Produsing gypsum product with improved properties by using additives

The aim of this paper is to produce gypsum product with improved properties. At first the building material with the mixture of gypsum and various additives are tested according to the standard conditions (ASTM test 1369). Absorbed water and cold crushing strength ware measured. Regarding the results, the used additive materials were divided into two branches for decreasing the density and increasing the strength. Samples were studied by choosing one of additives mainly and the effect of the ther were divided into two branches for decreasing the density and increasing the strength. additive considered. XRD and SEM studies were performed. Isinglass improved the properties, but decreased the hydration rate, which could be partly improved by sodium chloride. The best composition was 100 g gypsum, 15 g cement, 5g pulp, 15 g isinglass and 20 g sodium chloride.