2015 年 1 巻 4 号 p. 1-6
Technologies for the effective use of coal ash generated from coal power plants as construction materials have been making great progress due to growing interest in achieving a sustainable materials-cycling society. However, among the different kinds of coal, which is the raw material of coal ash, there are those that elute hazardous substances in excess of the environmental soil quality standards. To control the elution of such hazardous substances, coal ash is solidified. There are few examples which have investigated change in the amount of hazardous substance elution, or intensity over a long period of time with respect to coal ash solidified with cement. Thus, the authors have been continuously measuring the strength of embankments made from solidified coal ash and the elution quantities of hazardous substances. Such measurements show that, in some cases, the strength of solidified coal ash decreases in the long term. It is also found that solidification can lower the levels of some hazardous substances to below the environmental standard value. However, it is also found that even with solidification, elution quantities of some of hazardous substances can exceed the standard value over time.
