Calcium aluminate cements

Calcium aluminate cements are cements consisting predominantly of hydraulic calcium aluminates. Alternative names are 'aluminous cement', 'high-alumina cement' and 'Ciment fondu' in French. They are used in a number of small-scale, specialized applications. Calcium aluminate cements are cements consisting predominantly of hydraulic calcium aluminates. Alternative names are 'aluminous cement', 'high-alumina cement' and 'Ciment fondu' in French. They are used in a number of small-scale, specialized applications. The method of making cement from limestone and low-silica bauxite was patented in France in 1908 by Bied of the Pavin de Lafarge Company. The initial development was as a result of the search for a cement offering sulfate resistance. The cement was known as 'Ciment fondu' in French. Subsequently, its other special properties were discovered, and these guaranteed its future in niche applications. The main active constituent of calcium aluminate cements is monocalcium aluminate (CaAl2O4, CaO · Al2O3, or CA in the cement chemist notation). It usually contains other calcium aluminates as well as a number of less reactive phases deriving from impurities in the raw materials. Rather a wide range of compositions is encountered, depending on the application and the purity of aluminium source used. Constituents of some typical formulations include: