1996 Fiscal Year Final Research Report Summary
Study on the deterioration of structural performance of RC members due to rebar corrosion
| Project/Area Number |
06402045
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TOMOSAWA Fuminori The University of Tokyo, Dept. of Archtecture, Fac. of Eng., Professor, 大学院・工学系研究科, 教授 (50211404)
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| Co-Investigator(Kenkyū-buntansha) |
NOGUCHI Takafumi The Univ. of Tokyo, Dept. of Arch., Fac. of Eng., Research Associate, 大学院・工学系研究科, 助手 (80208321)
OTANI Syunsuke The Univ. of Tokyo, Dept. of Arch., Fac. of Eng., Professor, 大学院・工学系研究科, 教授 (30133101)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Corrosion of Rebar / Crack / Yield Point / Bond / Finite Element Analysis / Beam / Column / Carbon Fiber Sheet |
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| Research Abstract |
The study was made on the quantitative evaluation of the relationship between the level of rebar corrosion and the structural performance of RC members, and on the application of carbon fiber sheet to strengthening of RC members deteriorated due to rebar corrosion. The following results were obtained.
1. Finite element analysis showed that the direction of cracking differed according to the forms of corrosion and the localized corrosion needed more amount of rust to create cracking of cover concrete.
2. The mechanical properties of rebar subjected to pitting corrosion and uniform corrosion were expressed as a function of the weight loss percentages of rebar and introduced into the constitutive law of rebar in FEM analysis.
3. Pull-out tests were conducted on rebars corroded to different extent, and the bond strength and the bond stiffness were expressed as a function of the weight loss percentages of rebar.
4. Using the constitutive law of corroded rebar element and that of bond element, finite element analyzes were made on RC beams with corroded rebars. Comparing the results of the analyzes to the experimental results, the validity of the constitutive laws were examined.
5. Carbon fiber sheet was effective for the strengthening of both bending strength and shear strength of RC beams with corroded rebars. As the peeling of the sheet determines the strength of beams, sufficient bond area make both the strength and the performance of deformation of beams increase.
6. Confining effect disappeared in column above 30% of weight loss of hoop and the strength of column decreased, resulting from the bond failure due to the cracking of cover concrete, the spalling of cover concreate, the decrease of the confining effect due to the breaking of hoop and the decrease of the strength of rebar.
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