Verification of the cause of the peeling of the cover concrete and conversion to the inspection design by rainwater infiltration to reduce the maintenance cost

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02213
• 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 Institute of Technology
• Principal Investigator: Yoshida Ryo 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (40548575)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 中性化 / かぶり / 腐食 / 雨がかり / 実構造物 / 水分移動 / 混和材 / 空隙構造

Outline of Final Research Achievements

In this study, in order to drastically reduce the cost for maintenance, it was investigated that the actual structure to be repaired for the verification of reinforcing bar corrosion in the concrete standard specification, and carbonation and rainwater intrusion against peeling covered concrete. This verification showed the engineering basis for treating carbonation and rainwater intrusion equally as factors in the verification of rebar corrosion.
In addition, in order to prepare a new inspection method, basic data such as the relationship between rainfall pattern and rainwater intrusion property was acquired using the core collected from the cover of the actual structure, and the mechanism of rainwater intrusion in the cover was obtained. It was proposed that a constitutive rule based on the pore structure.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

コンクリート工学の開設以来、疑われなかった中性化寿命（仮）説について、設計供用年数を超えた実構造物の調査により検証した。この検証は、当時の設計思想に科学的根拠を与えるものであり、経験工学で体系化されたコンクリート工学を科学として深化させることに貢献した。また、鉄筋腐食の照査において中性化と雨水侵入を同等に扱うことは、点検や詳細調査による維持管理コストを下げるという社会的要求に応えるものである。