The comparison of different moisture storage functions in the porous material

The moisture storage function is the basic of achieving the relevant parameters and the transfer coefficients of the moisture transfer equation, and is also the basic of the dynamic analysis. Yet there is no more comprehensive moisture storage data and proper formula to express the moisture storage function. In this paper, the comparison of three kinds of moisture sorption isotherm and one kind of water retention characteristic have been presented along with the experimental data of a new thermal insulation mortar. The data calculated by Gauss model are the closest to the experimental data. The test of significance shows that the fitting of the Gauss model is a good significant level, its squared residuals is 2.89E-4, and the relative errors of most data are less than 3%. So the Gauss model is very appropriate and reliable for expressing the moisture storage function of the building materials.