Study on maintenance method of existing PC road bridges subject to anti-freezing agent

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560566
• 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: Kobe University
• Principal Investigator: HIDENORI Morikawa 神戸大学, 工学(系)研究科(研究院), 教授 (70220043)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: プレストレストコンクリート / 道路橋 / 凍結防止材 / 腐食 / 応力腐食割れ / グラウト / 亜硝酸リチウム / 維持管理

Outline of Final Research Achievements

The insufficient grouting defects have been detected on existing PC bridges subject to anti-freezing agents. Owing to the chloride ion invading from anchorage element, the corrosion of PC wire with the insufficient grouting occurs with pitting. And PC wire with pitting corrosion is feared to occur the brittle fracture due to stress concentration. However, the deterioration mechanism has not been clarified and the repair method has not been developed. In this study, based on Stress Corrosion Cracking (SCC) tests and Hydrogen Embrittlement Cracking tests of PC wires with pitting, the mechanism of brittle fracture was clarified. Then, this study focused on a repair method that uses a lithium nitrite (LiNO2)-containing solution and grout. The repair performance of the method including anti-macro-cell corrosion was verified. Finally, the repair method was applied to an existing bridges and the monitoring measurements were conducted and the repair effects were evaluated.

Free Research Field

コンクリート工学