钢筋混凝土电化学脱盐影响因素的研究

Research of Influencing Factors in Reinforced Concrete Subjected to Electrochemical Chloride Extraction

采用双层钢筋混凝土试件、电流密度2 mA/cm2、饱和氢氧化钙溶液为电介质溶液,研究了脱盐处理过程中水灰比对电化学脱盐效果的影响,以及对混凝土中钢筋腐蚀状态的影响。结果表明,随着脱盐时间延长,混凝土中的氯离子浓度逐渐降低;混凝土的水灰比越大,脱盐的效果相对越好。脱盐处理后可使得混凝土中钢筋半电池电位逐渐正移,可使得已经处于锈蚀活化状态的钢筋恢复到非锈蚀活化状态。

In renovation of reinforced concrete structures which suffer rebar corrosion induced by chloride ions, the electrochemical chloride extraction （ECE） is a powerful measure. In the present research, the salt removing effect of ECE on rebar concrete with different water/cement （W/C） ratios, effect of ECE on bonding strength between rebar and concrete, and halfcell potential of rebar in concrete were investigated. Cube concrete specimens with two layers of rebar, current density at 2mA/ cm^2, saturated calcium hydroxide solution as electrolyte were used. The test results show that chloride ions concentration in concrete reduces with ECE treatment time, and the larger the W/C ratio, the better the chloride removing effect is. The bonding strength between rebar and concrete gradually reduces with ECE time. The half-cell potential increases a lot after ECE treatment, this indicates that the corrosion state of rebar in concrete is inert to the corrosion.