Roadbed material production method

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.

Dependencies are inferred from the claim text.