Butadiene-styrene copolymer-cement composition and method of preparation

A cement composition comprising a mixture of Portland cement, about 5%-25% based on the weight of said Portland cement of styrene-butadiene-1,3 copolymer having a styrene to butadiene weight ratio of about 30:70 to 70:30, water in amount not in excess of about 40% based on the weight of said Portland cement, and, based on the weight of said copolymer, (a) 2%-10% of non-ionic surfactant of the group consisting of fatty acid esters, acid derivatives of ethylene oxide, condensation products of ethylene oxide with alcohols, condensation products of ethylene oxide with phenols, condensation products of ethylene oxide with alkyl phenols, and mixtures of said non-ionic surfactants, (b) 1%-7.5% of anionic surfactant from the group consisting of alkyl aryl sulfonates, sulfate derivatives of fatty alcohols of 9-17 carbon atoms, sulfonated animal oils, sulfonated vegetable oils, and mixtures thereof provided however that at least 15% of said anionic surfactant is a sodium alkyl sulfate in which the alkyl group contains 9-17 carbon atoms, and (c) [1%- 5% of polymethylsiloxane fluid], about 2.5% of a polymethylsiloxane emulsion containing 29% of the polymethylsiloxane the sum of (a) and (b) not exceeding about 11% by weight of said copolymer, and the weight ratio of (a) to (b) being within the range of about 0.7:1 to 10:1.

A method for making a cement composition which comprises intimately mixing Portland cement, mineral aggregate, a dispersion of styrene-butadiene-1,3 copolymer having a styrene to butadiene weight ratio of about 30:70 to 70:30, water in an amount not in excess of about 40% based on the weight of said Portland cement, and, based on the weight of said copolymer, (a) 2-10% of non-ionic surfactant, (b) 1-7.5% of anionic surfactant, at least 15% of which is a sodium alkyl sulfate in which the alkyl group contains 9-17 carbon atoms, and (c) [1-5% of] polyorganosiloxane fluid surfactant in an amount equal to about 2.5% of a polyorganosiloxane emulsion containing 29% of the polyorganosiloxane , the sum of (a) and (b) not exceeding about 11% by weight of said copolymer and the weight ratio of (a) to (b) being within the range of about 0.7:1 to 10:1.