FRP格栅-ECC复合抗弯加固锈蚀钢筋混凝土板的力学性能与设计理论研究

Steel corrosion has become a critical problem that seriously threatens the safety of reinforced concrete structures and social economic development. Strengthening and repairing the deteriorated concrete structures should be the first choice considering the sustainable development as well as social and economic benefits. Aiming at the problems of corroded reinforced concrete slab members and secondary corrosion after reinforcement which are seldomly studied at present, this proposed project will thus carry out an experimental and theory approach for the FRP grid reinforced ECC matrix composite layer strengthening the corroded RC slabs to systematically analysis the mechanism and design theory. It reveals the bond-slip relationship and debonding mechanism between FRP grid and ECC as well as the composite layer between the substrate concrete. The improvement method for increasing the interface stress between these three materials will be also provided. Moreover, the strength and stiffness calculation method of flexural strengthening corroded RC slabs will be proposed as well as the design theory and basic method of this strengthening system. The expected achievements of this project can develop the design theory and technical support for the strengthening of deteriorated RC structures. It can have a great contribution to the development of Guangdong, Hongkong and Macau and a practical significance to the national “one belt and one way” marine development strategy.

钢筋锈蚀已经严重威胁混凝土结构安全和国民经济。从可持续发展和社会经济效益角度综合考虑，对受损混凝土结构进行修复加固应是首选措施。针对加固研究较少涉及的锈蚀钢筋混凝土板构件及加固后二次锈蚀问题，本申请项目拟采用新型FRP格栅-ECC复合加固系统对因钢筋锈蚀导致性能劣化的混凝土板进行抗弯加固，采用试验研究与理论分析相结合的方法，系统地研究FRP格栅-ECC抗弯加固锈蚀混凝土板的强化规律和作用机理。揭示FRP格栅-ECC-混凝土三者之间粘结滑移关系，确立三者之间界面剪力传递保障机制。提出抗弯加固板的强度和刚度计算模型，并初步建立FRP格栅-ECC复合抗弯加固体系的基本设计理论和方法。本项目的顺利实施将完善和提升FRP加固技术的理论体系和学术水平，为劣化混凝土结构加固工程的设计和施工提供技术支持。同时，对实现国家“一带一路”海洋开发战略，粤港澳大湾区的建设推进和经济发展有着重大的现实意义。

针对目前锈蚀钢筋混凝土板抗弯加固存在的不足之处，本项目采用了新型FRP格栅-ECC复合加固系统对因钢筋锈蚀导致性能劣化的混凝土板进行抗弯加固，采用试验研究与理论分析相结合的方法，系统地研究FRP格栅-ECC抗弯加固锈蚀混凝土板的强化规律和作用机理。具体进行了包括FPR格栅-ECC复合加固层与混凝土界面粘结性能试验研究；锚固FRP格栅-ECC复合层与混凝土的界面力学行为研究；FRP格栅-ECC复合抗弯加固锈蚀钢筋混凝土板的力学性能研究；FRP-UHPC复合加固锈蚀钢筋混凝土柱的力学性能与设计方法研究。通过试验研究和理论分析相结合，明晰了FRP格栅-ECC-混凝土三者之间粘结滑移关系，确立三者之间界面剪力传递保障机制；找出了锚固件情况下FRP格栅-ECC复合层与混凝土之间的界面性能规律，讨论了锚固件的合理布置方式及其对界面的影响机制；得到了锚固件影响下FRP格栅-ECC抗弯加固锈蚀后钢筋混凝土板的力学性能，并初步建立FRP格栅-ECC复合抗弯加固体系的基本设计理论和方法。在此基础上更进一步拓展了FRP和水泥基复合材料加固锈蚀后构件的可行性和有效性，对处理锈蚀后的钢筋混凝土板提供了非常有效的解决途径。本项目的顺利实施将完善和提升FRP加固技术的理论体系和学术水平，为劣化混凝土结构加固工程的设计和施工提供技术支持。同时，对粤港澳大湾区的建设推进和经济发展有着重大的现实意义。