湿度-温度耦合效应下码头CFRP加固桩基钢筋锈蚀特性试验研究及剩余寿命预测

Reinforcement bar corrosion of concrete structure in offshore engineering is a world concerning problem which has become increasingly prominent, especially the pile wharf's pile foundation which suffers wave splashing, tide alternating and temperature changing for long time is prone to cause steel bar corrosion, early destruction and service time reducing. In recent years using Carbon Fiber-Reinforced Polymer (CFRP) which has high strength and excellent corrosion resistance ability to reinforce pile wharf's pile foundation and prevent reinforcement bar corrosion under complex environment is a study of bright prospects in marine engineering. In this research project the humidity-temperature coupled environment system is designed and used to accelerating corrosion of pile strengthened with CFRP, at the same time, combined with theoretical analysis and numerical calculation, the steel bar corrosion morphology under humidity-temperature coupling condition is researched and reinforcement bar corrosion morphology description theory and method is established; the influence law of humidity- temperature coupling and CFRP material to steel bar corrosion is revealed and the progressive corrosion mechanism of pile strengthened with CFRP is also researched; on these basis, the pile rebar's expansion corrosion stage division, definition standard and quantitative analysis theory is explored, the pile's reinforcement steel corrosion prediction model and analysis theory of residual service life under the humidity-temperature coupling condition is built.

近海工程混凝土结构中钢筋锈蚀已成为全世界普遍关注并日益突出的问题，尤其是海港高桩码头桩基长期受浪溅、潮差的干湿交替以及温度变化的影响，其内部钢筋易发生锈蚀破坏，是造成桩基早期破坏，影响码头使用寿命的关键。近年来利用新型碳纤维增强复合材料（CFRP）的高强度和优异耐腐蚀性能加固码头桩基，防止钢筋锈蚀，是目前海工领域一项具有前景的研究。本课题设计干湿交替-温度耦合环境模拟系统进行CFRP加固码头桩基钢筋锈蚀加速试验，结合理论分析、数值模拟方法，研究湿度-温度耦合作用下CFRP加固桩基钢筋锈蚀形态特征，建立CFRP加固桩基钢筋锈蚀的形态描述理论与方法；揭示钢筋锈蚀过程中湿度、温度耦合及CFRP材料对钢筋锈蚀的影响规律，获取CFRP加固桩基钢筋渐进锈蚀机理；在此基础上探索桩基钢筋锈蚀扩展期不同阶段划分、标准界定及其量化分析理论，构建基于湿度-温度耦合下码头桩基钢筋锈蚀剩余寿命预测模型与分析理论。

碳纤维增强复合材料（CFRP）具有超高的强度质量比、施工方便以及优良的耐腐蚀性能，非常适用于恶劣海洋环境中高桩码头混凝土桩基钢筋锈蚀的防腐加固，也是目前海工领域一项具有前景的研究。本课题通过研发干湿交替-温度耦合环境模拟系统与室内桩基钢筋加速锈蚀试验系统，研究了湿度-温度耦合作用下CFRP加固桩基钢筋腐蚀形态特征，获取了湿度-温度耦合作用下，大气区、干湿交替区和水下区高桩码头CFRP加固桩基钢筋锈蚀的形态渐进性演化特征；研究了干湿交替过程、温度周期变化及CFRP加固材料对桩基钢筋锈蚀的影响规律，获得了湿度-温度耦合作用下CFRP加固桩基钢筋渐进锈蚀机理；对桩基渐进性锈蚀过程的不同发展阶段进行划分、标准界定及其量化，并对湿度-温度耦合作用下码头CFRP加固桩基钢筋锈蚀剩余寿命进行了预测。研究结果表明腐蚀桩基以及未腐蚀桩基的抗腐蚀能力相较于未经加固前具有了显著的提高，形成的海洋环境下CFRP加固不同耐久性码头桩基的修复效果、CFRP加固桩基内部钢筋锈蚀规律以及CFRP加固桩基剩余使用寿命的计算方法等内容，为码头桩基的耐久性修复中应用CFRP加固这一先进的技术提供了试验数据和理论参考。