非饱和混凝土氯离子传输模型及参数分析  

Chloride Transport Model and Parameter Analysis of Unsaturated Concrete

作　　者：於德美[1] 关博文[2] 申爱琴[1] 陈华鑫[2] 

机构地区：[1]长安大学公路学院,西安710064 [2]长安大学材料科学与工程学院,西安710064

出　　处：《硅酸盐通报》2017年第4期1130-1135,共6页Bulletin of the Chinese Ceramic Society

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)

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。Most of the concrete structure in entity engineering is always in the unsaturated state with alternating wet and dry seasons. It is of great importance to do the research chloride salt erosion in unsaturated concrete for concrete durability. According to the chloride ion transmission mechanism, the chloride convection-diffusion control equation in unsaturated concrete was derived by considering the difference of moisture transmission the dry-wet alternate process. Crank-Nicolson method was engaged to develop the finite difference format of equation above. The results of proving experiment reveal that the results of model calculation have a good correlation with the measured results. The parameter sensitivity analysis result shows ： chloride ion concentration increases decreases with the increase of dry and wet ratio surface and pore saturation. The chloride ion concentration gets its highest with the concrete initial saturation is 0. 3.

关 键 词：非饱和混凝土 氯离子 扩散 对流 对流区深度 

分 类 号：U414[交通运输工程—道路与铁道工程]