(From left) IGARI Momoka and IIDA Minori
IGARI Momoka, a first-year master’s degree student in the Agricultural Chemistry Program, Graduate School of Agriculture, and IIDA Minori, a fourth-year student in the Department of Agricultural Chemistry, School of Agriculture (both from the Laboratory of Soil Science), received the Outstanding Paper Presenter Award at the 60th Japan National Conference on Geotechnical Engineering held in July 2025 (number of published papers: 1,124).
Formation of early-hardening additives and initial hydrates in cement-bentonites assuming filling materials for underground structure removal holes (IGARI Momoka)
In urban redevelopment projects, it is necessary to remove existing underground structures. As holes are formed in the ground during removal, filling materials (cement-bentonites: CB) must be injected to fill the holes. The strength of CB may be adjusted by adding materials. This study attempted to clarify the strength development mechanism of the material-added CB at the initial material age. As a result, it was found that the initial strength differs for each material owing to differences in the hydrates formed during the initial material age.
Relationship between the strength of geopolymer solidified bodies using municipal solid waste incineration bottom ash and the elemental leaching (IIDA Minori)
Geopolymers are materials formed by the reaction between materials containing amorphous aluminum silicates and alkaline solutions followed by hardening. They are gaining attention as a cement substitute for reducing CO2 emissions. However, since the strength development mechanism of geopolymers is complicated, this study attempted to clarify the relationship between the strength of geopolymer solidified bodies using municipal solid waste incineration bottom ash and the amount of elemental leaching. As a result, it was found that the strength increases when the amount of Si and Ca leaching is high.