| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 6479168 | Building and Environment | 2017 | 9 Pages |
â¢An analytical model describing the moisture absorption in a capillary building material is proposed.â¢A closed form equation relating the water uptake coefficient to the diffusivity is derived.â¢A good agreement with the measured data and with a numerical solution is found.â¢A novel method for the inverse determination of the diffusivity is proposed.
Isothermal absorption of moisture in a semi-infinite porous body is described with a diffusion law as a free boundary problem in which the porous domain is divided into a nearly saturated and a nearly dry region. This problem is solved via an analytical approach by assuming the diffusivity as a step function of the volumetric water content. The analytical solution is then applied to modeling the behavior of two real building materials during a water uptake test. It is shown that the model is able to explain the absorption process adequately, and that a good agreement with the measured data is obtained. Finally, a novel method for the inverse determination of the diffusivity via water uptake tests is proposed.
