为满足社会经济发展的新需求，实现更高性能的工程结构，本文基于用好“好材料”的设计理念，针对复材管约束混凝土（Concrete filled FRP tube，简称CFFT）开展了研究工作。为了提升CFFT复杂工况下（偏压、地震等荷载）的受力性能，本文发展了复材管约束混凝土芯柱（FRP tube confined concrete core，简称FCCC）技术，提出了第三代FCCC，即内嵌预应力钢筋的FCCC（FCCC encased prestressed rebar，简称FCCC-PR），并针对其基础理论、关键构造和应用技术开展了一系列研究。主要研究与创新性成果包括：（1）复材缠绕管的环拉性能与轴压-内压双向受力性能。研究了复材缠绕管环向拉伸性能的测试方法，解决了现有方法中“局部受弯”和“局部削弱”影响准确测量的难题，建议了约束混凝土用复材管环拉性能测试方法；自主研制了复材管轴压-内压双向加载试验装置，开展了复材管双向受力性能研究，厘清了缠绕角、应力比对复材管双向受力行为的影响；提出并开展了模拟复材管在构件中实际受力行为的孪生试验，揭示并准确描述了约束混凝土用复材管的工作机理。（2）复材管约束混凝土本构及新型组件受力性能。基于对复材缠绕管复杂双向受力行为的研究，建立了考虑复材管轴向受压-环向受拉双向受力的约束混凝土分析模型，并提出了简化设计模型；提出并成功试制出FCCC-PR，并获得其中的预应力损失规律；通过复材约束砂浆轴压试验与FCCC-PR受压试验，探明了FCCC-PR的受力机理，获得了其中材料的受力性能与组件整体的受压性能，建议了FCCC-PR的优化设计参数与关键构造。（3）配置FCCC的RC柱受力性能及工程应用。通过试验研究了配置FCCC-PR的新型构件的轴压、偏压、弯曲受力性能，揭示了FCCC-PR的增强机制；以某高层建筑为背景，针对此类新型构件的应用技术开展了研究，提出了实用的节点构造和设计方法，应用使该项目底层柱截面积减少22.6%。论文研究为国家标准《约束混凝土用纤维增强复合材料管》中的试验方法和CECS协会标准《纤维增强复合材料管约束混凝土芯柱应用技术规程》中的设计方法提供了核心支撑，为FCCC的工程应用提供了重要理论基础和关键技术参考，促进了高性能复材组合结构的发展。
To fulfill the demands of the society and construct high-performance engineering structures, based on the principle of “using good matereials well”, study on concrete filled FRP tube (CFFT) is conducted. To enhance the mechanical performance of CFFT under complex loads, e.g. eccentric load and seismic load, the concept of FRP tube confined concrete core (FCCC) is developed in the present dissertation, and the 3rd generation FCCC, i.e. FCCC encased pre-stressed rebar (FCCC-PR) is proposed. Basic theory, key configuration and application method for FCCC-PR are studied. The contents and innovative results of this dissertation is given below:(1) The mechanical performance of FRP tube under hoop tension and combining axial compressive and internal pressure load. Study on hoop tensile performance of FRP tube and test method is conducted. The relevant work removes the negative influence of “local bending moment” and “local notching configuration” on the accuracy of the test result. Finally, a practical hoop tensile test for FRP tube for confining concrete is suggested. An experimental device to realize the combining axial compressive and internal pressure load is designed and manufactured, and the corresponding experiment is carried out. The influence of the winding angle and stress ratio on the mechanical behavior of FRP tube under combining loading is obtained is obtained. Twin tests are proposed and conducted to simulate the actual mechanical behavior of FRP tubes in confined concrete. These tests revealed and accurately described the FRP tube’s actual confining mechanism. (2) Theoretical-oriented model for CFFT and mechanical performance of novel component. Based on the study of the mechanical performance of FRP tube, a theoretical-oriented model for CFFT considering the mechanical behavior of FRP tube under biaxial stress state and a simplified design-oriented model are proposed. FCCC-PR is proposed and developed, and its mechanism and prestress loss is revealed by a series of experiments. Meanwhile, its axial compressive behavior and the mechanical performance of its contents are obtained. (3) Mechanical performance of RC columns with FCCC and its engineering application. The mechanical behavior of RC columns with FCCC-PR under concentric compressive load, eccentric compressive load and flexural load is investigated experimentally, and the enhancing mechanism of FCCC-PR are revealed. Study on the application technology of FCCC is conducted under an application scenario of high-rise building, and practical joint configuration and design method for RC columns with FCCC are proposed, and it’s found that the utilization of FCCC can decrease the area of columns on the bottom few levels by 22.6%.This dissertation provides essential support for the testing methods in Chinese standard " Fiber reinforced polymer composite tubes for concrete filling " and the design methods in the CECS’s standard "Technical specification for FRP tube confined concrete core", setting an essential theoretical foundation and a significant technical reference for the engineering application of FCCC, and promoting the development of hybrid structures utilized high-performance materials.
