| Project/Area Number |
06650641
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Building structures/materials
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| Research Institution | HOKKAIDO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
HOSHINO Masayuki Hokkaido Inst.of Tech., Faculty of Eng., Professor, 工学部, 教授 (70048049)
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| Co-Investigator(Kenkyū-buntansha) |
ITOU Toshiyuki Hokkaido Inst.of Tech., Faculty of Eng., Assistant, 工学部, 助手 (20223167)
TOMABECHI Tukasa Hokkaido Inst.of Tech., Faculty of Eng., Professor, 工学部, 教授 (40102785)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Aggregate / Bleeding Rate / Retaining Bleeding Rate / Boundary Surface / Structural Defect / Paste / Bond Strength / 構造的欠陥 / 付着機構 / ブリージング水 / 内部ブリージング率 / 強度判定法 / 実積率 / 砕石 / 表面粗さ |
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| Research Abstract |
Nowadays concrete is usually considered to belong to a category of composite material. However, it has been considered for many years that many structural defects are formed in concrete before hardening. Authors compared in this paper, the structural defects in the upper paste of coarse aggregate with those in the lower paste. There is a sufficient possibility that these structural defects are not uniformly dispersed in the paste. First of all, it is considered that the W/C ratio of the paste near the aggregate is not equal to that of the other paste in concrete before hardening.
For this reason, authors measured the W/C ratio with a color difference meter and the total pore volume with a porosimeter in respective boundary paste near the aggregate.
As a result,
1. It could be statistically confirmed with a risk percentage of 5% that the average value of color differece in hardened paste is larger near the lower boundary of the aggregate than near the upper boundary of the aggregate. This means that in concrete before hardening a larger quantity of seepage water remains near the lower surface of coarse aggregate.
2. The total pore volume of the hardened paste near the lower surface of coarse aggregate was confirmed to be larger than that near the upper surface of coarse aggregate.
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