氯离子侵蚀混凝土及细观参数影响的近场动力学模拟  

Peridynamic simulation of chloride penetration into concrete and the influences of meso-scopic parameters

作　　者：李万金[1] 郭力[1] 周鑫[1] 洪俊[1] Li Wanjin;Guo Li;Zhou Xin;Hong Jun(Jiangsu Key Laboratory of Engineering Mechanics, Southeast University, Nanjing 210096, China)

机构地区：[1]东南大学江苏省高校工程力学分析重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2021年第1期30-37,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51578142);国家重点研发计划资助项目(2018YFD1100401).

摘　　要：为了研究混凝土细观参数对氯离子扩散过程的影响,建立了饱和混凝土中氯离子扩散的近场动力学细观模型.该模型采用氯离子浓度的积分代替经典局部模型中的浓度空间微分,使用“键”将氯离子从一个材料点输运到另一个材料点.通过与有限元模型计算结果进行对比,验证了模型的可行性和有效性;讨论了骨料分布、骨料体积分数、骨料级配、界面过渡区(ITZ)厚度和ITZ扩散系数等细观参数对氯离子扩散过程的影响.结果表明:骨料分布对氯离子扩散过程的影响可忽略;随着骨料体积分数的增加,氯离子扩散速度先减小后增大;而骨料级配与氯离子扩散速度没有明显相关度.同时,随着ITZ厚度和ITZ扩散系数的增加,氯离子扩散速度小幅增加.To investigate the effects of meso-scopic parameters of concrete on chloride diffusion,a peridynamic(PD)model for chloride diffusion in saturated concrete at meso-scale is developed.In the PD model,the spatial derivatives of the chloride concentration in the classical local model are replaced by the integral formulation with respect to chloride concentration,and the PD bonds are like pipes transporting chloride ions from one material point to another.Compared with the results of the finite element model,the feasibility and efficiency of the proposed model are verified.In addition,the influences of the meso-scopic parameters including aggregate distribution,aggregate volume fraction,aggregate gradation,the thickness and diffusivity of the interfacial transition zone(ITZ)on chloride diffusion are studied.The results indicate that the aggregate distribution has a negligible influence on chloride diffusion.Additionally,chloride diffusivity firstly decreases and then increases with the increase of the aggregate volume fraction.However,there is a little correlation between chloride diffusivity and aggregate gradation.Meanwhile,chloride diffusion increases slightly with the increase of ITZ thickness and ITZ diffusivity.

关 键 词：近场动力学 细观参数 氯离子扩散 混凝土 

分 类 号：O35[理学—流体力学]