基于元胞自动机的开裂混凝土氯离子扩散模拟与分析  

Simulation and Analysis of Chloride Ion Diffusion in Cracked Concrete Based on Cellular Automata

作　　者：马俊军 蔺鹏臻[1] 刘应龙 何志刚[1] MA Junjun;LIN Pengzhen;LIU Yinglong;HE Zhigang(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《西南交通大学学报》2022年第2期360-368,共9页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(U1934205,51878323);甘肃省建设科技攻关项目(JK2021-03);甘肃省教育科技创新项目(2021CXZX-568);甘肃省教育厅青年博士基金(2021QB-056)。

摘　　要：为获得氯离子在开裂混凝土中的浓度分布以及分析裂缝形状、分布形式、偏转角度对混凝土中氯离子扩散效应的影响,根据氯离子在开裂混凝土中的扩散机理,利用元胞自动机和均匀化等效分析方法,建立了模拟开裂混凝土中氯离子扩散过程的元胞自动机模型,并利用数值试验对模型中元胞尺寸进行了优化.研究结果表明:在不影响计算精度的情况下,为提高模型的计算效率,推荐采用元胞尺寸大小为0.5 mm;除个别数据外,模型模拟结果、试验结果与有限元分析结果吻合良好,最大偏差不超过10%;“V”形裂缝中氯离子浓度约为矩形裂缝的0.52倍;曲线形裂缝和折线形裂缝中氯离子浓度约为直线形裂缝的0.87倍和0.89倍;当裂缝偏转角从0°分别增大至10°、20°、30°时,裂缝端部氯离子浓度分别减小3.3%、21.9%、29.8%;裂缝对其周围氯离子扩散区域的影响范围与裂缝形状、分布形式和偏转角度无关,对裂缝周围氯离子扩散效应的影响主要集中在裂缝左右18 mm的范围内.In order to obtain the concentration distribution of chloride ions in cracked concrete and analyze the influence of crack shape,distribution form and deflection angle on the chloride ion diffusion in concrete,a cellular automata model for simulating the diffusion process of chloride ions in cracked concrete is established by using cellular automata and homogenization equivalent analysis methods according to the diffusion mechanism of chloride ions in cracked concrete;the cell size in the model is optimized by numerical experiments.The results show that the computational efficiency of the model can be improved with a high calculation accuracy when the cell size of is 0.5 mm.Except for individual data,the model simulation results are in good agreement with the test results and finite element analysis results,and the maximum deviation is no more than 10%.The chloride ion concentration in the"V"crack is about 0.52 times that in the rectangular crack.The chloride ion concentration in curved cracks and broken line cracks is about 0.87 times and 0.89 times that in linear cracks,respectively.When the fracture deflection angle increases from 0°to 10°,20°,and 30°,the chloride ion concentration at the fracture end decreases by 3.3%,21.9%,and 29.8%,respectively.The influence range of the crack on the chloride diffusion zone around the crack is independent of the shape,distribution form,and deflection angle of the crack.The influenced area is mainly concentrated on the range of about 18 mm perpendicular to the crack.

关 键 词：裂缝 元胞自动机 耐久性 混凝土 氯离子 

分 类 号：TU528[建筑科学—建筑技术科学]