Critical moisture content of silicate-based building materials

The critical moisture content is defined as a minimum water amount necessary for the capillary transport. It is determined by the pore structure parameters of a given material and represents one of the material characteristics important for modelling the moisture transport parameters. A difference between the actual and critical moisture contents represents the pore volume relevant for a capillary water flow at a given degree of saturation. In the paper the critical moisture content for various silicate-based building materials was determined from drying tests. The obtained results were analysed by modelling the water absorption coefficient by a power law and correlated with the mercury intrusion porosimetry data.