Patent ID: 6780237
Filing Date: 2004-08-24
Classification: C04B

Abstract:
A settable composition comprising(i) a cementitious composition comprising the following components: (a) at least 25% of a reactive cement having a CaO to Al2O3 or (Al2O3+X) ratio of greater than 1:1, where X is SO3, SiO2 or Fe2O3; (b) from 0 to 10% of lime; and (c) from 5 to 70% of calcium sulphate, and where the sum of (b) and (c) is at least 15%, the % being by weight based on the combined weight of (a), (b) and (c) and where the proportions of the components are such that the composition on hydration is capable of absorbing at least its own weight of water; and (ii) an aqueous emulsion of an organic polymer, the amount of (ii) in relation to (i) being such as to provide a weight ratio of polymer solids to combined weight of (a), (b) and (c) of from 0.5:1 to 10:1; or (iii) an organic polymer in the form of a powder dispersible in water and where the amount of organic polymer is such as to give a weight ratio of polymer solids to combined weight of (a), (b) and (c) of from 0.5:1 to 10:1; and wherein the proportions of the components are selected from within the above defined ranges to provide a composition which on hydration will have a tensile strength at 4 hours of at least 135 psi and an elongation at 7 days of at least 20%.