Abstract :
This paper presents a method of defining mass diffusivity Dm of a porous material, based on non-stationary processes of moisture absorption. The results of testing absorption in 15 cycles, Is–XVs, are presented. The experiment covered series of cement mortars of different water–cement ratio, (w/c=0.50, 0.65, 0.80), and was carried out at three values of temperatures (T=20, 35, 50 °C), at which the testing referred to five selected ranges of relative humidity of air, Δϕ. The testing technique itself and the influence of certain factors on Dm defined by means of t-type calculations were evaluated.
