Cement composition
AssigneeFosroc International Limited
InventorsJames Beale, Peter S. Mills
Life of this patent
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Abstract
A hardened cement is prepared by mixing together two slurries, one comprising water and a cement component and the other comprising water, beta anhydrite and calcium oxide and or calcium hydroxide. According to the invention the cement component of the first slurry comprises ferrite and C.sub.12 A.sub.7 or A.sub.7 A--CX.sub.2 (where X is a halogen atom) and a reactive source of silica.
Claims14
A two part composition for use in making a hardened cement, the composition comprising first and second slurries, the first slurry comprising water, a reactive source of silica and a cement component, the cement component comprising the phases ferrite and C.sub.12 A.sub.7 or ferrite and C.sub.11 A.sub.7 CX.sub.2 (where X is a halogen), the phases making up at least 50% by weight of the cement component, the reactive source of silica being present in a weight ratio of 0.1 to 0.6:1 of the cement component, the second slurry comprising water, beta anhydrite, and a calcium compound selected from the group consisting of calcium oxide and calcium hydroxide.
A dried powder formulation comprising a reactive source of silica and a cement component consisting essentially of ferrite and C.sub.12 A.sub.7 or ferrite and C.sub.11 A.sub.7 CX.sub.2 (where X is a halogen atom) and wherein said reactive source of silica is present in a weight ratio 0.1 to 0.6:1 of the cement component.
A method of making a hardening cement, the method comprising mixing together first and second slurries, the first slurry comprising water, a reactive source of silica and a cement component, the cement component comprising the phases ferrite and C.sub.12 A.sub.7 or C.sub.11 A.sub.7 CX.sub.2 (where X is a halogen), the phases making up at least 50% by weight of the cement component, the second slurry comprising water, beta anhydrite, and a calcium compound selected from the group consisting of calcium oxide and calcium hydroxide.
A method according to claim 18, including adding the quantity of the calcium compound in the second slurry in a ratio of from about 4% to about 8% by weight of the cement component.
A method according to claim 18, including adding a partially water soluble calcium sulphate in a concentration in the second slurry of about 1% to about 6% by weight.
Dependencies are inferred from the claim text.