| Project/Area Number |
62550352
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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 |
コンクリート工学・土木材料・施工
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| Research Institution | Ritsumeikan University |
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Principal Investigator |
AMASAKI Shoji Ritsumeikan University, Civil Engineering, Professor, 理工学部, 教授 (60066743)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAGI Nobuaki Ritsumeikan University, Civil Engineering, Assistant, 理工学部, 助手 (50154753)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | ultrasonic spectrum analysis / ultrasonic pulse velocity / internal defect / concrete / nondestructive evaluation / compaction / wave energy / linear system / フレッシュコンクリ-ト / 締固め評価 / 早期劣化 / 非破壊評価 / 非破壊試験 / 応答関数のエネルギー / 音速 / コンクリート / 品質評価 / 応答関数 |
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| Research Abstract |
The following results can be drawn in this study.
(1) The system of ultrasonic spectrum analysis is not always linear and the response function is influenced by the property of transducer, the acoustically coupling method between transducer and concrete and the shape and the size of specimen. But this method is considered to be effective to evaluate the quality of concrete non-destructively.
(2) The higher frequencies of the transmitted ultrasonic pulse came to attenuate when the quality of concrete was poor or the specimens were deteriorated by ASR severely. In addition, the higher frequency came to attenuate with the increment of maximum size of coarse aggregate.
(3) Immediately after vibrating compaction,the wave energy through fresh concrete had increased by 10-20 dB than concrete compacted by the tamping rod. Pulse velocity of concrete compacted by vibrating was 100 -300 m/s for the distance of 10 cm. However, the time of propagation could not measured for the distance of 30 cm because the amplitude of pulse through fresh concrete was very small. This velocity is significantly larger than the theoretical estimate. It is easy to assess the degree of compaction for fresh concrete by the ultrasonic spectroscopy than the pulse velocity.
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