HARDENED MATERIAL OF GYPSUM FOR BUILDING MATERIAL AND ITS PRODUCTION

摘要

PURPOSE:To obtain a hardened material of gypsum having high strength, high rigidity and of which desired size and shape is readily obtainable by blending hemihydrate or anhydrous gypsum with a resin including water required for hydration of gypsum and then compression molding it. CONSTITUTION:Hemihydrate or anhydrous gypsum (e.g. chemical gypsum prepared as by-product) is blended with 0.2-4.0wt.% resin (e.g. water-absorptive resin) including 1.0-1.5 times as much as a theoretical amount of water required for hydration of gypsum, optionally various kinds of reinforcing agents and then compression molded by using an ordinary compression molding machine under 30-400kgf/cm<2> to give a hardened maternal of gypsum having 80-400kgf/ cm<2> flexural strength and 1.5-2.2 specific gravity.