Estimation of Long-term Durability for Underground Concrete Structures

2011 Fiscal Year Final Research Report

• Project/Area Number: 21560491
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Civil engineering materials/Construction/Construction management
• Research Institution: Waseda University
• Principal Investigator: SEKI Hiroshi 早稲田大学, 理工学術院, 教授 (40120919)
• Research Collaborator: 杉橋 直行 清水建設(株), 実験データの検討 ; 山本 悟 日本防触工業(株), 腐食のメカニズム検討
• Project Period (FY): 2009 – 2011
• Keywords: 長期耐久性 / 還元性腐食 / 鉄筋腐食 / 不動態

Research Abstract

Corrosion phenomenon of underground concrete structures are examined. Surrounding conditions of structures are in the initial stage exposed to air condition(oxidation environment) and are in the long final stage surrounded with no air condition(deoxidized environment). Research work aims at the corrosion of reinforcing bar embedded in the concrete members. Following results are obtained from the electro-chemical experimental work.
(1) Corrosion rate of bars in the oxidation environment(app.20℃of water) is 0.0014～0.0095(μA/cm^2), and those in the deoxidized environment is 0.015～0.055(μA/cm^2), respectively.
(2) Though the polarization method of bar is effective technique so as to obtain corrosion rate, it is necessary to set the adequate measuring time and the adequate sweep speed of electric potential.
(3) The method of passivation electric current is the most suitable one so as to evaluate corrosion rate of bars under deoxidized environment

Research Products

• [Journal Article] 酸化性環境から還元性環境に至るコンクリート中鋼材の分極特性に関する研究 (2011)
  • Author(s): 金子聡志、朝瀬康平、関博、石川光男
  • Journal Title: コンクリート工学年次論文集 Volume: Vol.33, No.1
  • Peer Reviewed
• [Presentation] 酸化性環境から還元性環境への遷移期間におけるコンクリート中鋼材の腐食機構 (2011)
  • Author(s): 朝瀬康平、金子聡志、関博、石川光男
  • Organizer: 第37回土木学会関東支部技術研究発表会
  • Year and Date: 20110000
• [Presentation] 酸化性環境から還元性環境に至るコンクリート中鋼材の腐食機構に関する実験的検討 (2010)
  • Author(s): 金子聡志、朝瀬康平、関博、石川光男、杉橋直行
  • Organizer: 土木学会第61回年次学術講演会
  • Year and Date: 20100000
• [Book] 土木材料学 (2011)
  • Author(s): 町田篤彦, 関博, 薄木征三, 増田陳紀, 姫野賢治, 渡辺邦夫
  • Total Pages: 214
  • Publisher: オーム社