Heat-insulating gypsum based plaster compositions

Abstract

When developing lightened heat-insulating materials on the base of calcium sulphate (increasingly important in construction) the possibilities to introduce various lightweight aggregates and the limits of their content have been studied [1, 2]. The purpose of this particular study has been to develop the compositions for interior plaster coverings, with fine perlite as basic filler. It is known that entering of perlite grains (of low thermal conductivity) in gypsum matrix can significantly improve heat and sound insulation properties of the composite, with not only its density being lowered, but, unfortunately, its strength as well. To strengthen the composite a part of perlite could be replaced with cenospheres. These hollow alumina-silica microspheres (formed as a part of fly ash) are known as efficient filler due to their form, waterproofness, low density and therma conductivity. The preliminary experiments showed that certain dosages of metakaolin, plasticiser and latex could improve gypsum matrix, structure and properties of the composite.