电化学修复氢致钢筋混凝土结构延性退化机理与控制

Compared with traditional concrete durability repair methods, electrochemical repair technology can extract harmful ions out of concrete cover and improve the durability of concrete structures significantly. The issue of hydrogen embrittlement during electrochemical repair is a technical bottleneck which preventing the wide application of this technology on high stress concrete structures. The aims of this research project include exploring the factors affecting the cathodic hydrogen evolution, revealing the permeation mechanism of the cathodic hydrogen evolution product into steel bars under different stress state, defining the plastic degenerating mechanism of steel bar containing different content hydrogen, understanding the ductility degenerating mechanism of concrete structures. Finally, the control method for electrochemical repair based on performance index of reinforced concrete members will be proposed. The research methods include theoretical research, finite element simulation and experimental research. The multi-scale research and multidisciplinary intersecting are the features of this project. The research results could control the negative effects of ductility reduction due to hydrogen embrittlement during the electrochemical repair and provide basic theory support for application of electrochemical repair on high stress concrete structures.

电化学修复技术相比传统耐久性修复方法可排除混凝土中有害介质，从而显著提升混凝土结构耐久性，然而修复过程中可能出现的钢筋氢脆问题是阻碍其应用在高应力状态下混凝土结构中的关键技术瓶颈。本项目拟探究影响混凝土结构电化学修复过程阴极析氢源头因素，揭示阴极析氢产物在钢筋内的渗透机理，明确钢筋在不同电化学充氢程度下的塑性降低规律，掌握钢筋塑性降低程度下混凝土结构性能变化特征，提出基于钢筋混凝土构件性能指标约束的电化学修复过程控制方法。研究过程结合基础理论、数值模拟和试验研究等方法，具备多尺度研究和多学科交叉的研究特色。研究成果拟控制电化学修复过程氢致混凝土结构延性降低的负面效应，为电化学修复技术在高应力状态下混凝土结构中的应用提供基础理论支撑。