Applicability of Additives for Ground Improvement Utilizing Fine Powder of Waste Glass

Abstract

As a solidifying material for ground improvement using inorganic waste as a raw material, the authors have been developing an additive mixture of the fine powder of waste glass containing a large amount of silica generated during the production of glass cullet and an alkaline aid (heat-treating type of “Earth-Silica; ES” additive). Furthermore, a solidifying material that solidifies by mixing this additive with the fine powder of blast furnace slag, which is a by-product of steel production, is also being developed. In this study, the authors reviewed the mixing process of the solidified materials, especially the one made with the heat-treating type of ES additive, omitting the heat treatment of the fine powder of waste glass and the alkaline aid and applying only the mixing treatment. As a result, a mixing type of ES additive was manufactured to simplify the manufacturing process, and the difference in the performance of the solidifying material, depending on the presence or absence of the heat-treating process during the additive manufacturing, was verified in terms of the effect on the solidifying action. Specifically, the solidifying materials to which the heat-treating type of ES additive and the mixing type of ES additive were added, respectively, were applied to the high-pressure injection stirring method, one of the ground-improvement methods. Various tests clarified the changes in viscosity of these solidifying materials over time and the acceleration of their solidifying rates when adding ordinary Portland cement separately.

Numerical Analysis for Ground Subsidence Caused by Extraction Holes of Removed Piles

“…Previous studies have shown that ground subsidence can be prevented and that the impact of ground subsidence can be lessened by injecting a filler into the extraction holes of removed piles. In addition, it is considered desirable for the filler that is injected into the extraction holes of removed piles to aid in the development of strength so that local subsidence does not occur in the area around the filled holes [15][16][17]. Furthermore, it has also been clarified that the strength of the filler can be developed sooner by mixing sodium carbonate into it [15][16][17].…”

“…In addition, it is considered desirable for the filler that is injected into the extraction holes of removed piles to aid in the development of strength so that local subsidence does not occur in the area around the filled holes [15][16][17]. Furthermore, it has also been clarified that the strength of the filler can be developed sooner by mixing sodium carbonate into it [15][16][17].…”