预应力混凝土结构的氯离子二维扩散理论

针对无限大的扩散介质,以综合考虑氯离子结合能力、氯离子扩散系数的时间依赖性和环境温湿度影响的实际预应力混凝土氯离子方程为基础,分别在常数和幂函数边界条件下,推导出二维氯离子扩散理论的齐次模型.同时根据常数边界条件,模拟氯离子在二维的扩散行为,满足实际的边界条件,模拟值与试验值吻合良好.通过试验发现氯离子扩散在相邻两个表面非稳步同时进行的特点,并且分别探讨了水胶比与应力水平对预应力混凝土结构氯离子扩散的影响.

Two-dimensional chloride ion diffusion theory for prestressed concrete structure

Assuming infinite diffusion medium,based on the diffusion equation for prestressed concrete structure,and accounting for the effects of concrete chloride binding capacity,time dependence of diffusion coefficients,temperature and moisture,models of chloride diffusion in two-dimensional infinite body with both power function and constant homogeneous boundary conditions were formulated.For constant homogeneous boundary,two-dimensional chloride diffusion was simulated,which proved to be in good agreement with the experimental results.The characteristic of non-stability and non-simultaneity for two-dimensional diffusion was discovered and the effects of both water-cement ratio and stress to chloride diffusion of prestressed concrete structure were discussed.