Hardening mechanism and time on silica-based solidifying material as ground improvement material

Past research has developed a powdery silica-based admixture of inorganic waste containing a large amount of silica component such as a waste glass and a fly ash. It is effective as a solidifying material by mixing with a blast furnace slag. In addition, it can be expected to have superior characteristics as well as high strength as compared with cement-based solidifying material, and it is effective to adapt to soil improvement. In this study, in order to elucidate the solidification mechanism, energy dispersive X-ray analysis (EDS analysis), scanning electron microscope observation (SEM observation) and X-ray diffraction analysis (XRD analysis) have been conducted. In addition, in order to control the solidification time, blast furnace cement or normal Portland cement or calcium hydroxide (Ca(OH)2) is partially or completely substituted for the blast furnace slag which is the raw material of the mixed solidifying material. On the contrary, the uniaxial compression test, and the flow test are carried out to investigate the usefulness and solidification mechanism in view of practical application.