| Project/Area Number |
11650578
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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 | Tokyo Institute of Technology |
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Principal Investigator |
TANAKA Kyoji Tokyo Institute of Technology, Materials and Structure Laboratory, Professor, 応用セラミックス研究所, 教授 (40016829)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Repeated load / Fatigue / Concrete / Mortar / Pore structure / Carbonation / Curing condition / Degree of fatigue / 疲労試験 / 繰返し載荷 / アコースティク エミッション / 疲労曲線 / 養生条件 / 応力 / 細孔 |
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| Research Abstract |
(1) Fatigue tests of concrete and mortar specimens were carried out at various levels of stresses. The rise of the stress level was found out to accelerate fatigue rupture of them. The further fatigue tests that the stress levels are lower than the ones of fatigue rupture were conducted, and the scale on the Gompertz curve was proposed for expressing the degree of fatigue of specimens.
(2) As for the effect of curing conditions in early ages, such as water immersed cures of 1, 28, 90days and sealed cure of 7 days, it was made clear that insufficient cure is susceptible to decrease of fatigue resistance.
(3) Acoustic emission observation made clear that the existence of the three stages to fatigue rupture such as the initiation stage of fatigue, the gradually accumulated stage of fatigue and the last stage of rapidly progressing fatigue.
(4) Pore structures of the specimens fatigued were investigated by the mercury-intrusion technique, it was found out that the pore volumes of them increased according with the progress of fatigue.
(5) Carbonation rate that is an index of durability was also accelerated for the specimens of poorly cured according with progress of fatigue. It is considered due to the increase of pore volume of capillary size.
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