建立了电场作用下混凝土内部离子迁移模型;结合混凝土的试验参数和经验常数,确定合适的边界条件,理论分析了电化学除盐过程中混凝土内部Cl-和Na+的迁移规律;将电化学除盐后混凝土内部不同部位Cl-含量和Na+含量与模拟结果进行比较分析。结果显示,模拟结果和实测结果一致,验证了模型的有效性和合理性。其规律为:电场作用一段时间后,氯离子在试件径向呈现上凸曲线分布,即在混凝土内某个部位Cl-含量出现极值;随着电流作用时间的延长,混凝土内部Cl-含量逐渐降低,且Cl-的排除速率逐渐减小,而Na+逐渐在钢筋附近混凝土中聚集。
In this paper,the model of ions migration in concrete has established under the electric field.Na+,Cl-ions migration law was analyzed theoretically during the process of electrochemical chloride extraction(ECE) based on the experimental parameters,empirical constants and suitable boundary conditions.The content of Na+ and Cl-ions in concrete after ECE is agree with simulating results,which shows the model of this paper is effective and reasonable.Both experimental results and simulating results indicate that distribution profile of Cl-ions in the radial direction is the convex curve under electric field,and with the max value of Cl-content appears at a certain position in concrete.With growth of the treatment time,both Cl-ions content in concrete and extracted rate of Cl-ions decline,while Na+ ions gradually aggregates close to reinforcement.