STUDY ON DIFFUSION COEFFICIENTS OF WATER IN UNSATURETED CEMENT MATERIALS UNDER NON-ISOTHERMAL CONDITIONS

Abstract

Water diffusivities of liquid and vapor phase in unsaturated condition of cementitious material under moisture and temperature gradient were algebraically clarified. The diffusivities shown in this study were formulated by using an adsorption isothermal model based on the state equation of thermodynamic. It is possible to reflect microstructural properties such as pore size distribution and pore volume. As an analysis example, the relationship between moisture content and water diffusivities were shown. Furthermore, a nonlinear moisture transfer simulation was performed to examine the distribution characteristics of moisture content derived from the temperature gradient.