Seasonal Variation of Surface Chloride Ion Content and Chloride Diffusion Coefficient in a Concrete Dock

摘要

Concrete powder collected in-situ from a 5-year-old concrete dock in four seasons respectively was tested by rapid chloride test (RCT). Based on Fick's second law, the surface chloride ion content and the chloride diffusion coefficient are derived by regression analysis, and the seasonal variation laws of the two parameters are discussed. Both parameters vary with the season as single-peak laws. The surface chloride ion content reaches the peak value in summer, while the peak of the chloride diffusion coefficient occurs in spring. Possible reasons for these phenomena are discussed in this paper. Finally, the choice of inspection time for those two parameters in different engineering applications is advised and this may make contribution to more accuracy of chloride diffusion prediction in engineering applications.