A large amount of flyash from the coal combustion is produced. About 55% of flyash in Japan is now utilized and the remains are dumped at disposal sites; however, the life of these sites is limited. Therefore, in this study, an effort was made to analyze the lining materials by applying flyash cement as a part of its recycle and utilization. When flyash is added to Portland cement, the same kinds of oxides as those of the cement are added. As an injection component, flyash acts, in part, as a fine aggregate which has similar function to fine debris materials of slake-prone rock and, in part, as a binding component.
From these points of view, in order to clarify to what degree the flyash content affects the properties of the lining materials, some different combinations of flyash, Portland cement and water were considered by means of several laboratory experiments, such as a fluidability test, unconfined compressive test, slaking index test and so on. Also, the utilization of flyash as backfilling materials in the mining engineering fields by means of laboratory testing and a numerical method was applied to analyzing the slake-prone rock slope stability when the mixtures are implemented as lining materials of the embankment.