| Project/Area Number |
09450206
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
WATANABE Fumio Kyoto University, Faculty of Engineering, Professor, 工学研究科, 教授 (50026267)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIYAMA Minehiro Kyoto University, Faculty of Engineering, Associate Professor, 工学研究科, 助教授 (50183900)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | reinforced concrete / flexural compression / lateral confinement / constitutive law / stress / strain / コンクリート |
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| Research Abstract |
The objective of this research is idealization of stress-strain curve of high-strength confined concrete in members subjected to flexural compression.
In the year of 1997 experimental results of axial loading tests on high-strength confined concrete cylinders and prisms carried out in the past were reviewed. Based on the results analytical work was conducted as follows ;
(1) The ratio of the maximum confining lateral pressure evaluated by the amount and strength of confining reinforcement, and lateral confining pressure at the maximum strength was formulated as a function of the standard cylinder compression strength. The strain at the maximum strength was expressed by the ratio of the lateral confining pressure to the standard cylinder compression strength. A formula giving the stress and strain at the maximum strength of the confined concrete was derived as a function of lateral confining pressure at the maximum strength.
(2) A model for confined cross section which consists of concrete and steel discrete elements was developed. Numerical calculation using the model to obtain stress-strain curve was conducted.
(3) The above numerical calculation was applied to cross sections with various types of steel configuration.
(4) Maximum strength was predicted by lateral confining pressure. Idealization of a whole stress-strain curve of confined concrete was proposed.
In the year of 1998 bi-directional loading tests on reinforced concrete columns were conducted. The moment-curvature relationship in the plastic hinge region obtained by the tests was compared with the analytical results which were based on the stress-strain curve model from the standard cylinder compression tests. The difference between the experiment and analyses was, considered due to application of the stress-strain curve obtained by the axial loading tests to the concrete under flexural compression. A coefficient which is able to compensate the difference was proposed.
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