Nonflammable building material and process for its preparation.

摘要

Disclosed are a nonflammable building material comprising 3 to 20 parts by weight of a finely divided mineral about 10,000 cm<2>/g in Blaine value and 0,3 to 0,8 in apparent density and 100 parts by weight of a mixture admixed therewith and composed of 20 to 60% by weight of a finely divided aggregate wholly passing through a 4-mesh screen and containing not more than 5% of particles of plus 200 mesh size, 1,0 to 7,0% by weight of a pulp, 0.05 to 2,0% by weight of an organic fiber and the balance cement and siliceous sand in a CaO/SiO2 mole ratio of 0,5 - 1,0, and a process for its manufacture comprising the steps of preparing a starting mixture of the above composition, spreading the mixture on a belt conveyor (1) causing water to penetrate into the spread mixture (7,14) shaping the wet mixture under pressure (15) and curing the mixture in an autoclave.