双层钢筋混凝土的电化学脱盐研究

采用双层钢筋混凝土试件,研究水与水泥的质量比、氯离子含量和保护层厚度对硅酸盐水泥混凝土电化学脱盐的影响,通过测定混凝土不同深度处氯离子含量的变化,分析脱盐效率随时间的变化趋势;探讨电化学脱盐后混凝土力学性能和微观产物的变化。结果表明,混凝土各部位氯离子的脱除效率与混凝土的密实性、氯离子的浓度梯度和混凝土中的电场强度密切相关;混凝土的电化学脱盐效率随着水与水泥质量比的增加和保护层厚度的减小而提高;初始氯离子的含量对脱盐效率的影响应考虑氯离子的浓度梯度和通电量而定;电化学脱盐技术可降低混凝土中氯离子的含量,进而提高钢筋混凝土的耐久性。

Electrochemical Chloride Extraction of Concrete with Two Layers of Steel Rebars

The influences of mass ratio of water and cement,chloride content and cover thickness on the electrochemical chloride extraction(ECE) of Portland cement concrete were investigated,and the mechanical properties was discussed as well.The phase composition and morphology of hydration products of concrete desalting for different time was analyzed with X ray diffraction.The content of chloride in different depths and variation trend were analyzed.The results indicate that the efficiency of ECE is determined by the concrete density,chloride concentration gradient and electric field intensity.The electrochemical desalting efficiency increases with the increasing of mass ratio of water and cement,but the effect of the cover thickness is opposite.It is the concentration gradient and the electric flux that determinates the effect of desalting efficiency.The electrochemical desalting can be used as an effective method to improve the durability of reinforced concrete.