Development of lightweight, high-performance zonotolite-based building materials

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04787
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 23010:Building structures and materials-related
• Research Institution: Muroran Institute of Technology
• Principal Investigator: HAMA Yukio 室蘭工業大学, 大学院工学研究科, 教授 (70238054)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ゾノトライト / オートクレーブ法 / 軽量気泡コンクリート / 細孔構造 / 乾燥収縮 / 炭酸化 / 耐熱性 / 撥水性

Outline of Final Research Achievements

The objective of this study was to establish the optimum synthesis conditions for the industrial hydrothermal synthesis of zonotolite using cement as a starting material, and to understand the basic properties of zonotolite-based lightweight hardened materials. As a result, it was clarified that the formation of zonotolite is a transition from low crystallinity C-S-H, tobamolite crystals, and zonotolite crystals, in that order, and the optimum hydrothermal synthesis conditions were found. The compressive strength, drying shrinkage, heat resistance, and carbonation shrinkage properties of the hardened compact were confirmed. Although the formation of zonotolites causes a shift in the pore size distribution toward the coarse size and an increase in shrinkage, it was found that silicone oil can provide water repellency and resistance to carbonation even under high temperature conditions of 230°C by using the chemical vapor deposition (CVD) method.

Free Research Field

建築構造・材料

Academic Significance and Societal Importance of the Research Achievements

本研究の学術的意義は，従来は不可能とされていたセメントを出発原料としたゾノトライトの工業的合成を，セメント中のアルミ成分の先行反応後にオートクレーブ養生を行う前水和方式により可能とし，そのメカニズムと最適条件を見出した点と耐熱温度が200℃程度のシリコーンオイルで230℃の高温処理を行うゾノトライトの製造時に化学気相成長法（CVD法）でシリコーンオイルによる撥水性の付与が可能で，炭酸化抵抗性の向上に寄与することを明らかにした点である。これにより，従来のALCよりも耐熱性が高く耐炭酸化性に優れた新しい建築材料を提供できるようになることは社会的にも意義が大きい。