Pore Structure Parameters and Drying Rates of Building Materials

Abstract

Experimentally obtained courses of drying for representative porous building materials were investigated. With use of analytical and numerical solutions of the diffusion equation the moisture transport parameters of the materials were identified from the experimental data and modelled in relation to the parameters of their pore structure. The capillary models of moisture diffusivity based on the pore size distribution of given material were used in this analysis. It was confirmed that the character of drying rates specific both for their constant and falling periods is dependent on combination of only a few important pore structure parameters specific for each material. In concordance with the capillary models the pore volumes equivalent to critical degrees of water saturation during drying as the critical moisture content, the capillary moisture content and the full saturation are in a correlation with the drying rates and can serve as indicators of the actual evaporation potential of given material.