| Project/Area Number |
11650593
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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 |
Building structures/materials
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| Research Institution | Hachinohe Institute of Technology |
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Principal Investigator |
TSUKINAGA Yoichi Hachinohe Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (60124898)
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| Co-Investigator(Kenkyū-buntansha) |
ABA Mirotu Hachinohe Insitute of Technology, Faculty of Engineering, Assistant Professor, 工学部, 講師 (10295959)
SHOYA Masami Hachinohe Institute of Technology, Faculty of Engineeiing, Professor, 工学部, 教授 (80006684)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Concrete / Freezing and thawing action / Deicer salt / Scaling / Moisture content / Thermal shock / Pull-off test / Air-void character / 微小硬度 / プルオフ法 / 透過性 |
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| Research Abstract |
(1) Mechanism of frost damage
The mechanism of frost damage of concrete was investigated from the reference. The mechanism of the scaling was put in order by 6 types. It thought that these mechanisms were compound actually, and that some of the mechanisms excelled in some case and that the scaling developed.
(2) Actual state of frost damage at the concrete structures
The actual state of frost damage of concrete at the Tohoku district was investigated by the questionnaire. Deterioration symptom, area, members, time, causes, and repair of the frost damage, and the spreading amount of deicer salts were considered.
(3) Effect of quality of surface layer of concrete on scaling resistance
It supposed that the thermal shock which occurs in case of the chloride operation influenced a scaling. Scaling resistance can be increased in securing to fixed value in the pore structure and the strength of the concrete surface. However, the fact that the influence of the water content is larger than the pore structure and the strength was confirmed.
(4) Scaling resistance of concrete containing various coarse aggregates
The scaling resistance of the concrete containing low-quality aggregates or fly ash artificial aggregates was improved when securing fixed water cement ratio and air content. However, scaling damage of concrete could not be estimated solely from the density and the moisture content of aggregates.
(5) Scaling resistance of steam-cured concrete
When mixing required air content in steam-cured concrete, the scaling amount decreased and even if various manufacturing conditions were changed, differences with remarkable scaling amount were not confirmed. Therefore, it supposed that to mix required air content was very important to secure the scaling resistance of steam-cured concrete.
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