非饱和混凝土氯离子传输模型及参数分析

发布时间：2018-04-17 21:35

  本文选题：非饱和混凝土 + 氯离子　； 参考：《硅酸盐通报》2017年04期

【摘要】：实体工程中大多数混凝土结构由于干湿交替作用处于非饱和状态,研究非饱和混凝土中的氯盐侵蚀对混凝土耐久性具有重要的意义。根据氯离子在混凝土中的传输机制,考虑干湿交替过程中水分传输的差异,推导得出氯离子在非饱和混凝土中传输的对流-扩散控制方程。采用精度高的Crank-Nicolson格式对水分扩散方程、氯离子对流-扩散方程进行差分,并用MATLAB软件编程进行数值求解。试验结果与模型计算结果吻合良好,通过参数敏感性分析结果可知,氯离子浓度随着混凝土表层孔隙饱和度和干湿比的增加而减小,当混凝土初始饱和度为0.3时氯离子浓度最高。
[Abstract]:Most concrete structures in solid engineering are in unsaturated state because of the alternating action of dry and wet. It is very important to study the chloride corrosion in unsaturated concrete for the durability of concrete.According to the transport mechanism of chloride ions in concrete, considering the difference of moisture transport in the process of dry and wet alternating, the convection-diffusion control equation of chloride ion transport in unsaturated concrete is derived.The water diffusion equation and chloride ion convection-diffusion equation are solved numerically by using Crank-Nicolson scheme with high precision.The experimental results are in good agreement with the model calculation results. The results of parameter sensitivity analysis show that the chloride ion concentration decreases with the increase of surface pore saturation and dry / wet ratio of concrete.When the initial saturation of concrete is 0.3, the concentration of chloride ion is the highest.
【作者单位】： 长安大学公路学院;长安大学材料科学与工程学院;
【基金】：国家自然科学基金面上项目(51278059);国家自然科学基金青年基金(51308062)
【分类号】：TU528
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本文编号：1765369