盐雾环境下氯离子在混凝土中的扩散

通过模拟滨海盐雾环境,采用不同配合比的混凝土试样,进行盐雾环境下的腐蚀试验,研究盐雾氯离子在混凝土中的扩散模型.研究发现,盐雾氯离子在混凝土中的扩散与Fick第二定律的解析解存在一定差距.实验引入环境系数概念,提出经修正的Fick第二定律,推导出修正后的解析解.实验结果显示,实测数据和修正的Fick第二定律符合很好.在实际滨海环境下,选取两处有代表性的钢筋混凝土结构,在典型部位抽取芯样,考察了实际盐雾氯离子对混凝土结构的作用,结合当地环境特征,通过拟合数据点,确定环境系数,验证了环境系数在实际混凝土结构中的应用及其评价意义.

Diffusion of chloride ions into concrete in salt spray environment

A diffusion model of chloride ions in concrete with different materials mixtures was discussed by experiment and improved Ficks second law. The concrete samples were tested in a salt-fog box in which was controlled automatically, simulating the seashore salt-fog environments. The diffusion of chloride ions is different from the result calculated by the Ficks second law. Therefore, the Ficks second law was modified by introduced an environmental factor to make the calculated result conforming to the experimental data. The diffusion of chloride ions in reinforced concrete structure under real atmospheric environment was studied by drilling cylinder cores in some typical positions. The environmental factors in the practical concrete structures were ascertained according to the service environment of concrete structures. The application and significance of the environmental factor in real concrete structures were reviewed.