Patent ID: 9630880
Date: 2017-04-25
CPC Classifications: B28B,C04B

Claim:
1. A method for producing a cast concrete product from a cement aggregate composition, said method consisting of the following steps: a) milling a mass of red dune sand to reduce the particle size to 45 microns or less; b) providing a mass of Portland cement; c) mixing 70 parts Portland cement to 30 parts red dune sand with reduced particle size; d) providing a mass of other fine aggregate having a nominal particle size of 5 mm, and coarse aggregate having a nominal particle size of about 20 mm, water, and a superplasticizer selected from the group consisting of polycarboxylate ether, polycarbonate, alkyl citrates, sulfonated naphthalene, sulfonated alene, sulfonated melamine, and formaldehyde; e) mixing the Portland cement and red dune sand with the other fine aggregate, coarse aggregate, water, and superplasticizer to produce a mass of concrete including 350 kg/m f) casting the mass of concrete in a shape by placing the cement mix in a mold to produce a molded article; g) within 24 hours of casting steam curing the molded article for 12 hours under atmospheric pressure; h) steam molding the molded article by placing the molded article inside a curing chamber and maintaining 100% humidity in the curing chamber; i) raising the temperature in the curing chamber to about 180° C. within 1 to 2 hours to thereby raise the pressure to 10 bars and maintaining the 180° C. temperature at 100% humidity within the curing chamber for 4 to 5 hours. j) releasing the pressure to reach atmospheric pressure within 20-30 minutes and the temperature reduced; and k) removing the cast product from the curing chamber.