Study on Effect of Soaking Time on the Transmission of Chloride Ion in Concrete under Drying-Wetting Cycles
Acceleration penetration tests of chloride ion were conducted for typical diurnal and semidiurnal tidal types in China with consideration of various values of soaking time. It was found that the content of chloride ion from shallow area near the surface of concrete to the pure diffusion area of concrete reduced more significantly with the depth than that in the pure diffusion area of concrete. Based on Fick’s second law, the variation laws of chloride ion content at the edge of the pure diffusion area and chloride ion diffusion coefficient in the pure diffusion area under different soaking time ratios were identified by using the chloride ion content distributions that were established based on the test results of concrete in the pure diffusion area. It was found that the chloride ion content and the apparent chloride ion diffusion coefficient in pure diffusion area may be very high when the ratio of soaking time ratio is between 0.3 and 0.42 or 0.6 and 0.7 for diurnal tidal type and 0.83 for semidiurnal tidal type, which will cause severe erosion in concrete structures in tidal zone.
Q. Z. Zhang et al., "Study on Effect of Soaking Time on the Transmission of Chloride Ion in Concrete under Drying-Wetting Cycles", Advanced Materials Research, Vols. 261-263, pp. 61-68, 2011