海洋环境下港口工程混凝土界面过渡区氯离子扩散系数模型

通过现场暴露物理试验,实测得到了港口工程混凝土及相对应的水泥砂浆试件中氯离子的浓度分布结果,经回归分析分别得到了这两种试件的氯离子扩散系数。以此为基础,定量评估了粗骨料的稀释、曲折和界面过渡区效应对混凝土中氯离子扩散系数的影响,并建立了混凝土界面过渡区氯离子扩散系数模型。基于混凝土中氯离子扩散的细观数值模拟方法,验证了所建立的混凝土界面过渡区氯离子扩散系数模型的正确性。对细观数值模拟结果的分析可知:界面过渡区对混凝土中仅考虑粗骨料的稀释和曲折效应的氯离子扩散系数的提升效应不可忽略,应充分考虑界面过渡区的存在对混凝土中氯离子浓度分布和扩散特性的影响。

Chloride diffusion coefficient model of interfacial transition zone of concrete with port engineering in marine environment

Chloride concentration profiles of concrete specimens with port engineering and their corresponding mortar specimens are measured and obtained during the in-site field exposed experiment,and the chloride diffusion coefficients of these two types specimens are determined by regression analysis.On the basis of the two chloride diffusion coefficients,the influences of dilution,tortuosity and interfacial transition zone effects on chloride diffusion coefficient of concrete are quantified,as well as the chloride diffusion coefficient model of interfacial transition zone of concrete is established.The accuracy of the aforementioned model is validated based on the meso-scopic numerical simulation method of chloride diffusion into concrete.Based on the analysis of the mesoscopic numerical simulation results,it can be seen that the enhancement effect of interface transition zone on chloride diffusion coefficient in concrete considering only the dilution and zigzag effects of coarse aggregate cannot be ignored.The influence of the interfacial transition zone on the chloride concentration distribution and diffusion characteristics in concrete should be considered.