| Project/Area Number |
10650552
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
SENBU Osamu Hokkaido Univ., Grad. School of Eng., Assoc. Pro., 工学研究科, 助教授 (10236127)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1999: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Limestone / Coarse Aggregate / Concrete / Frost Deterioration / Thermal Coefficient / Stone Powder / 石灰石粗骨材 / 凍害 / 凍結融解試験 / 熱膨張係数 / 空気量 |
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| Research Abstract |
Although limestone is characterized by low water absorption and high specific gravity, it is said that frost durability of concrete with the limestone coarse aggregate is lower than concrete with the good coarse aggregates. In this paper, frost durability of concrete with the limestone aggregate is investigated. Results are shown as follows:
(1) According to the investigation of the past experiments, frost durability of concrete was not explained satisfactory by the basic property of coarse aggreegate.
(2) According to the test results of the basic property test of the limestone coarse aggregate, the limestone is characterized by low water absorption, high specific gravity, low thermal coefficient and high content of stone power.
(3) Differences of the thermal coefficient between the coarse aggregate and mortar cause thermal stress, and the low thermal coefficients of limestone cause large thermal stress. It is thought that the thermal stress affects frost deterioration of concrete.
(4) For concrete, an existence of stone powder has effects of reducing air content and improving frost durability.
(5) Freezing and thawing tests varied volume and the surface area of the coarse aggregate was conducted. It is thought that the effect of the thermal stress magnitude on frost durabllity of concrete is small. When the number of the coarse aggregate becomes large, frost durability of concrete becomes small. It is thought that number of cracks affect frost durability of concrete becomes small. It is thought that number of cracks affect frost durability of concrete.
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