干湿循环下混凝土氯离子传输模型研究

Study on chloride transport model in concrete under drying-wetting cycles

在混凝土结构耐久性设计中,水位变动区通常被认为是最为关键的区域。首先从干湿循环下氯离子传输机理出发,考虑环境温度影响以及干燥过程和湿润过程水分传输差异,推导出了干湿循环状态下氯离子传输模型。其次设计出模型的有限体积算法,编制Matlab程序进行求解,利用该程序分别对暴露在海洋环境潮汐区3年混凝土结构中氯离子浓度分布进行了模拟计算,并与文献中的试验数据进行了对比,结果表明:所提出的干湿循环状态下的氯离子传输模型可以较好地模拟出潮汐区混凝土中的氯离子传输,由于考虑了全年环境温度周期变化以及干燥过程和湿润过程水分传输的差异,研究模型得到的计算结果较忽略这两方面影响得到的结果与文献中的试验数据更加吻合。

In the durability design of the concrete structures,tide zone was usually considered to be the most crucial area.Based on the chloride transportation mechanism in the drying-wetting cycle, considered the effects of temperature change and the moisture transmission differences in the drying-wetting process, and then built a chloride transportation model of the drying-wetting cycle.Then, designed a finite volume method of this model and compiled a Matlab program to solve the equation.Analog computations were conducted with this program to calculate the chloride distributions of concrete structures after 3-years exposing to the tidal zone in the marine environment, which were then compared with the experimental data in the literature.The results showed that the chloride transportation model proposed by this research can simulate the chloride trans- portation in the tidal zone well.