Abstract: A method and composition for making concrete includes an antifreeze admixe which is added to the concrete to prevent the freezing of water in the concrete when the concrete is cured during the winter or other cold conditions. The concrete admixture includes sodium nitrate and sodium sulfate combined with one another in a predetermined ratio. In a preferred a embodiment the ratio of sodium nitrate to sodium sulfate equals 3:1. A dosage of greater than 2% by weight of cement of the above described admixture was found to significantly increase the compressive strength of concrete cast of cold (below freezing, or 0 degrees celsius) temperatures, and dosages of 6% and 8% by weight of cement of the specified admixture were found to be particularly effective.
Type:
Grant
Filed:
May 11, 1993
Date of Patent:
March 22, 1994
Assignee:
The United States of America as represented by the Secretary of the Army