An aqueous oil-in-water emulsion containing a propylethoxysilane oligomer mixture or a mixture of a propylethoxysilane oligomer mixture and octyltriethoxysilane in a weight ratio of 3:1 to 1:3, at least one emulsifier or an emulsifier system, at least one content of a 2-aminoethanol and water is used as an addition in the production of hydraulically setting cement mixtures such as mortar, screed or concrete for reduction of the shrinkage characteristics.

A cementitious composition including at least one cementitious material and at least one crack reducing admixture including: (i) from 0 to about 5 weight percent of at least one alcohol, based on the total weight of the admixture excluding water; and (ii) a compound having the chemical structure of formula (III): ##STR00001##
wherein: v is an integer from 0 to 50 and w is an integer from 0 to 50, with the proviso that the sum of v and w is at least 1 but not greater than 50. Also, methods of making the cementitious composition, reducing or eliminating the formation of cracks in a cementitious composition as the cementitious composition cures, and limiting the size of cracks which form in a cementitious composition as the cementitious composition cures using an admixture for cementitious compositions as described herein.

A composition of matter may include a cement precursor, a phosphazene oligomer and water. A method may include blending a phosphazene oligomer and a cement precursor to form a cement precursor mixture. The method may then include introducing water into the cement precursor mixture to form the cement slurry. A composition of matter may include a cured cement matrix having a polyphosphazene polymer distributed throughout the cement matrix. A method may include cementing a wellbore by introducing a cement slurry into a wellbore, where the cement slurry includes a phosphazene oligomer. The method then includes maintaining the cement slurry such that a cured cement sheath forms, the cement sheath having a polyphosphazene polymer.

A method of making a gypsum board including: preparing an aqueous slurry including a mixture of: calcium sulfate hemihydrate, water at a weight ratio of water to calcium sulfate hemihydrate of 0.2:1 to 1.2:1, and on a dry basis per 100 parts by weight (pbw) calcium sulfate hemihydrate: 0.2 to 2 pbw siloxane, 0.01 to 2 pbw siloxane polymerization catalyst including magnesium oxide and optionally fly ash, and 0.01 to 0.2 pbw triethanolamine (TEOA); allowing the siloxane to polymerize to polysiloxane; and depositing the slurry on a first cover sheet and covering the slurry with a second cover sheet to shape the slurry, and allowing the shaped slurry to set to form the gypsum board. Also, disclosed is the gypsum board resulting from the method.

A method of making a gypsum board including: preparing an aqueous slurry including a mixture of: calcium sulfate hemihydrate, water at a weight ratio of water to calcium sulfate hemihydrate of 0.2:1 to 1.2:1, and on a dry basis per 100 parts by weight (pbw) calcium sulfate hemihydrate: 0.2 to 2 pbw siloxane, 0.01 to 2 pbw siloxane polymerization catalyst including magnesium oxide and optionally fly ash, and 0.01 to 0.2 pbw triethanolamine (TEOA); allowing the siloxane to polymerize to polysiloxane; and depositing the slurry on a first cover sheet and covering the slurry with a second cover sheet to shape the slurry, and allowing the shaped slurry to set to form the gypsum board. Also, disclosed is the gypsum board resulting from the method.

A composition of matter may include a cement precursor, a phosphazene oligomer and water. A method may include blending a phosphazene oligomer and a cement precursor to form a cement precursor mixture. The method may then include introducing water into the cement precursor mixture to form the cement slurry. A composition of matter may include a cured cement matrix having a polyphosphazene polymer distributed throughout the cement matrix. A method may include cementing a wellbore by introducing a cement slurry into a wellbore, where the cement slurry includes a phosphazene oligomer. The method then includes maintaining the cement slurry such that a cured cement sheath forms, the cement sheath having a polyphosphazene polymer.