MODELING OF MOISTURE TRANSPORT IN EARLY-AGE CEMENT PASTE

The existing approaches to modeling the moisture transport in early-age cement paste are based on the Richards equation, the key parameter of which is the moisture diffusion coefficient. To compute it, it is necessary to find expressions that link capillary pressure with the moisture content in the pore medium. For these purposes, the phenomenological models of van Genuchten are most often taken. The approach like that is not efficient, since such phenomenological models call for experimental data for fitting the necessary parameters. In this article, instead of the phenomenological models of Van Genuchten, it is proposed to use the thermodynamic equilibrium conditions in the pore medium based on the size pore distribution of cement paste, constituting it from a single structural parameter, an approximate estimate that can be received from existing computational models of the microstructure development of cement paste, which makes it possible not to carry out experimental researches for fitting the necessary parameters.