2007 Fiscal Year Final Research Report Summary
Evaluation Methods of Mechanical Performance of RC members Application of Non-destructive Testing to Evaluation of Mechanical Performance of RC Beams with Corroded Reinforcing Bars by salt damage
Project/Area Number |
18360207
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Civil engineering materials/Construction/Construction management
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Research Institution | Osaka University |
Principal Investigator |
KAMADA Toshiro Osaka University, Graduate school of Engineering, Professor (10224651)
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Co-Investigator(Kenkyū-buntansha) |
MIYAZATO Shinichi Kanazawa Institute of Technology, Department of Civil & Environmental Engineering, Associate professor (60302949)
OONISHI Hiroshi Osaka University, Graduate school of Engineering, Assistant professor (70283728)
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Project Period (FY) |
2006 – 2007
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Keywords | Reinforced Concrete / Salt damage / Nondestructive test / FEM analysis / Ultimate Strength / Deterioration condition / Electro-Chemical Methods / Bonding |
Research Abstract |
Generally, concrete inspections are applied to determine the current strength and durability of a structure. However it is difficult to determine the strength and performance of a structure from inspection results, therefore currently indirect estimation from visual observation of cracks, corrosion levels from nondestructive test among others are used. Therefore, developing a method to directly determine the current conditions of a structure in a standardized manner will enhance rationalization of management of structures. In this study, first, various non-destructive tests (Ultrasonic Methods, Half Cell Potential Methods and Polarization Resistance Methods) were performed on reinforced concrete beams whose reinforcing bars have been corroded through electricity. The specimen was a rein-forced concrete beam of width 230 mm, height 230 mm and length 1500 mm with the tensile side having 3 reinforcing bar at a 75 mm span. The rebar cover was 33 mm from the sides and bottom of the specimen.
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Corrosion enhancement experiment was conducted to rebar. The specimen was placed on top of a metallic plate sat at the bottom of a stainless steel container full with 3% saline solution. A circuit was made with the metallic plate as the cathode and the rebar protruding from the specimen as the anode and 1Amp direct current fed into the circuit. Two periods of current flow, 14 days and 28 days were set in order to have specimens with varying levels of corrosion. Second, damage maps were made which reflect the results of nondestructive tests. The results were then input into finite element method (FEM) analysis and the mechanical performance of the test specimens investigated. Last, the adequacy of the FEM analysis results were confirmed by carrying out flexural loading tests on the rein-forced concrete beams whom reinforcing bar have been corroded. The following conclusions were obtained in this study. 1. It was possible to grasp the extent of deterioration in a corroded reinforced concrete beam from deterioration maps estimated by results of various nondestructive test methods. Furthermore, the use of FEM analysis as an effective method in evaluation of structures' mechanical performance was confirmed. 2. It was possible to use FEM analysis utilizing results from nondestructive test, to simulate on the whole the crack properties and load-displacement response of reinforced concrete beams with corroded rebar. However, FEM analysis was unable to simulate loading tests with peculiar failure modes. From the above, it is of the view that the importance to replicate cracks on the concrete surface caused by corrosion, in the analysis model has been made clear. Less
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[Journal Article] Application of Non-destructive Testing to Evaluation of Mechanical Performance of RC Beams with Corroded Reinforcing Bars2007
Author(s)
Hiroyuki, MINEZAWA, Toshiro, KAMADA, Shinichi, MIYAZATO, Ichira, KURODA, Hiroshi, ONISHI, Shinya, UCHIDA
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Journal Title
Proceedings of the Concrete Structure Scenarios Vol.8
Pages: 425-432
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Basic Study on Evalu ation of Mechanical Performance of RC Beams by FEM using the results of NDT2007
Author(s)
Hiroyuki, MINEZAWA, Toshiro, RAMADA, Shinichi, MIYAZATO, Ichiro, KURODA, Hiroshi, ONISHI, Shinya, UCHIDA
Organizer
The 62nd Annual conference of JSCE
Place of Presentation
Hiroshima University
Year and Date
2007-09-13
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Basic Study on Calcul ation for Mechanical Performance of RC Beams2007
Author(s)
Hiroyuki, MINEZAWA, Toshiro, KAMADA, Shinichi, MIYAZATO, Ichira, KURODA, Hiroshi, ONISHI, Shinya, UCHIDA
Organizer
Annual conference of JSCE KANSA] division 2007
Year and Date
2007-05-26
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Change of the wave vel ocity at the surface layer of RC member due to galvanic corrosion test of rebar2007
Author(s)
Hiroyuki, MINEZAWA, Toshiro, KAMADA, Shinichi, MIYAZATO, Ichiro, KURODA, Hiroshi, ONISHI, Shinya, UCHIDA
Organizer
JSNDI Spring Conference 2007
Place of Presentation
Arcadia Ichigaya
Year and Date
2007-05-22
Description
「研究成果報告書概要(欧文)」より