Study on mechanism of local damage formation of concrete subjected to seawater attack

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06456
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Civil engineering materials/Construction/Construction management
• Research Institution: National Institute of Maritime, Port and Aviation Technology
• Principal Investigator: Yamaji Toru 国立研究開発法人海上・港湾・航空技術研究所, 港湾空港技術研究所, 領域長 (10371767)
• Research Collaborator: Kawabata Yuichiro ; Ogawa Shoichi ; Yoshida Natsuki
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: コンクリート / 海水 / 劣化 / ひび割れ / 耐久性

Outline of Final Research Achievements

This study investigated the mechanism of damage of concrete due to seawater attack. Also, the prediction method as well as accelerated testing method were investigated. As the result, the cause of seawater deterioration may be repetition of dissolution and precipitation of ettringite accompanying change of temperature and concentration of pore water. For prediction, simplified model for S penetration depth and Mg penetration depth was developed. Finally, wetting and drying test using seawater for cement paste with small diameter was proposed for accelerated test.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

本研究はこれまで着目されていなかったコンクリートの海水劣化に着目し，そのメカニズムを明らかにした点で学術的意義が高いと考える。また，海水劣化の予測法を提案したことで劣化予測が可能になり，また促進試験の活用により各種材料の海水劣化抵抗性を評価することが可能になり，コンクリート構造物の長寿命化等に貢献できる点は社会的にも意義が大きい。