以醇胺类缓蚀剂为电解质的电化学再碱化修复效果研究

研究了醇胺类缓蚀剂辅助电化学再碱化修复碳化钢筋混凝土结构的可行性.采用电化学测试技术及化学分析方法研究了乙醇胺及二甲基乙醇胺缓蚀剂在混凝土中的迁移以及在含有2g/LNaCl+0.01mol/L NaOH的饱和氢氧化钙溶液模拟体系中的缓蚀效果.结果表明:在2A/m2恒电流密度形成的电场作用下,2种缓蚀剂通过30mm厚混凝土的速率明显高于未通电情况,即电场对醇胺类缓蚀剂的迁移扩散过程起到了促进作用.随着乙醇胺及二甲基乙醇胺浓度的增大,其缓蚀效果也逐步提高;相同浓度下二甲基乙醇胺表现出更优异的缓蚀效果,在浓度为0.04mol/L时其对Q235钢筋的缓蚀率达95.78%.二甲基乙醇胺的存在加快了电化学再碱化后钢筋腐蚀电位的正移,钢筋腐蚀电流密度更小,明显地改善了电化学再碱化的修复效果.

Rehabilitation Effects of Electrochemical Realkalization with Alcamines Inhibitors

The feasibility of alcamines inhibitor auxiliary electrochemical realkalization repair techniques for carbonization steel reinforced concrete was investigated. The migration of ethanolamine and dimethylethanolamine(DMEA) in concrete and the inhibition effect of the inhibitors in the simulated system which included 2g/L NaCl, 0.01mol/L NaOH and saturated calcium hydroxide mixed solution were measured by using electrochemical test techniques and analysis methods. The results indicate that the rate of the inhibitors passed through 30mm concrete under the electric field formed by the 2 A/m2 constant current density is significantly higher than the case where no current passed, which shows that the electric field promote the migration of alcamines inhibitor. With the concentration increasing of ethanolamine and DMEA, their inhibition effects are also gradually improved. At the same concentration, DMEA manifested excellent inhibition effect. And the inhibition rate of 0.04mol/L DMEA for Q235 steel is up to 95.78%. The corrosion potential is more positive and corrosion current density(icorr) became smaller when sample is immersed in electrolyte solution with DMEA. Electrochemical realkalization with DMEA could enhance the effects of rehabilitation.