Desaturation-resaturation in argillite rock subjected to ventilation

This paper presents the characterization of the mass transfer process in Bure argillite, in terms of moisture diffusivity as a function of relative humidity. A thin plate and a hollow cylinder samples are set in a tight box in which relative humidity is imposed. The samples mass is continuously recorded. A diffusivity identification method is proposed for the case of axial and radial diffusions. This method is based on the measured mass evolution, when the diffusivity is assumed to be constant during each desorption and adsorption step. A significant non-linearity and a high hysteresis are observed, during the desorption-adsorption process.