Buinding of chloride penetration model considering moisture transfer in RC structures and proposals to design and management.

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K13813
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22010:Civil engineering material, execution and construction management-related
• Research Institution: Kagoshima University
• Principal Investigator: Koike Kentaro 鹿児島大学, 理工学域工学系, 助教 (30781992)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 水分移動 / 塩分浸透 / 拡散 / 移流 / 水掛かり部 / マクロセル

Outline of Final Research Achievements

In this study investigated chloride ion penetration and rebar corrosion effect by cappilary water movement in concrete to purpose for buinding of chloride penetration model considering moisture transfer in RC structures and proposals to design and management.
In experiment of clarification of water movement in concrete with local water supply, there was humidity differece about 20% in narrow area aroud 3 to 5cm from local water supply point was confirmed as two-dimensional water movement by a humidity sensor embedded in the specimen. In addition, from result of experiment on same conditionby using rebar embedded concrete specimen, self-potential of rebar declined clearly aroud local water supply point was confirmed. That is, macro-cell corrosion was formed due to drstic humidity difference by local water supply was suggested.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

コンクリートにとって「水」は、セメントの水和反応や養生などのより良いコンクリートを作るうえで重要な要因である一方で、塩分浸透や鋼材腐食などの劣化現象においてもまた重要な役割を担っている。橋梁の劣化においても、橋面の排水不良に起因した桁受部や張出床版などの水掛かり部に、剥離、鉄筋露出などの変状が多数報告されており、「水」の影響を軽視できない状況にある。本成果は、コンクリートの水掛かり部における鋼材腐食のリスクやその影響範囲を評価し、橋梁をはじめとする各種構造物の水掛かり部の適切な点検・維持管理手法の提案に繋がる貴重な情報を示すことができた。