first one utilizes a multi-phasic moisture transport model to adjust the permeability through the fitting of measured mass loss curves during a drying experiment. In the second one, measured apparent diffusion coefficient curves vs. relative humidity (RH) are fitted by a general expression which includes both liquid transport and vapour diffusion. Due to different RH ranges of predominance of liquid and vapour transport, the permeability and vapour diffusion coefficient can be determined separately. Three cement pastes, whose properties are collected from the literature, are analysed by means of those two methods. Discussions on relative permeability and Knudsen diffusion show a significant influence on the modelling of moisture transport. A further comparison with measured permeability data found in the literature is able to provide a deeper understanding of moisture transport properties.