Low density cementitious building products

摘要

Provided is a method of forming a cementitious product comprising mixing a cementitious material with a siliceous material and a low bulk density material with water to form a slurry, forming a green shaped article from the slurry and curing the article in an autoclave, is claimed. The low bulk density is substantially calcium silicate hydrate which is preferably obtained by reacting a calcareous reactant with a siliceous reactant. The siliceous reactant maybe in the presence of water at an elevated temperature with at least 90 weight % of the siliceous material having a particle size of less than 100 microns. Optionally the material can also include 0-25 % of fibrous material and 0-40 % of other additives. The resultant cementitious product is suitable for internal and external applications.