Plaster (hydrated calcium sulfate) it's an air binder, obtained by roasting gypsum stone in calciners and grinding it. Due to the quick setting time of the gypsum grout, (2 – 15 min), mineral or organic retarders are used. Ready-made gypsum mixtures packed in bags are commercially available: designed to be mixed with water: smooth, plasters, fillers.
Due to the grain size, we distinguish two types of gypsum: GB-G – coarsely ground gypsum and GB-D -finely ground gypsum
Two types of gypsum binders are produced: ordinary and special
• Ordinary building gypsum is used for decorative plasters and for auxiliary construction works.
• Special gypsum binders include: gypsum glue, gypsum putty and plaster plaster. They are used for gluing gypsum prefabricated elements, plastering plaster elements (np. plasterboards), preparation of mortars and interior plasters.