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Title |
Crack and Time Effect on Chloride Diffusion Coefficient in Nuclear Power Plant Concrete with 1 Year Curing Period
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Authors |
천주현(Ju-Hyun Chun) ; 류화성(Hwa-Sung Ryu) ; 윤용식(Yong-Sik Yoon) ; 권성준(Seung-Jun Kwon) |
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DOI |
https://doi.org/10.11112/jksmi.2017.21.6.083 |
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Keywords |
원전콘크리트 ; 균열 폭 ; 정상상태 ; 확산계수 ; 재령효과 ; 겉보기 확산계수 Nuclear power plant concrete ; Crack width ; Steady-state condition ; Diffusion coefficient ; Age effect ; Apparent diffusion coefficient |
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Abstract |
Concrete structure for nuclear power plant is mass concrete structure with large wall depth and easily permits cracking in early age due to hydration heat and drying shrinkage. It always needs cooling water so that usually located near to sea shore. The crack on concrete surface permits rapid chloride intrusion and also causes more rapid corrosion in the steel. In the study, the effect of age and crack width on chloride diffusion is evaluated for the concrete for nuclear power plant with 6000 psi strength. For the work, various crack widths with 0.0~1.4 mm are induced and accelerated diffusion test is performed for concrete with 56 days, 180days, and 365 days. With increasing crack width over 1.0mm, diffusion coefficient is enlarged to 2.7~3.1 times and significant reduction of diffusion is evaluated due to age effect. Furthermore, apparent diffusion coefficient and surface chloride content are evaluated for the concrete with various crack width exposed to atmospheric zone with salt spraying at the age of 180 days. The results are also analyzed with those from accelerated diffusion test.
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