METHOD FOR PRODUCING CEMENT-BASED SOLIDIFYING MATERIAL, METHOD FOR SOLIDIFYING SOFT SOIL, AND METHOD FOR REDUCING AMOUNT OF HEXAVALENT CHROMIUM TO BE ELUTED FROM SOLIDIFIED SOIL

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a cement-based solidifying material which is obtained by using blast furnace slag fine powder as a raw material and which can satisfactorily reduce the amount of hexavalent chromium to be eluted from the soil thus solidified while keeping solidification intensity even when the cement-based solidifying material is used for solidifying soft soil.SOLUTION: The method for producing the cement-based solidifying material comprises: a first step of mixing cement, gypsum and the blast furnace slag fine powder to obtain the first cement-based solidifying material; and a second step of changing at least a part of the cement and/or blast furnace slag fine powder to be used at the first step into the cement and/or blast furnace slag fine powder, which are/is made different in at least one of the sulfide sulfur concentration, the value of B, and the content of the hexavalent chromium, based on a RS×B/Cr value at the first step, and mixing the changed or unchanged cement, the gypsum and the changed or unchanged blast furnace slag fine powder to obtain the second cement-based solidifying material having the RS×B/Cr value equal to or larger than 45×10.SELECTED DRAWING: None