Study on the pore distribution and the frost damage resistance of concrete containing modified fly-ash

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06648
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Building structures/Materials
• Research Institution: Oita University
• Principal Investigator: Otani Toshihiro 大分大学, 理工学部, 教授 (00315318)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: フライアッシュ / コンクリート / 耐凍害性 / ポゾラン反応 / 空気量 / 細孔量 / 気泡間隔係数

Outline of Final Research Achievements

The purpose of this study is to clarify the influence of air loss on fresh stage and change of pore distribution by long term curing on the frost damage resistance of concrete containing modified fly ash (MFA), freeze-thaw test, compressive strength test, measurement of an air void spacing factor and a pore size distribution with specimen of each stage.
The test results showed that MFA concrete had same the freeze-thaw resistance to plane concrete, and a concrete of which air void spacing factor of under 300µm had high freeze-thaw resistance, regardless with or without of MFA. Furthermore, a densifying the pore structure by pozzolanic reaction of MFA at the age of 1year had no influence on freeze-thaw resistance, and a concrete of which compressive strength of over 35N/mm2 had high freeze-thaw resistance, regardless with or without of MFA.

Free Research Field

建築材料

Academic Significance and Societal Importance of the Research Achievements

現在、建設業界における環境負荷低減策として、構造物の長寿命化および産業副産物等の有効活用が求められ、石炭火力発電所で発生するフライアッシュの活用が期待されている。フライアッシュはポゾラン活性を有し、コンクリートの長期的な組織の緻密化や化学抵抗性などが向上する優れた材料であることは周知されているが、本研究の課題は十分に明らかにされていなかった。本研究の成果によって、フライアッシュのさらなる活用の促進が期待できる。