Bedeutung der Porosität für die Eigenschaften von Gipserhärtungsprodukten

The importance of porosity for the properties of hardened gypsum plaster products. The porosity of the plaster matrix plays a central part in the mechanical properties of gypsum plaster building components. It correlates with the various properties (ME) through a function of the type: n ME =(1-p) for n = 2,5...3,5 in wich K is a material constant for the pore-free state (p = 0). Normal commercial gypsum plaster building components wich are made from _-hemihydrate binders habe porosities between 0,45 and 0,55. The corresponding property values can be improved by a factor of more than 3 by halving the porosity. However, practical implementation of these results requires different production processes which will allow the water/plaster ratio to be lowered to values around 0,3. Water/plaster ratios of < 0,25 have already been achieved on an experimental basis. For the same porosity gypsum plaster products made from a- and -hemihydrate have practically the same mechanical properties.