中文摘要：

通过人工气候模拟潮差区氯离子环境下混凝土的暴露试验，测定了不同暴露时间后的混凝土自由氯离子浓度，分析了其扩散系数及其时变性；以MIP法测定了不同暴露时间下混凝土的总孔隙率和孔径分布等孔隙特征参数，分析了其时变性；研究了潮差环境下混凝土扩散系数与孔隙微观参数的时变性关系，混凝土孔表面分形维数与扩散系数的关系。结果表明：在模拟潮差环境下，随着暴露时间的延长，混凝土氯离子扩散系数和总孔隙率均逐渐减小，而孔表面分形维数逐渐增大；不同暴露时间后，混凝土氯离子扩散系数与其各级孔隙率有较好的相关关系；混凝土不同孔径范围的孔表面分形维数与其氯离子扩散系数之间的相关性不同，其中以孔径范围为100～1000nm的大毛细孔的孔表面分形维数相关性最高。

英文摘要：

Through the artificial climate simulation exposure test of chlorion in concrete under the tidal range envi- ronment, the free chlorion concentrations in concrete after different exposure time were measured, the diffusion co- efficients and time-variability were analyzed. The gross porosities and pore diameter distribution in concrete after different exposure time were measured using MIP, and the time-variability was also analyzed. The time-variability relationship between the diffusion coefficients and the microscopic parameters of the pore in concrete under the tidal en,~ironment was studied, the relationship between the pore surface fractal dimension and the diffusion coefficients in test concrete was also analyzed. The results show that the chlorion diffusion coefficients and gross porosities in con- crete are all decreased gradually, and the pore surface fractal dimension in concrete increases gradually with the ex- tension of exposure time under the simulated tidal environment. The chlorion diffusion coefficients in concrete has better correlation with the all levels porosities in the concrete after different exposure time ; and there is different correlation between the pore surface fractal dimension of different pore diameter range and chloride diffusion coefficients in concrete, in which there is the best correlation between the pore surface fractal dimension of capillary porosity of 10 - 100 nm diameters and the chloride diffusion coefficients in concrete.