摘要
当前对于海洋环境下混凝土结构中氯离子的扩散问题的数值模拟研究大多停留在宏观层面,没有考虑混凝土细观结构的影响。针对这一问题,建立了混凝土三维球形随机骨料细观模型,并基于该模型提出了混凝土中氯离子扩散细观数值模拟方法。混凝土三维球形随机骨料模型以随机过程理论为依据,考虑了骨料粒径大小和位置分布的随机性,更接近实际情况;基于该模型的氯离子扩散细观数值模拟方法能够从细观层面反应混凝土中氯离子扩散规律,可以作为混凝土中氯离子扩散研究的重要手段。在此基础上研究了混凝土细观结构对氯离子扩散的影响,结果表明:界面过渡区厚度和扩散系数越大时,经扩散进入混凝土中的总体氯离子含量越多,但混凝土浅层区域内的氯离子含量越少;随着粗骨料体积分数的增加,混凝土中相同深度处的氯离子浓度降低。
In marine environment, the chloride diffuses in concrete structure, now most numerical simulations of which remain in macro level, ignoring the influence of concrete meso structure. Concerning this issue, the three- dimensional spherical random aggregate model was developed. Based on the model, the method of meso-scale nu- merical simulation for chloride diffusion in concrete was proposed. The three-dimensional spherical random aggre- gate model takes account of the randomness of aggregate diameter and position, according to random process theory. The method of meso-scale numerical simulation for chloride diffusion based on this model is able to reflect chloride diffusion law in meso-scale. It can be used as an important measure to study chloride diffusion in concrete. The ef- fects of meso structure on the process of chloride diffusion in concrete were studied using this method. The results indicate that as the thickness and diffusion coefficient of ITZ increase, the total chloride contents diffused into con- crete specimen increase accordingly, while the chloride concentration in the superficial zone decreases. With in- creasing of the volume fraction of coarse aggregate, the chloride concentration of the same depth decreases.
出处
《水道港口》
2017年第1期59-65,共7页
Journal of Waterway and Harbor
基金
交通运输部交通建设科技项目(2014328224040)
国家自然科学基金(51279128)
国家自然科学基金创新研究群体科学基金(51321065)
