Performance of epoxy-coated reinforcing steel in highway bridges
Performance of epoxy-coated reinforcing steel in highway bridges
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公路桥梁环氧涂层钢筋的性能
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
S. K. Lee
中科院分区：
文献类型：
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作者：
K. C. Clear;W. Hartt;J. Mcintyre;S. K. Lee
进行了实验室、试验场和现场研究，以评估环氧涂层钢筋（ECR）的防腐蚀性能。这项工作包括一个关键的解释性文献综述，考虑ECR生产工厂和工作现场的做法和质量控制方法。测试程序包括从10个来源获得的棒材，并涉及涂层表征、80摄氏度水暴露测试、各种电解质中的化学浸泡测试（环境温度）以及受氯化物污染的混凝土板中ECR的测试场暴露。通过电化学阻抗谱和涂层附着力测试来评估性能。在适当的情况下，还对桥梁施工现场的现场ECR进行了测试。ECR性能在不同的测试根据酒吧的来源而变化，并得出结论，阻抗和溶剂萃取重量损失的涂层性能与长期的腐蚀保护最好的相关性。涂层失效机制被确定为与通过涂层的导电路径、湿粘附损失、阴极剥离和涂层缺陷处的腐蚀（或这些的组合）相关的膜下腐蚀。得出的结论是，一个不可接受的高百分比的涂层评估不会提供长期的腐蚀保护氯化物污染的混凝土运输服务。
Laboratory, test yard and field research studies were performed to evaluate the performance of epoxy-coated reinforcing steel (ECR) with regard to corrosion protection. The effort consisted of a critical interpretative literature review, consideration of ECR production plant and job site practices and quality control methodologies. The testing program included bars acquired from ten sources and involved coating characterization, 80 deg C aqueous exposure testing, chemical immersion testing (ambient temperature) in various electrolytes and test yard exposure of ECRs in chloride contaminated concrete slabs. Performance was assessed by electrochemical impedance spectroscopy and coating adhesion testing. Where appropriate, the testing was also performed upon in place ECRs at bridge construction sites. ECR performance in the different tests varied according to bar source, and it was concluded that impedance and solvent extraction weight loss were the coating properties with which long-term corrosion protectiveness best correlated. Coating failure mechanisms were identified as underfilm corrosion in association with either conductive pathways through the coating, wet adhesion loss, cathodic disbondment and corrosion at coating defects (or combinations of these). It was concluded that an unacceptably high percentage of the coatings evaluated would not provide long-term corrosion protection in chloride contaminated concrete transportation service.