Cement composition
AssigneeWestvaco Corporation
InventorFrank J. Ball
Life of this patent
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Abstract
A portland cement product with or without added gypsum is described in which carbon dioxide gas has been homogeneously reacted with the cement slurry during the water-cement mixing. The use of carbon dioxide in an amount from 0.1% to 6.0% by weight of ground cement controls setting and also results in hydraulic cement mixes which are more stable following hydration. The portland cement mixes of this invention may also include the addition of certain acids or acid/salts in amounts sufficient to improve fluidity and accelerate hydration and hardening of the cement products, in amounts from 0.1% to 5.0% by weight of said ground cement. Lignosulfonates and other water reducers may also be added.
Claims17
A portland cement mix comprising, a ground portland cement with or without added gypsum, aggregate, sufficient water to effect hydraulic setting of the cement, and having added thereto carbon dioxide in an amount sufficient to control setting of the mix and stabilize the hydrated cement.
A portland cement mix comprising;
- a ground portland cement with or without added gypsum, aggregate, sufficient water to effect hydraulic setting of the cement,
- having added thereto carbon dioxide in an amount sufficient to control setting of the mix and stabilize the hydrated cement, and
- having added thereto an acid or acid-salt in an amount sufficient to accelerate hydration of the silicates.
A portland cement mix including a ground portland cement with or without added gypsum, aggregate, sufficient water to effect hydraulic setting of the cement, and have added thereto the following;
- a. carbon dioxide in an amount sufficient to control setting of the mix and stabilize the hydrated cement,
- b. an acid or acid-salt in an amount sufficient to accelerate hydration of the silicates, and
- c. a water-reducer in an amount sufficient to reduce the water needed to effect hydraulic setting.
The method for making cementitous articles comprising the steps:
- a. mixing predetermined quantities of ground portland cement which include tricalcium aluminate with water to form a hardenable, fluid slurry;
- b. contacting the fluid slurry with at least 0.1 percent gaseous carbon dioxide (by weight of the portland cement) to control the fluidity characteristics of the slurry and to retard setting of the cement;
- and
- c. casting the slurry into an article having improved dimensional stability after setting.
Dependencies are inferred from the claim text.