Challenge of developing a geopolymer with low carbon dioxide emission and absorption properties

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22003
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 23:Architecture, building engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: IGARASHI Go 東京大学, 大学院工学系研究科(工学部), 特任講師 (10733107)
• Co-Investigator(Kenkyū-buntansha): 山田 一夫 国立研究開発法人国立環境研究所, 福島支部, 主任研究員 (30590658)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 低炭素建設材料 / M-S-H / 水酸化マグネシウム

Outline of Final Research Achievements

As budding research for the development of geopolymer production and curing processes focusing on the reduction of carbon dioxide emissions, we have mainly worked on the elucidation of the reaction mechanism and performance expression mechanism of geopolymers made from magnesium silicate and obtained material and physical properties that can be used for the development of high-performance geopolymers suitable for solidification treatment. We obtained the physical properties of the geopolymer. From the results of reactivity test of lightly burnt magnesium oxide, flow test of fresh paste, compression test, thermogravimetric analysis, and powder X-ray diffraction analysis, it was confirmed that the compressive strength and Young's modulus increased with the progress of material age regardless of the mixing ratio of lightly burnt magnesium oxide and silica fume. The increase in compressive strength and Young's modulus was attributed to the formation of magnesium hydroxide and M-S-H phase.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

現状のコンクリート工学（建築・建設材料学）分野において、セメントの使用量の削減は、建築・建設分野において二酸化炭素排出量の削減に大きく貢献できるため、産業副産物によるセメントの一部代替や、セメントフリーのジオポリマーの開発が取り組まれている。この現状を踏まえ、マグネシウムを原料とした硬化体は、ポルトランドセメントと比較して、二酸化炭素排出量の低減だけにとどまらず、二酸化炭素を吸収できる建築・建設材料の発明につながる可能性を見出せるという観点から今後のコンクリート工学（建築・建設材料学）分野における新たな材料開発・材料評価手法の飛躍的な発展に貢献できることが期待される。