混凝土表面氯离子浓度时变规律试验研究

采用氯盐浸泡试验，定期检测了混凝土表面处的氯离子浓度，并对数据进行了拟合分析，研究了混凝土表面氯离子浓度随时间的变化规律，分析了氯盐溶液浓度、水灰比和粉煤灰掺量对表面氯离子浓度大小及其累积速率的影响。结果表明，表面氯离子浓度随时间的增加逐渐增长并最终达到稳定状态。随着氯盐溶液浓度的增加，表面氯离子浓度将更快地达到稳定状态，表面氯离子浓度也相应增大；水灰比越大，表面氯离子浓度累积速率越快，表面氯离子浓度越大；掺入粉煤灰可加快表面氯离子浓度的累积速率，表面氯离子浓度随粉煤灰掺量的增加而增大。通过对现有模型的比较与修正，提出了一个更为完善的模型。

Experimental Analysis on Time-dependent Law of Surface Chloride on Concentration of Concrete

Immersion in sodium chloride solution was adopted to periodically test chloride ion concentration at the surface of concrete and regression analysis was completed. And time-dependent law of surface chloride ion concentration of concrete with time was investigated. Influences of sodium chloride solution concentration, water to cement ratio and fly ash content on size and accumulation rate of surface chloride ion concentration were also analyzed. It is found that surface chloride ion concentration gradually grows with the of time increase the of time and reaches a steady state finally. With the increase of sodium chloride solution concentration, surface chloride ion concentration reaches the steady state more quickly and then increases numerically. Bigger water to cement ratio means quicker accumulation of surface chloride ion concentration and greater surface chloride ion concentration. Fly ash replacement could fasten accumulation of surface chloride ion concentration and surface chloride ion concentration increases with the increase of fly ash content. An improved model was proposed by comparison and correction of current models.