【作者】 任慧韬；

【导师】 赵国藩；

【作者基本信息】 大连理工大学 ， 结构工程， 2003， 博士

【摘要】 纤维增强复合材料(简称FRP)是一种新型建筑材料，因为其具有强度高、质量轻、易于剪裁施工等优点，在混凝土结构的补强加固领域尤其受到推崇。目前这种新型材料的应用体系在日本、美国已经较为成熟。我国于二十世纪九十年代后期开展FRP的研究应用工作，其中外部粘贴FRP片材加固混凝土结构技术是目前研究的重点和热点。作者结合辽宁省交通厅重点课题“桥梁加固改造新工艺、新技术研究”，针对目前关于FRP加固混凝土结构基本力学性能和长期受力性能研究较少的特点，进行了下面几个方面的研究工作。 1．进行了碳纤维片材和玻璃纤维片材的拉伸性能试验研究。设计了加载装置和测量应变装置，测试6种不同纤维片材和粘结剂组合的抗拉强度、弹性模量、极限应变，并分析不同粘结剂对纤维片材拉伸性能的影响，最后对纤维片材拉伸试验的标准化问题进行了简单的探讨。 2．通过123个混凝土试件与CFRP、GFRP片材的抗剪粘结强度试验结果，分析FRP片材与混凝土发生剪切粘结破坏的全过程以及破坏特征，讨论了粘结力与粘结滑移的关系。同时研究了FRP片材与混凝土粘结面上应力分布特点，并根据试验结果以及前人得到的相关结论，给出了当粘结长度大于有效粘结长度的极限粘结力计算公式，并对计算结果和试验结果以及其他公式计算结果进行比较。 3．根据GFRP片材加固混凝土结构在施工中常涉及到的一些相关因素，如混凝土基层表面处理情况、所选用的粘结剂类型、涂抹粘结剂的厚度、加固的方式以及养护状况，进行了33个混凝土试件与GFRP片材的剪切粘结试验，并进行了采用GFRP片材加固的15根混凝土梁的抗弯试验，分析了与施工性能相关的因素对GFRP片材加固混凝土结构效果的影响。 4．试验研究了工程中常用的碳纤维片材和玻璃纤维片材在水环境、湿热环境、冻融环境、碱化环境下的抗拉强度、弹性模量、极限变形的变化，简单分析各种环境对复合材料性能影响的原因。 5．对于冻融循环对多层纤维增强复合材料之间粘结性能的影响、FRP片材与受到冻害混凝土的粘结性能问题、冻融循环对FRP片材加固混凝土结构整体性能影响问题和湿热环境对FRP片材与混凝土粘结性能的影响问题进行了试验研究。分析了湿热环境、冻融循环对于FRP材料加固混凝土结构的综合影响。 6．试验研究了碳纤维片材的徐变性能，并分析徐变随时间的变化规律，给出拟合的徐变—时间曲线。研究了卸载后碳纤维片材的强度、模量变化情况，分析了徐变性能对加固综合效果的影响以及对预张拉粘贴碳纤维片材加固混凝土结构的影响。更多还原

【Abstract】 Fiber reinforced polymers (FRP) is a new building material, which has been used wildly in strengthening concrete structures due to its high strength, light weight, convenient construction. At present, the researches and the applications have been mature in America and Japan. In China, the study of FRP has been developed since the end of last century, and the technology of strengthening concrete structures with bonding exterior FRP is the focus of study. In this paper, combined with the key program ’Research on the application of new technologies and new methods in strengthening bridge structures’ in Liao Ning province, a series of tests about the basic theories and long time behavior of FRP strengthening concrete structures have been completed, and many conclusions have been obtained.1. Experiments on uniaxial tensile of CFRP and GFRP are carried out, in which the tensile strength, Young’s modulus and ultimate deflection of FRP are measured. The influence on tensile behavior caused by different adhesives is analyzed, and the standardization problem on tensile test methods is discussed.2. Based on 123 specimens results of the shear bond test of FRP and concrete, the failure characteristics of bond test are described, and the relationship of bond strength and bond slip is discussed. The calculation formula of bond strength of FRP and concrete is established according to experiment results and former conclusions, and the comparison is carried out among calculated results, test results, and results from other formula.3. Based on the bond test for 33 concrete specimens and GFRP and bending test for 15 beams strengthening with GFRP, surface preparation of concrete, type of epoxy adhesives, thickness of adhesives, hardening time of adhesives, cure condition after strengthening are considered, and the effect on concrete structures strengthening with GFRP causing by construction behavior was analyzed.4. Based on the fast freeze-thaw test, the alkaline test, the water immersion test and the wet-thermal test of FRP, the influence on FRP mechanics behavior caused by aggressive environments are studied, and the causes of degradation of FRP behavior are simply analyzed.5. These problems that the influence of bond behavior among FRP layers caused by the freeze-thaw action, and bond behavior between FRP and concrete experienced freeze-thaw-III-action are studied by test. In addition, the influence on integral structures by freeze-thawaction and wet-thermal condition is considered.6. The creep behavior of carbon fiber reinforced polymers is studied, and the regularity between time and creep deflection is analyzed. Creep model is established by statistic analysis, as well as the influence on engineering practice and prestressing bonding FRP technique induced by creep behavior of CFRP is analyzed.更多还原