基于水泥基材料铺覆层机敏特性的钢筋混凝土阴极保护研究

In common corrosion protection technology of reinforced concrete, cathodic protection technology is recognized as the ideal one. Based on electrical and thermoelectric characteristics of cement-based materials, functional cement-based materials are firstly prepared by incorporating tellurium, bismuth telluride thermoelectric enhancement and carbon nanotube, carbon fiber conductive fillers into mixed cement matrix in the project. The effects of smart filler content, water-cement ratio, age, environmental temperature and humidity and other internal and external factors on mechanical, electrical, thermoelectric properties of cement-based materials are systematically studied. And the optimal proportion program and preparation technology are put forward. Secondly, design smart cement-based materials to work both as temperature difference auxiliary power and as draping style conductive auxiliary anode combined with outside power supply to build a cathodic protection system for reinforced concrete. Finally, use electrochemical methods electrochemical noise, Mott-Schottky method compared with half-cell potential to evaluate the cathodic protection effect of reinforced concrete. This project will realize low cost, low energy consumption and high durability of the cathodic protection system for reinforced concrete, improve and optimize the existing cathodic protection technology and evaluation methods. It will also provide cost-effective corrosion protection technology for large amount of domestic chloride contaminated bridge engineering, hydraulic engineering, coastal and ocean engineering structures, which has significant economic benefits and application prospect.

常用钢筋混凝土腐蚀防护技术中，阴极保护技术是公认最理想的一种。本项目首先从水泥基材料导电、热电等机敏特性出发，通过在水泥基体中混杂掺入碲、碲化铋等热电增强相和碳纳米管、碳纤维导电组分制备功能性水泥基材料。系统分析机敏组分含量、水灰比、龄期、环境温湿度等内外部因素对水泥基机敏材料力学、电学和热电性能影响，提出最优配比方案和制备工艺。其次设计水泥基材料既作为温差辅助电源，又作为铺覆式导电辅助阳极，并与外界电源建立阴极保护体系对钢筋混凝土实施阴极保护。最后利用电化学噪声、Mott-Schottky法与半电池电位等电化学方法对比研究钢筋阴极保护效果和作用机理。本项目研究将实现钢筋混凝土阴极保护系统的低成本、低能耗以及经久耐用，对现有阴极保护技术和评价方法进行改善和优化，为国内量大面广氯盐腐蚀的桥梁工程、水利工程、近海及海洋工程结构提供经济有效的腐蚀防护技术，具有显著的经济效益和应用前景。

采用阴极保护技术对腐蚀环境中的钢筋进行防护和修复，能有效提高钢筋混凝土结构耐久性，延长工程结构服役寿命。基于碳纤维水泥基材料渗流导电现象和热电效应基本理论，通过在水泥基体中混杂掺入碳纳米管和碳纤维；碲化铋和碳纤维导电组分制备功能性水泥基材料。研究了机敏组分含量、龄期、环境温湿度等因素对水泥基机敏材料力学、电学和热电性能影响，并提出最优配比方案和制备工艺。将优选制备的碳纳米管-碳纤维/水泥基材料作为铺覆式导电辅助阳极，并与外界电源建立阴极保护体系以对钢筋混凝土实施阴极保护。应用腐蚀电位、腐蚀电流和交流阻抗谱研究了钢筋阴极保护效果和作用机理。试验结果表明：在外加温差电流作用下，采用碳纳米管-碳纤维/水泥基材料铺覆层作为辅助阳极能对钢筋提供有效的保护。本项目研究立足提升国内量大面广氯盐腐蚀的桥梁工程、水利工程、近海及海洋工程结构耐久性，实现钢筋混凝土阴极保护系统的低成本、低能耗以及经久耐用，具有显著的经济效益和应用前景。