Corrosion assessment of epoxy coated reinforcement in concrete structures

混凝土结构中环氧涂层钢筋的腐蚀评估

• 批准号: 314568399
• 负责人: Professorin Dr.-Ing. Sylvia Keßler
• 金额: --
• 依托单位: Department of Civil and Environmental Engineering
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/314568399?language=en
• 关键词: Corrosion; assessment; epoxy; coated; reinforcement

Reinforced concrete structures are an essential part of our infrastructure. When affected by chloride induced corrosion, service life of these structures is shortened if not maintained properly. Beside conventional black steel as reinforcement epoxy coated reinforcement (ECR) is used especially in North America as a measure to prevent chloride induced reinforcement corrosion. Currently the approval of epoxy coated reinforcement in Germany is in progress. However, no assurance can be given that the coating is defect-free. Corrosion processes in coating defects cannot be excluded but due to the restricted transport process the resulting corrosion rate is limited. If we want to benefit from the advantages of epoxy coated reinforcement we need a scientific basis how to inspect these structures. So, a special effort is necessary to develop and apply precise and accurate inspection methods for corrosion detection. Unreliable inspection data can lead to unnecessarily executed repair actions or, even worse, can lead to a situation that needed repair action on corroding reinforcement is not performed.All electrochemical measurement method (Corrosion Potential, Polarization Resistance, Electrochemical Impedance Spectroscopy, Zero-Resistance-Ampere-Meter) under investigation have their advantages and disadvantages in handling, effort, spatial information (raster or point measurement), reliability etc.. These advantages and disadvantages will be summarized and discussed. The objective is to combine the measurement techniques in this way that a disadvantage of one measurement technique can be compensated by another with the aim to achieve higher inspection reliability. Depending on the inspection issue (defect detection, or detection of corrosion activity) an inspection guideline will be developed considering the combination, extent and order of the resulting reliable electrochemical inspection methods. Finally the beforehand identified inspection methods and inspection procedure will be validated on existing reinforced concrete structures made of epoxy coated reinforcement.In Europe only the two mentioned bridges contain epoxy coated rebar, so the data base is rather limited. In the United States over 65,000 bridge structures are executed with epoxy-coated reinforcing steel bars for corrosion protection. Therefore, to benefit from the knowledge about inspection of ECR structures and for further development of corrosion condition assessment its essential to cooperate with the experts from the US.

钢筋混凝土结构是我们基础设施的重要组成部分。当受到氯化物引起的腐蚀时，如果不进行适当的维护，这些结构的使用寿命会缩短。除了传统的黑钢作为钢筋外，环氧树脂涂层钢筋（ECR）尤其在北美被用作防止氯化物引起的钢筋腐蚀的措施。目前，环氧涂层钢筋在德国的批准正在进行中。但是，不能保证涂层无缺陷。不能排除涂层缺陷中的腐蚀过程，但由于运输过程的限制，导致的腐蚀速率有限。如果我们想从环氧涂层加固的优点中受益，我们需要一个科学的依据来检查这些结构。因此，需要特别努力开发和应用精确和准确的腐蚀检测方法。不可靠的检测数据可能导致不必要的维修操作，甚至更糟的是，可能导致无法对腐蚀钢筋执行所需的维修操作。所有电化学测量方法研究中的腐蚀电位、极化电阻、电化学阻抗谱、零电阻电流计在操作、工作量、空间信息等方面各有优缺点（光栅或点测量）、可靠性等。这些优点和缺点将被总结和讨论。目的是以这种方式联合收割机组合测量技术，使得一种测量技术的缺点可以由另一种测量技术补偿，目的是实现更高的检查可靠性。根据检查问题（缺陷检测或腐蚀活动检测），将制定检查指南，考虑所产生的可靠电化学检查方法的组合、范围和顺序。最后，预先确定的检查方法和检查程序将在现有的环氧涂层钢筋制成的钢筋混凝土结构上进行验证。在欧洲，只有上述两座桥梁含有环氧涂层钢筋，因此数据库相当有限。在美国，超过65，000座桥梁结构使用环氧树脂涂层钢筋进行防腐。因此，为了从ECR结构检测的知识中获益，并进一步发展腐蚀状态评估，与美国专家合作至关重要。