2004 Fiscal Year Final Research Report Summary
Study on Cracking behavior caused by pressure of corrosion products
| Project/Area Number |
15560406
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | KAGAWA University |
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Principal Investigator |
MATSUSHIMA Manabu KAGAWA University, Department of Engineering, Professor, 工学部, 教授 (00130302)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOTA Masaru SHIKOKU Research Institute INC, Civil Engineering Department, Chief Researcher, 土木技術部, 主席研究員
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| Project Period (FY) |
2003 – 2004
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| Keywords | Dry-wet repeated test / Cracking mode / Peeling off / horizontal peeling off / cracking along bar / cover depth / distance between bars |
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| Research Abstract |
In this paper, the prediction model of service period considered by the peeling off of concrete is developed due to cracking model of existing concrete structure received chloride ion damage. The deterioration of concrete structure consists of three stages, incubation period, progressive period and accelerative period. The service period is the term of the cracking propagation and differs by cracking mode induced by the corrosion pressure. The cracking mode depends on bar diameter, distance between bars, cover depth and concrete strength.
Dry-wet repeated test is carried out to investigate the cracking mode. Two type specimens are provided. One is the specimen to seek the border between the peeling off and the cracking along bar and the parameter of specimens is cover depth. Another is the specimen to seek the border between the horizontal peeling off and the cracking along bars and the parameter of specimen is the distance between bars. According to the results, the border between peeling off and cracking along the bars is obtained as D/φ=2.0〜3.0. Where, D=2t+φ, t is the cover depth, φ is diameter of bar. The peeling off is occurred under the value of D/φ mentioned above. The border between the horizontal peeling off and cracking along the bars is obtained as I/φ =5.5〜7.0. Where, I is the distance between bars.
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