Nondestructive evaluation of corrosion of steel members penetrating concrete floor system

Research Project

Project/Area Number	24560587
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Structural engineering/Earthquake engineering/Maintenance management engineering
Research Institution	Tokyo City University
Principal Investigator	SHIRAHATA Hiromi 東京都市大学, 工学部, 准教授 (40298013)
Co-Investigator(Renkei-kenkyūsha)	KISHI Toshiharu 東京大学, 生産技術研究所, 教授 (90251339)
Project Period (FY)	2012-04-01 – 2015-03-31
Project Status	Completed (Fiscal Year 2014)
Budget Amount *help	¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000) Fiscal Year 2014: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000) Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords	橋梁 / 腐食 / 界面 / 鋼 / コンクリート / 非破壊検査 / 鋼・コンクリート界面 / 超音波探傷 / 赤外線サーモグラフィ / 超音波探傷試験
Outline of Final Research Achievements	Deterioration of civil infrastructure is getting one of the most serious problems, recently. A diagonal member of a steel truss bridge was cut off due to the corrosion in the 2000s. The truss member was embedded in the reinforced concrete floor systems. The structural detail was not appropriate in terms of water drain. This study aims at developing nondestructive technique that detects the corrosion. Among nondestructive methods, thermography and ultrasonic test were applied. Detachment and water puddle in the interface between concrete floor and steel diagonal member was detected by the thermography. Temperature rate of the interface decreased more slowly, when water exists in the interface. Ultrasonic test was also applied to detect the detachment and thickness reduction by the corrosion. Some ultrasonic techniques such as SV (vertical shear) wave, SH (horizontal shear) wave, and Rayleigh (surface) wave methods. SV wave showed good detection ability among those methods.