混凝土在电化学除盐过程中内部离子迁移和结构变化的研究

Study on the Migration of Internal Ions and the Change of Structure of Concrete during Electrochemical Chloride Extraction

研究了电化学除盐过程中通电量、电解质溶液的性质等对驱除Cl-效率的影响,并利用压汞试验方法(MIP)对经电化学脱盐处理的混凝土孔结构进行了分析。结果表明,经电化学除盐后钢筋附近混凝土的总孔隙率增大,其中小于30nm的孔明显增多,而大孔数量则有所减少;远离钢筋的混凝土的孔隙率变化与所用电解质溶液有关,以水作除盐介质时孔隙率增大,而采用饱和Ca(OH)2和饱和Ca(OH)2+0.001mol/L Li2B4O7溶液时混凝土孔隙率减少。

The influences of desalination parameters such as electric current density and types of electrolytes on the efficiency of chloride extraction are studied. And through the Mercury Intrusion Porosimetry＇s method, the pore size distribution is analysed after ECE. The rezults show that, the porosity of mortar adjacent to the steel bar is increased, and the pores became smaller and more frequent. However, the changes of mortar porosity at the external concrete are correlated with the type of electrolytes to be used. An increase of porosity was discovered in distilled water treated sample, and a decrease exists in saturated aqueous Ca（OH）2 and saturated Ca （OH）2＆0.001mol/L Li2B4O7 treated samples.