摘要
通过分析带裂缝混凝土内的氯离子扩散系数,建立了裂缝处氯离子扩散的数值理论模型,借助有限元数值分析的方法,模拟了带裂缝混凝土内氯离子在的输运过程,主要考察了裂缝特征参数对氯离子扩散过程的影响。数值模拟结果表明,裂缝的存在对氯离子在混凝土中的传输有一定影响,裂缝周围的氯离子浓度明显高于无裂缝混凝土中的氯离子浓度,与裂缝的距离越大,截面上的氯离子浓度越低,而裂隙频数的增加,加强了氯离子在混凝土中的扩散过程;裂缝的宽度、深度及侵蚀时间对氯离子在混凝土中的扩散有一定的影响,其中裂缝宽度的变化比较敏感,随着侵蚀时间的增加,氯离子的浓度随裂缝宽度的增加而增大;当裂缝宽度介于上下限值之间时,裂缝深度的变化对氯离子浓度的影响的不敏感,裂缝深度的变化在裂缝宽大于上限值时,对氯离子的浓度分布影响较大。
Analysis of chloride ion diffusion coefficient in cracked concrete, establish the numerical mode of the chloride ion diffusion in cracked concrete.By means of the finite method, simulates the.transmission process of chloride ions in fractured concrete in order to ex- amine the influence of the single, multiple cracks, the frequency of the crack, crack width and height in process of the chloride ion diffu- sion.The simulation results show that cracks in the concrete have a certain influence of chloride ions transmission, and the chloride ion con- centration of the fracture section and the surrounding concrete is significantly higher than the intact concrete.Accompany with the increase of distance to cracks, the chloride ion concentration gradually decrease, and the increase of cracking frequency strengthen the process of chloride ion diffusion in the concrete.At the same time crack width, depth and erosion of the time have a certain influence on chloride ion diffusion, and the change of the crack width is sensitive, with the increase of corrosion time, the concentration of chloride ion increases with the increases of cracking width.When the crack width between upper and lower limit, the change of crack depth is not sensitive to the effects of chloride ion concentration.But the crack width is greater than the threshold value, the change of crack depth of have greater influ- ence on the distribution of chloride ion concentration.
出处
《混凝土》
CAS
北大核心
2016年第11期68-72,82,共6页
Concrete
基金
国家自然科学基金资助项目(51178069)
关键词
裂缝
混凝土
氯离子
扩散
数值模拟
crack
concrete
chloride
diffusion
numerical simulation
