基于ICCP-SS方法的钢筋混凝土连续梁耐久性保障策略研究

The durability problem of RC structures caused by corrosion of reinforcement includes two aspects: the durability of material and the durability of structure. For the former case, impressed current cathodic protection (ICCP) using CFRP has been demonstrated to be an efficient technique for preventing corrosion in the RC structures; while for the latter case, CFRP has also been verified to be capable of improving the capacity of RC structures significantly (i.e. SS-structural strengthening). Therefore, this study aims at taking advantage of both characteristics of CFRP and combining them together as a new repairing technique, termed as the ICCP-SS method. The ICCP-SS repairing method provides a totally new approach for the solution of corrosion problem as well as safety issues of RC members. In this study, this innovative method will be applied to corroded RC continuous beams, which are the most widely used structural members in the construction. This study will investigate the structural behavior of the strengthened RC continuous beams, optimize the ICCP-SS repairing technique and propose rational elastic and plastic design methods. The outcome of this research will allow the application of the ICCP-SS technique from the material level to the member and structure level; hence, it has a promising future on a wide range of engineering applications.

针对钢筋锈蚀引起的混凝土结构耐久性劣化研究，可分为材料耐久性和结构耐久性两个层次。从材料耐久性的角度看，利用碳纤维增强复合材料(CFRP)作为辅助阳极的外加电流阴极保护技术(Impressed current cathodic protection, 简称为ICCP)已被证实可以有效阻止钢筋锈蚀；从结构耐久性的角度看，采用CFRP的结构加固方法可以显著提高混凝土结构承载力。基于上述认识，本课题提出将阴极保护(ICCP)与结构增强（SS-Structural strengthening）有机结合的ICCP-SS方法，通过体系创新实现混凝土结构耐久性的新型保障策略。将此方法应用到实际建筑工程中广泛采用的连续梁超静定结构中，研究结构性能演变规律、优化保障策略与设计方法。课题研究成果将实现ICCP-SS技术从材料到构件，再到结构的一体化研究和应用，具备重要的工程应用前景。

本项目针对钢筋混凝土结构在滨海腐蚀环境下的ICCP-SS（阴极保护及结构加固）保障性策略开展理论、试验与应用研究。基于前期研究中对碳纤维增强符合材料（CFRP）的电化学和力学性能研究成果，以及多重优化的水泥基无机胶凝材料，提出了适用于滨海腐蚀环境中钢筋混凝土结构的ICCP-SS全寿命保障策略。本项目分别研究了ICCP-SS修复后的钢筋混凝土连续梁的性能，揭示了采用碳纤维网格布/水泥基材料/混凝土界面在荷载与腐蚀环境共同作用下的粘结性能，探讨了加固后钢筋混凝土构件的受力破坏模式及应力分布规律，研究了阴极保护对碳纤维有效利用率和超静定结构弯矩重分布的影响，进而建立采用ICCP-SS修复后的钢筋混凝土构件的设计方法。同时，本项目将ICCP-SS体系应用到实际工程中，通过实验室与实际工程结果对比研究，验证ICCP-SS在不同工况下的耐久性能。结合试验研究、数值分析和理论研究，证明了ICCP-SS双重功能全寿命保障策略的可行性和有效性，得到了修复后钢筋混凝土结构的结构设计方法。研究成果为ICCP-SS体系的工程应用提供理论和试验依据，解决滨海腐蚀环境下混凝土结构加固所面临的实际问题。