The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 04, 2014
Filed:
Oct. 24, 2011
Takayuki Higuchi, Itoigawa, JP;
Tsutomu Kida, Itoigawa, JP;
Ryoetsu Yoshino, Itoigawa, JP;
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
The invention provides a cement admixture that improves the ability of concrete to bring about high initial strength, works in favor of enhancing the effect on hexavalent chromium reductions, and is less likely to decrease in the effect on hexavalent chromium reductions even upon storage as well as a method for reducing hexavalent chromium. The invention is embodied as (1) A cement admixture, characterized by comprising an expanding material containing free lime, a hydraulic compound and calcium sulfate anhydrite, and a tin sulfate-containing substance; (2) The cement admixture according to (1), characterized in that the tin sulfate-containing substance is contained in an amount of 0.2 to 8 parts by mass—as calculated on a tin sulfate basis—in a total of 100 parts by mass of the expanding material and the tin sulfate-containing substance; (3) The cement admixture according to (1) or (2), characterized in that the expanding material has been treated with carbon dioxide gas to form calcium carbonate therein; (4) The cement admixture according to any one of (1) to (3), characterized in that the expanding material has been surface treated with a shrinkage reducer; (5) A cement composition, characterized by containing cement, and the cement admixture according to any one of (1) to (4); and (6) A method for reducing hexavalent chromium, characterized by use of the cement composition according to (5).