牺牲阳极方式电化学脱盐效率影响因素

外加电流方式电化学脱盐能够有效脱除混凝土内的有害氯离子,但对预应力钢筋混凝土结构不适用,存在可能引起氢脆和减小握裹力的危险以及安装施工、管理不方便和在脱盐期间现场需要有专业技术人员进行操作等缺点;使用牺牲阳极方式电化学脱盐法将钢筋混凝土内的有害氯离子脱除出来,可以克服上述缺点,既适用于普通混凝土,又适用于预应力混凝土。研究通电时间、脱盐装置位置以及取样深度对牺牲阳极方式电化学脱盐效果的影响。结果表明,牺牲阳极方式电化学脱盐在工作3个月后仍能有效地将混凝土内的氯离子迁移到外部的活性填充材料中,且在距阳极500 mm处脱盐效率最高,能达到脱除混凝土试件内有害氯离子的目的,其中混凝土试件表层脱盐效率最高可达60%左右。

Factors influencing efficiency of electrochemical chloride extraction by sacrificial anode

Impressed current electrochemical chloride extraction is effective enough to eliminate the harmful chloride ion in concrete,but it has shortcomings of not applying to the prestressed reinforced concrete structure,being likely to cause the danger of hydrogen embrittlement and decrease bond stress,being inconvenient in installation construction management and needing professional personnels to operate during field desalination.The way of using sacrificial anode electrochemical chloride extraction to move out harmful chloride ion in the reinforced concrete can overcome the above disadvantages,and it is not only suitable for ordinary concrete,but also suitable for prestressed concrete.This paper studies the influence of sacrificial anode electrochemical desalting effect from three aspects including conduction time,desalination device location and sampling depth.The results show that the sacrificial anode electrochemical chloride extraction can effectively remove the chloride ion in the concrete out of the active filler material after 3 months,and at 500 mm from the anode with the highest the desalting efficiency.This method can remove harmful chloride ion out of the concrete sample,and concrete specimen surface desalting efficiency can be raised up to about 60%.