1993 Fiscal Year Final Research Report Summary
Evaluation of Fatigue of FRP Tendons based on Fracture Energy Theory
| Project/Area Number |
04452221
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
コンクリート工学・土木材料・施工
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| Research Institution | University of Tokyo |
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Principal Investigator |
UOMOTO Taketo University of Tokyo, Institute of Industrial Science, Professor, 生産技術研究所, 教授 (80114396)
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| Co-Investigator(Kenkyū-buntansha) |
OHGA Hiroyuki University of Tokyo, Institute of Industrial Science, Assistant Professor, 生産技術研究所, 講師 (40152061)
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| Project Period (FY) |
1992 – 1993
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| Keywords | FRP tendon / carbon fiber / aramid fiber / glass fiber / fracture energy theory / fatigue / creep / alkali resistivity |
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| Research Abstract |
Strength, deformation, and alkali resistivity of FRP tendons using carbon, aramid or glass fibers are studied. Based on fracture energy theory, fatigue properties of the FRP tendons are also evaluated considering the effect of mean stress as well as stress amplitude.
Main results in this study are as follows.
1. Strength of FRP tendons increases with an increase in fiber content. In the case of FRP tendons with high carbon fiber content, the strength are independent of fiber content in some stress area. This is attributed to the effect of stress intensity in the gripping chucks.
2. Fatigue strength is smaller for FRP tendons reinforced by glass fibers, and larger for carbon fibers. Tensile strength of FRP tendons using glass fibers after 4000000 cycles is about a half of virgin tensile strength.
3. As FRP tendons using aramid or glass fibers are suffered from creep, fracture of the FRP tendons due to both fatigue and creep is observed under the high stress condition.
4. The alkali resistivity of fibers can be evaluated by the tensile test results of fibers immersed in alkali solutions. Glass fibers are deteriorated remarkably by alkali solution, but there is almost no effect of alkalinity in the case of carbon and aramid fibers.
5. Deterioration of fibers due to alkalinity can be accelerated by the immersion test in high alkali concentration and high temperature solution. Also it can be predicted using the diffusion theory, and compared with deterioration under an actual environmental condition.
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