存在浓度峰的氯离子分布曲线及其扩散参数的计算方法

干湿交替下氯离子分布曲线中可能存在氯离子浓度峰。本文主要研究了不同水灰比对氯离子浓度峰的影响，以及适合这种氯离子分布曲线计算扩散参数的方法。实验结果显示，峰值氯离子浓度( Cmax )随水灰比呈双曲线关系增大，而浓度峰出现的位置与水灰比呈较好线性增长关系。此外，去掉氯离子增大阶段并以浓度峰出现的深度为零点拟合氯离子下降阶段的方法较为适合被应用于出现浓度峰的氯离子分布曲线中来获得扩散参数。

Chloride Profile with a Chloride Concentration Peak and Calculating Methods of Its Diffusion Parameters

A chloride concentration peak is prone to occur in the chlorideprofiles of concrete subjected to dying-wetting cycles. This research mainly investigated the influence of different water cement ratios ( W/C) on the occurring of chloride concentration peak. Besides, the appropriate calculating method of diffusion parameters was proposed for such chloride profiles with a concentration peak. The experimental results indicate that the peak value of chloride content (Cmax) presents a hysteric relation with increasing W/C, while the position where Cmax appears increased linearly with increasing W/C. Furthermore, the method of excluding the chloride content increasing part and starting from the position where Cmax appears to fit the chloride content phase is the proper way to obtain diffusion parameters of chloride profiles with a concentration peak. In addition, the method, excluding the increased content of chloride ions before the peak value and setting the exposure distance respective to the peak value as the zero point, was applied to obtain diffusion coefficient of chloride profile.