Numerical Simulation of Sorption-desorption Isotherme for Cement based materials

摘要

One of the most important issues in civil engineering about structures is their durability. A structure during his lifetime faces different environmental situations, like different relative humidities, and different cycles of drying and saturation will be imposed on it, so it is very critical to characterize materials behavior against these changes. Some informations are needed to predict it, one of these informations is desorption and sorp-tion isotherm. In cement based materials just as cement paste, there remain generally extremely fine pores, consequently obtaining isotherms experimentally is considered as a substantially time-consuming experience. Therefore, it is of interest to model the isotherm from a numerical point of view. This physical phenomenon has been a field of study of intense researches, however, there are not many models relying on true physical effects which take place during drying and saturation. In the present work, in order to model a porous media, a numerical morphology of the geometry of the porous media has been presented by means of a random field excursion through the selection of a random field and a threshold. Random field parameters are defined based on experimental values. Once the porous media has been reproduced, the morphological analysis must be done in order to model water transfers.