Adhesive Strength of Gypsum Composites with Lightweight Fillers

Gypsum composites with several types of lightweight fillers were studied. Gypsum starts to be more important material nowadays, because it is one of the most environmentally friendly building binders. Therefore, there are new ways of the larger utilization of gypsum based materials to be sought. Even though the use of fillers in the gypsum is generally not necessary, because gypsum (opposite to cement or lime) does not shrink, fillers can be used for economic reasons or to improve some other properties of the gypsum material, e.g. thermal or fire resistance. We studied the adhesive strength of gypsum composites, containing three types of lightweight fillers (perlite, expanded clay aggregate and recycled PUR) and compared them with the properties of gypsum mortar with siliceous sand. It was found, that the type of the filler has principal impact on the adhesive strength of the gypsum composite.