地震损伤的锈蚀钢筋混凝土剪力墙玄武岩纤维布修复后抗震性能研究

The seismic performance of existing corroded reinforced concrete structures is of special interest in the seismic evaluation of existing structures in recent years. Because the carbonation of concrete, the steel bars will be corroded in reinforced concrete shear walls. The reinforcement corrosion influences the seismic performance of reinforced concrete shear walls and the whole structure. Few provisions are available for strengthening and retrofitting existing corroded reinforced concrete shear walls and seismically damaged and corroded reinforced concrete shear walls with basalt fiber-reinforced polymers (BFRP) sheet. The research work of this project is based on the study result of reinforcement corrosion and seismic retrofitting of existing structures from the applicant and the financial support of the National Natural Science Foundation of China (NSFC) for young scholar. The cyclic pull-out test, double-lap shear test, and low frequency cyclic tests are used in this project. The following three key problems will be solved: (1) the bond stress-slip relationship between corroded rebars and concrete retrofitted with BFRP sheet under cyclic loading; (2) the bond stress-slip relationship of the BFRP sheet-concrete interface under cyclic and dynamic loading; and (3) the calculation models for seismic performance of corroded reinforced concrete shear walls and seismically damaged and corroded reinforced concrete shears strengthened and retrofitted with BFRP sheet. The influence factors such as corrosion rate of reinforcement, seismically damage, and the measures for retrofitting with BFRP sheets will be included in the calculation models. The result of this project can be used for seismic strengthening and repairing existing corroded reinforced shear walls.

锈蚀钢筋混凝土结构建筑物抗震安全近年来日益得到重视和关注。服役中的钢筋混凝土剪力墙由于混凝土碳化等原因会发生钢筋锈蚀现象，锈蚀影响剪力墙及整体结构的抗震性能。目前还缺乏玄武岩纤维布修复后锈蚀剪力墙及地震损伤的锈蚀剪力墙的抗震性能评价方法。本项目基于申请人近10年来在锈蚀和抗震修复方面的研究工作及青年基金的资助项目开展工作。通过粘结性能试验、低周反复加载试验和仿真分析的方法，重点解决往复荷载作用下锈蚀钢筋与混凝土在玄武岩纤维布修复后粘结滑移模型的构建、往复荷载作用下玄武岩纤维布与混凝土界面动态粘结滑移模型的构建及锈蚀钢筋混凝土剪力墙和地震损伤的锈蚀钢筋混凝土剪力墙在玄武岩纤维布修复后的抗震性能评价方法三个关键科学问题。提出考虑锈蚀率、地震损伤、玄武岩纤维布修复方式等影响因素的锈蚀钢筋混凝土剪力墙抗震性能评价方法。本项目的目的是为锈蚀钢筋混凝土剪力墙的抗震修复方法提供进一步的补充。

钢筋锈蚀是导致混凝土结构耐久性退化的主要原因之一，服役中的钢筋混凝土剪力墙由于混凝土碳化或氯离子侵蚀而发生钢筋锈蚀。锈蚀影响钢筋力学性能，降低了钢筋与混凝土粘结性能，引起混凝土剥落，进而引起钢筋混凝土剪力墙的抗震性能下降，采用玄武岩纤维修复锈蚀钢筋混凝土剪力墙是一种有效的措施。项目通过试验研究、理论分析和仿真分析相结合的手段，开展了往复荷载作用下锈蚀钢筋与混凝土在玄武岩纤维布修复后粘结性能、往复荷载作用下玄武岩纤维布与混凝土界面动静态粘结性能及锈蚀钢筋混凝土剪力墙和地震损伤的锈蚀钢筋混凝土剪力墙在玄武岩纤维布修复后的抗震性能研究。主要工作内容和成果如下：（1）探明了玄武岩纤维布修复后锈蚀钢筋与新浇混凝土的粘结性能变化规律，揭示了相应的机理，构建了考虑纤维布影响的锈蚀钢筋与混凝土和新浇混凝土粘结滑移模型；（2）揭示了玄武岩纤维布与混凝土界面的动态有效粘结长度、不同初始静载荷载作用下的粘结性能和不同加载速率下的粘结性能变化规律，提出了动态有效粘结长度预测模型、不同初始静载和动态加载下的粘结滑移关系预测模型；（3）揭示了不同锈蚀率的钢筋混凝土剪力墙的层间位移角和耗能能力的变化规律和机理，并建立了锈蚀钢筋混凝土剪力墙预测模型；（4）探明了5种加固方式下剪力墙的抗震性能变化规律，并基于桁架-杆理论，提出了剪力墙加固后的承载力预测模型；（5）提出了锈蚀剪力墙采用玄武岩纤维加固时的新型锚固方法，并探明了锈蚀剪力墙玄武岩纤维加固后的承载力变化规律；（6）揭示了不同钢筋锈蚀率和不同地震损伤程度及加固方式影响的剪力墙在玄武岩纤维布修复后的抗震性能变化规律；（7）基于锈蚀钢筋与新浇混凝土的粘结滑移模型和玄武岩纤维布与新浇混凝土的界面力学行为模型，构建了考虑钢筋锈蚀率、地震损伤程度、修复方式等因素影响的地震损伤锈蚀钢筋混凝土剪力墙玄武岩纤维布修复后抗震性能评价体系和修复方法。