|
Title |
The Comparison of Apparent Chloride Diffusion Coefficients in GGBFS Concrete Considering Sea Water Exposure Conditions
|
|
Authors |
윤용식(Yong-Sik Yoon) ; 정기찬(Gi-Chan Jeong) ; 권성준(Seung-Jun Kwon) |
|
DOI |
https://doi.org/10.11112/jksmi.2022.26.2.18 |
|
Keywords |
옥외 폭로 시험; 고로슬래그 미분말; 염해; 겉보기 염화물 확산계수 Outdoor exposure test; GGBFS; Chloride ingress; Apparent chloride diffusion coefficient |
|
Abstract |
In this study, the time-dependent chloride ingress behavior in GGBFS concrete was evaluated considering marine exposure conditions and the properties of concrete mixtures. The concrete mixture for this study had 3 levels of water to binder ratio and the substitution rate of GGBFS, and outdoor exposure tests were performed considering submerged area, tidal area, and splash area. According to the evaluation results of diffusion coefficient considering properties of concrete mixtures, as the substitution rate of GGBFS increased, the decreasing rate of the diffusion coefficient decreased based on exposure periods of 730 days(2 years). As the evaluation result of the diffusion behavior according to the marine exposure conditions, the diffusion coefficient was evaluated in the order of submerged area, tidal area, and splash area. In tidal area, a relatively high diffusion coefficient was evaluated due to the repetition of wet and dry seawater. In this study, the effects of GGBFS substitution rate on the decreasing behavior of apparent chloride diffusion coefficient was analyzed in consideration of exposure conditions and periods. Linear regression analysis was performed with apparent chloride diffusion coefficient as output value and GGBFS substitution rate as input value. After 730 days of exposure, the effect of GGBFS on diffusion coefficient was significantly reduced. Even for OPC concrete, after 730 days, the diffusion coefficient was as low as that of GGBFS concrete, so the gradient of the regression equation decreased significantly. It is thought that improved durability performance for chloride ingress can be secured before 730 days through the use of GGBFS.
|