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:
May. 20, 2010
Takayuki Higuchi, Itoigawa, JP;
Taiichiro Mori, Itoigawa, JP;
Hideaki Ishida, Itoigawa, JP;
Ryoetsu Yoshino, Itoigawa, JP;
Minoru Morioka, Itoigawa, JP;
Takayuki Higuchi, Itoigawa, JP;
Taiichiro Mori, Itoigawa, JP;
Hideaki Ishida, Itoigawa, JP;
Ryoetsu Yoshino, Itoigawa, JP;
Minoru Morioka, Itoigawa, JP;
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
The invention provides an expansive material that allows for large expansion of concrete at a material age of 2 to 7 days after pouring and permits concrete to have higher initial compressive strength and makes sure good storage stability, and a process for preparing that expansive material. The invention provides an expansive material and a process for preparing that expansive material, characterized in that clinker or pulverized clinker containing free lime, a hydraulic compound and calcium sulfate anhydrite is heat treated in a carbon dioxide gas atmosphere to form calcium carbonate in it. Preferably, the expansive material contains a particle in which the free lime, hydraulic compound, calcium sulfate anhydrite and calcium carbonate are all present; the content of calcium carbonate is 0.5 to 10% by mass; and the expansive material has a Blaine's specific surface area of 1,500 to 90,000 cm/g. The expansive material is blended with cement into a cement composition. The preparation conditions are preferably a carbon dioxide gas flow rate of 0.01 to 0.1 L/min. and a temperature of 200 to 800° C., under which conditions there is calcium carbonate formed.