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. 24, 2026
Filed:
Mar. 16, 2022
Taiheiyo Cement Corporation, Tokyo, JP;
The University of Tokyo, Tokyo, JP;
Takahito Nozaki, Tokyo, JP;
Aoi Fukuoka, Tokyo, JP;
Kouki Ichitsubo, Tokyo, JP;
Takayuki Hayakawa, Tokyo, JP;
Takafumi Noguchi, Tokyo, JP;
Dianchao Wang, Tokyo, JP;
TAIHEIYO CEMENT CORPORATION, Tokyo, JP;
THE UNIVERSITY OF TOKYO, Tokyo, JP;
Abstract
Provided is a method of producing a roadbed material from which less hexavalent chromium leaches out through use of a crushed product of a cementitious hardened body containing hexavalent chromium as a raw material. The method includes a carbonation treatment step of subjecting the crushed product of the cementitious hardened body to carbonation treatment with a carbon dioxide-containing gas having a temperature of 50° C. to 140° C. and a water content of 1.5% or more to obtain the roadbed material from which less hexavalent chromium leaches out than before the treatment. Preferably, the method includes, before the carbonation treatment step, a crushing step of crushing the cementitious hardened body to obtain a crushed product consisting of grains having a grain size of 100 mm or less at a ratio of 50 mass % or more and a grain size of 2.36 mm or less at a ratio of 1 mass % or more.