Dry castable concrete compositions and methods of preparing and dry casting the same
AssigneeW. R. Grace & Co.-Conn.
InventorsNeal S. Berke, Samuel F. Heleba, Mario A. Tamez
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Abstract
Dry castable concrete compositions having improved strength and resistance to aggressive chemicals are provided. The compositions comprise water, hydraulic cement, fine and coarse aggregate, and condensed silica fume, wherein the weight ratio of condensed silica fume to hydraulic cement is about 0.10 to 0.25, the water to cement weight ratio is about 0.18 to 0.33, and the mix has a slump of about 1/2 inch or less. Also provided is a method of preparing the dry castable compositions using aqueous condensed silica fume slurries and a method of dry casting the compositions.
Claims21
A method for preparing dry concrete mix for use in dry casting methods comprising the steps of:
- mixing hydraulic cement, fine aggregate, and coarse aggregate;
- adding to the mixture an aqueous slurry of condensed silica fume comprising at least about 5 pounds of condensed silica fume per gallon of slurry, said slurry being added in an amount which provides a condensed silica fume to hydraulic cement weight ratio of about 0.10 to 0.25 and a water to hydraulic cement weight ratio of about 0.18 to 0.33, based on the total amount of water in said concrete mix, to provide a dry concrete mix having a slump of 1/2 inch or less as measured by ASTM C-143.
A method for preparing a cast concrete structure having improved strength and chemical resistance comprising the steps of:
- shaping by a dry casting method, into the form of the structure, a dry concrete mix comprising water, fine aggregate, coarse aggregate, hydraulic cement, and an aqueous slurry of condensed silica fume, wherein the water to hydraulic cement weight ratio is about 0.18 to 0.33 and the condensed silica fume to hydraulic cement weight ratio is about 0.10 to 0.25, said mix having a slump of 1/2 inch or less as measured by ASTM C-143;
- removing the casting form from the cast mix;
- and
- permitting the cast mix to cure.
Dependencies are inferred from the claim text.