Clarification of internal swelling reaction mechanism from the viewpoint of fracture mechanics and proposition of assessment methodology of structural performance

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01407
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22010:Civil engineering material, execution and construction management-related
• Research Institution: Nagoya University
• Principal Investigator: Miura Taito 名古屋大学, 工学研究科, 准教授 (10718688)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 内部膨張劣化 / 離散解析 / 破壊力学 / 付着性状

Outline of Final Research Achievements

In this study, the expansion behavior, changes in mechanical properties of concrete, changes in adhesion properties of reinforcing bars, and changes in structural performance at the RC member level inherent in the internal expansion reactions ASR (alkali-silica reaction) and DEF (delayed ettringite formation) of concrete were evaluated through experimental and analytical studies.
As a result, we proposed that the spatio-temporal distribution of the expansion phase has a significant influence on the macroscopic expansion behavior in the expansion anisotropy of ASR and DEF. A systematic mechanism of mechanical property degradation applicable to both mechanical and expansion cracks was proposed. Conducted an international joint research project between Japan and France to obtain the world's first experimental data on adhesion degradation of steel bars due to expansion and proposed a mechanism for this degradation.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

膨張に関する力学現象を評価可能な世界最先端の数値解析手法を開発し、破壊力学的観点から統一的・体系的に説明可能な膨張異方性メカニズムを提唱しており、次世代の膨張研究の潮流の中核となる研究成果を輩出した。
膨張異方性メカニズムに立脚したひび割れ情報に基づく破壊力学指標による膨張異方性と力学特性低下の推定手法により、膨張劣化した構造物の耐久性照査手法を刷新することができる可能性が非常に高く、学術的分野への貢献だけでなく、高い工学的価値を有している。