Effects of Loads and Erosion Dimensions on the Chloridion Transmission Rule in Concrete

To study the effects of load and erosion dimension on the characteristics of chloride ion erosion in concrete and its analysis method, dry-wet cycle experiments of chloride salt solution were carried out on components under continuous loads for a long time, including axially compressed, eccentrically compressed, and stress-free components, in both one-dimensional and two-dimensional manners. The distribution of free chloride ion content under different load properties and erosion dimensions was analyzed. The results showed that under a stress-free condition, the two-dimensional chloride ion erosion concentration at the same erosion depth was higher than that of one-dimensional erosion; axial compressive load had an inhibitory effect on the transmission of chloride ions, within the 0-40 mm depth range of the concrete surface, the two-dimensional chloride ion erosion concentration was greater than that at the same depth of one-dimensional erosion, but less than the one-dimensional erosion concentration under a stress-free condition; eccentric tensile stress accelerated the transmission of chloride ions, during both one-dimensional and two-dimensional erosion, the degree of chloride ion erosion in the eccentric tension zone was more severe than in the eccentric compression zone; in terms of erosion degree, the area above the horizontal plane of the erosion face > inclined plane > bottom face downwards. The influence of load effects on the diffusive properties of chloride ions was characterized by the “equivalent apparent chloride ion diffusion coefficient”, and its applicability had been verified through experiments. Based on the experimental research and theoretical analysis, a dimension influence function was introduced to modify the Fick diffusion model. The modified model’s calculated results were in good agreement with the measured two-dimensional chloride ion erosion results, indicating that it was feasible to describe the characteristics of two-dimensional chloride ion erosion using the modified model.