| Project/Area Number |
17K06515
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Civil engineering materials/Construction/Construction management
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
OHNO Kentaro 首都大学東京, 都市環境科学研究科, 助教 (80571918)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | コンクリート / 応力推定 / 超音波速度変化率 / 作用応力比 / 粗骨材 / モルタル / 相互相関 / 載荷方向 / 載荷軸直角方向 / 作用応力 / 超音波法 |
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| Outline of Final Research Achievements |
Introduced compressive stress in prestressed concrete members decreases with time, because concrete has some characteristics such as creep and dry shrinkage. Therefore, a demand for a stress estimation method in prestressed concrete member has emerged. Current stress estimation methods involve destructive action on a part of concrete.
In this study, stress estimation method in concrete by using ultrasonic wave method is investigated in a laboratory. In the experiment, column concrete specimens were prepared, then ultrasonic wave method were applied to these specimens under the compressive stress. The relation between the compressive stress change and the variation of ultrasonic velocity was investigated. As a result, linear relations of velocity variation and compressive stress ratio were clearly observed during loading state. The applied stress in concrete can be estimated by employing the variation of ultrasonic velocity propagated to the loading direction.
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| Academic Significance and Societal Importance of the Research Achievements |
プレストレストコンクリート（PC）構造は，PC鋼材の緊張によりコンクリートに圧縮応力を導入し，比較的大きなスパンの橋梁などに使用されている。ところが，様々な要因により導入プレストレスが減少するなど，供用中のPC橋の安全性が危惧されるところである。このような状況下において，PC部材の残留応力推定が重要であるが，現在実用化されている技術は，部材の一部破壊を伴うものであり，完全非破壊による応力推定手法の確立が望まれている。したがって，本研究で得られる成果は，非破壊でコンクリートの応力を推定する基礎的検討として重要な意義がある。
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