用丝束电极研究混凝土中钢筋腐蚀的不均匀性

STUDY ON NON-UNIFORM CORROSION OF REBAR EMBEDDEDIN CONCRETE BY WIRE-BEAM ELECTRODE

用8×8阵列丝束电极模拟研究了混凝土中钢筋的腐蚀.将混凝土试样浸泡在10 %NaCl溶液中,通过测量铁丝束电极的自腐蚀电位和极化电阻,获得了在相同埋置深度和不同埋置深度时,铁丝腐蚀的电位、极化电阻和腐蚀速度分布等信息,研究了混凝土结构和氯离子浓度对它们的影响.结果表明,混凝土中铁丝腐蚀不均匀.自腐蚀电位和极化电阻较分散,电位随时间负移、极化电阻变小,丝束之间的电位差增大.随铁丝埋入深度增加,电位负移量、氯离子浓度和腐蚀速度都减小。

The corrosion of rebar in concrete was studied by 8×8 liner wire-beam electrode.The corrosion potential,polarization resistance and corrosion rates distributions of wire-beam electrode in the same or different depth were obtained by estimated corrosion potential and polarization resistance in 10% NaCl solution.The effect of chlorine ion concentration and the structure of concrete on them were studied.The results showed that the corrosion of iron wires in concrete were non uniform.The corrosion potential and polarization resistance were scattered.With the increase of immersion time,the corrosion potential shifted negatively,the polarization resistance reduced and the difference of corrosion potential became larger.With increasing the embedded depth of iron wire,the negative shift value of corrosion potential,chlorine ion concentration and corrosion rates reduced,but polarization resistance increased.