Moisture transport and storage coefficients of porous mineral building materials

Basis of reliable moisture behaviour calculations for building components is - beside the right choice of driving potentials and the implementation of the algorithms - the use of physically correct materials properties. For the determination of these hygric material properties measurement equipments, most of them used for the first time in building research, have been built up. Now the continuos moisture storage function covering the entire range from dry state to capillary saturation can be completed by the use of pressure plate measurements for porous materials. It can also be shown that, despite the general opinion, the vapour diffusion resistance of mineral hygroscopic materials is not a function of sorption moisture content. Furthermore width the aid of a NMR-equipment it has been found that different transport coefficients have to be used for liquid absorption and redistribution. Numerous applications have demonstrated that the moisture behaviour of building components calculated by use of these material properties corresponds well with measured results.