Chemical resistance, deterioration characteristics, and evaluation for durability of water-absorbent polymer gels used in foundation construction for contaminated ground

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04251
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Shinshu University
• Principal Investigator: Umezaki Takeo 信州大学, 学術研究院工学系, 教授 (50193933)
• Co-Investigator(Kenkyū-buntansha): 河村 隆 信州大学, 学術研究院工学系, 准教授 (50324231)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 汚染地盤 / 杭基礎 / 吸水性高分子 / 流動性 / 摩擦低減 / 遮水 / 耐薬品性 / 長期耐久性

Outline of Final Research Achievements

(1) The durability (chemical resistance and long-term durability) of FRC swelling gel is verified for aqueous solutions of neutral, acidic, and alkaline chemicals in the ground and artificial seawater. (2) The degree of deterioration of FRC powder can be adjusted by changing the high temperature condition (temperature: T0 = 200°C and time: t0) and “pre-deteriorated FRC powder” can be prepared. (3) Based on the results of swelling and permeability tests on pre-deteriorated FRC powder, the swelling ratio decreases due to thermal deterioration, but the maximum swelling pressure does not change. Even when thermal deterioration is extremely accelerated, the swelling ability is not lost and sufficient impermeable ability is maintained. (4) The durability time of fluidity was quantitatively evaluated for the maximum swelling ratio, 30 g/g, in the ground by using the newly proposed method and the Larson-Miller method. For example, the durability time of 33% deterioration is about 193 years.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

汚染物質を含む災害廃棄物は急激に増加しており，海面処分場などへの埋立て処分が検討されている．吸水性高分子ゲル（FRC）の劣化特性と耐久性（耐薬品性，長期耐久性）の評価手法を確立し，劣化の程度に対する耐久時間の定量評価を行った．埋立て処分における，汚染物質の安定的な遮断・漏出防止，跡地の高度利用のための基礎杭打設方法の実用化へと発展可能である．また，高分子材料の新たな材料開発や他分野における用途拡大および高度利用も期待される．さらに，吸水膨潤ゲルに対する試験法・評価法の確立は革新的な技術であり，建設材料としての発展のみならず，他の工学・医学分野などへの利活用が推進される可能性がある．