IE39058L - Hydraulic cement - Google Patents

Abstract

1469273 Treated hydraulic cement RAYCHEM CORP 13 March 1974 [14 March 1973] 11160/74 Heading C1H The open-time plasticity of an hydraulic cement composition is enhanced by uniformly mixing into pulverulent hydraulic cement, without essentially increasing the Blaine surface area thereof, a solution containing an effective opentime plasticity-increasing amount of an additive comprising a condensed naphthalene material selected from condensed naphthalene sulphonic acid, sulphonate or other sulphonic acid derivative, the solution being insufficient in amount to essentially alter the pulverulent appearance of the cement, and ageing the resulting composition for at least 15 minutes. The composition may be further treated with additional free (i.e. not in the solution used for the above treatment) water reducing agents, e.g. condensed naphthalene material and lignin sulphonates (see example 7). The condensed naphthalene material may arise from condensation of naphthalene sulphonic acid, sulphonate or other sulphonic derivative with compounds containing the divalent carbonyl radical, e.g. ethylene urea or aldehydes. In the examples, both aqueous and dimethylsulphoxide solutions are referred to. In Example 9, light weight concrete is prepared from a composition comprising treated cement, optionally Plaster of Paris, ground sand, aluminium powder and hot water. The foamed compositions are then placed in a steam autoclave and pressure gradually increased to afford a steam temperature of about 190‹ C., which temperature is maintained for 16 hours. [GB1469273A]