Gypsum hydration: a theoretical and experimental study

Calcium sulphate dihydrate (CaS04'2HzO or gypsum) is used widely as building material because of its excellent fire resistance, aesthetics, and low price. Hemihydrate occurs in two formations of a- and b-type. Among them b-hemihydrate is mainly used to produce gypsum plasterboard since the hydration product of the a-hemihydrate is too brittle to be used as building material /10/. This article addresses the hydration of hemihydrate since it detenrmines the properties of gypsum and it is influenced strongly by water and the properties of hemihydrate. The microstructure development of gypsum during hydration is investigated. The influence of water is studied from its effect on fresh behavior and void fraction of the gypsum