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Title |
Prediction of Time to Corrosion for Concrete Bridge Decks Exposed to De-Icing Chemicals
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Keywords |
제빙화학제; 콘크리트 교량 바닥판; 내구수명 예측; 표면 염소이온량; 염소이온 확산계수; de-icing chemicals; concrete bridge deck; service life prediction; surface chloride concentration; chloride diffusion coefficient |
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Abstract |
The major cause of deterioration for the concrete bridge decks exposed to de-icing chemicals would be chloride-induced reinforcement corrosion. Thus, in this paper, in order to predict time to corrosion for concrete bridge decks in the urban area, chloride concentration was measured with depth from the surface. A frequency analysis on surface chloride concentration and chloride diffusion coefficient of concrete bridge deck equals 0.192, 29.828 in the scale parameter and 7.899, 1.983 in the shape parameter of gamma distribution. The average value of surface chloride concentration equals 1.5 kg/㎥ and condenses from 1 to 2 kg/㎥ in the level of probability 70%. From the probabilistic results, it is confirmed that 26mm of minimum cover depth in order to target 20 years over is calculated. The countermeasure strategy to extend the service life of concrete bridge deck exposed to de-icing chemicals would be an effective method to increase cover depth and to place high performance concrete, which could lead to reduce the chloride diffusion coefficient and distribution range.
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