摘要
过去对混凝土腐蚀的研究,其腐蚀液与实际的混凝土孔溶液有较大的差异。采用水泥提取液模拟混凝土孔溶液,通过自腐蚀电位、动电位极化和电化学阻抗谱研究了Ca(NO2)2及商用阻锈剂NNMI和NNRI对混凝土中钢筋氯盐腐蚀行为的影响。结果表明:3种阻锈剂均能有效降低钢筋受Cl-腐蚀的风险,减小腐蚀速率,并能不同程度地提高钢筋腐蚀的临界Cl-浓度;Ca(NO2)2为阳极型阻锈剂,当[NO2-]/[Cl-]为0.62～1.47时,阻锈效果最好,高达98.2%,NNMI和NNRI为以抑制阴极反应为主的综合型阻锈剂,在推荐掺量下,当环境中Cl-浓度为0.03 mol/L左右时,阻锈效率分别可达到85.0%和87.1%。因此,应根据腐蚀环境状况,选用不同的阻锈剂。
The effect of Ca(NO2)2 as well as commercial antirust agents NNMI and NNRI on the corrosion behavior of concrete steel reinforcement in the presence of chlorides was investigated by measuring the corrosion potential, potentiodynamic polarization curves and electrochemical impedance spectra in cement extraction liquid as simulated concrete pore liquid. It was found that all the three antirust agents could effectively reduce the risk of chloride-induced corrosion of the steel reinforcement and decrease the corrosion rate. Besides, they could also increase the critical threshold value of Cl- which caused corrosion of the steel reinforcement. As an anodic antirust agent, Ca(NO2)2 possessed the best antirust performance, showing an inhibitive efficiency of 98.2% when the concentration ratio of NO-2 to Cl- was between 0.62~1.47. NNMI and NNRI were composite corrosion inhibitors which mainly suppressed the cathode reaction, and the inhi-bitive efficiencies of them were 85.0% and 87.1% respectively at a recommended dosage in the presence of 0.03 mol/L Cl-. Antirust agents should be selected according to corrosion environments.
出处
《材料保护》
CAS
CSCD
北大核心
2012年第2期11-14,17,共5页
Materials Protection
基金
国家自然科学基金面上项目(50978085)
江苏省"六大人才高峰"项目(2009218)
中国博士后科学基金(20100481082)
江苏省博士后科研资助计划项目(1002019B)
中央高校基本科研业务费项目(2009B15214)
关键词
腐蚀行为
钢筋
阻锈剂
模拟孔溶液
混凝土
Cl-
电化学技术
corrosion behavior
steel reinforcement
antirust agent
simulated concrete pore liquid
concrete
electrochemical technology
