Calculation of ion diffusion coefficient related to concrete deterioration based on Debye-Hückel-Onsager theory  

基于Debye-Hückel-Onsager理论的混凝土中离子扩散系数的计算(英文)

作　　者：左晓宝[1,2] 孙伟[1] 李华[1] 周文键[2] 

机构地区：[1]东南大学江苏省土木工程材料重点实验室,南京211189 [2]南京理工大学土木工程系,南京210094

出　　处：《Journal of Southeast University(English Edition)》2010年第4期569-573,共5页东南大学学报（英文版）

基　　金：The National Basic Research Program of China(973Program)(No.2009CB623203);the National Natural Science Foundation of China(No.51078186);Program for Special Talents in Six Fields of Jiangsu Province(No.2008169);the Natural Science Foundation of Jiangsu Province(No.BK2010071);China Postdoctoral Science Foundation(No.200902500)

摘　　要：This paper applies the Debye-Hückel-Onsager electrolyte solution theory to investigate the diffusivity of ions in concrete pore solutions.First,a model of the diffusion coefficient associated with the ionic species,solution concentration and ambient temperature is proposed in the saturated concrete.Secondly,as an example,the effects of sodium chloride solution concentration,which are associated with influencing factors such as the ionic cloud radius,electrophoresis and relaxation,on the chloride diffusion coefficient are analyzed.It is found that the diffusion coefficient decreases with the increase in solution concentration,and the electrophoresis and ionic cloud radius are two important factors influencing the ionic diffusivity.Finally,the experiments,in which the chloride diffusion coefficients in specimens under different water-cement ratios are measured by the rapid chloride migration（RCM）method,are carried out to validate the effectiveness of the proposed model,and the results indicate that there is a generally reasonable agreement between the experimental and the proposed model results.将Debye-Hckel理论和Onsager电导理论用于研究混凝土孔溶液中离子的扩散规律.首先,建立了饱和混凝土中离子扩散系数的计算模型,该模型考虑了离子的种类、孔溶液中离子的浓度、环境温度等因素对离子扩散系数的影响.其次,以孔溶液中氯化钠的浓度变化为例分析了离子氛半径、松弛效应、电泳效应等对孔溶液中氯离子扩散系数的影响规律,发现氯离子的扩散系数随氯化钠溶液浓度的增加而减小,离子氛半径和电泳效应是影响氯离子扩散性能的重要参数.最后,通过RCM法测定了不同水灰比混凝土的氯离子扩散系数,并将模型的计算结果与实测结果进行了对比,以验证模型的合理性,结果表明所建立的模型与实测结果较为符合.

关 键 词：ion diffusion coefficient Debye-Hückel-Onsager theory rapid chloride migration（RCM）method CONCRETE 

分 类 号：TU528[建筑科学—建筑技术科学]