【作者】 史丽远；

【导师】 夏品奇；

【作者基本信息】 南京航空航天大学 ， 工程力学， 2007， 博士

【摘要】 用复合玻璃纤维增强布加固钢筋混凝土结构是一种高强高效的加固新技术,具有广泛的应用前景和实用价值。本文开展了用复合玻璃纤维增强布加固钢筋混凝土梁的性能的实验和理论研究,建立了该类加固梁的有关粘结性能、抗弯抗剪性能和疲劳性能的分析方法。研究内容包括:(1)研究了正拉、双剪、弯拉三种受力状态下的静载粘结性能。分析了混凝土强度等级、纤维布粘贴层数及粘结长度等因素对其正拉粘结强度、粘结有效长度和承载能力的影响;分析了纤维布的拉应变及平均剪应力的分布规律,得到有效粘结长度及弯拉破坏时纤维布的最大应变,提出了抗剪粘结承载力计算公式;进行非完全粘结和重复载荷作用的粘结性能试验,提出了非完全粘结情况下极限承载力的计算公式。(2)研究了复合玻璃纤维增强布加固钢筋混凝土梁抗弯性能和加固效果。分析了复合玻璃纤维增强布对加固梁的承载力、刚度及裂缝分布等方面的影响;分析了钢筋混凝土梁配筋率及粘贴纤维量对抗弯加固效果的影响;提出了纤维布的设计应变取值和抗弯加固设计公式。(3)研究了复合玻璃纤维增强布加固钢筋混凝土梁的抗剪性能和加固效果。分析了不同包裹方式、不同纤维布粘贴量对抗剪加固效果的影响;提出了纤维布的设计应变取值和抗剪加固设计公式。(4)采用有限元模型模拟加固梁的加载全过程,建立了用复合玻璃纤维增强布加固钢筋混凝土梁的有限元建模关键技术,有限元计算值与试验值吻合较好。(5)研究了在常幅疲劳载荷作用下复合玻璃纤维增强布加固钢筋混凝土梁的抗弯疲劳性能。分析了加固梁的跨中挠度和疲劳裂缝的变化规律,建立了这些参数与载荷水平和载荷循环次数之间的相互关系;获得了疲劳抗弯刚度降低系数的表达式;得到了载荷水平、载荷循环次数之间的回归曲线;分析了复合玻璃纤维布对钢筋混凝土梁的疲劳加固效果。更多还原

【Abstract】 It is a new and effective strengthening technology to use the composite fiberglass reinforced cloth (CFRC) to strengthen the reinforced concrete structures, which is widely applicable in structural engineering. In this thesis, the behaviors of the reinforced concrete (RC) beams strengthened by using the CFRC were investigated experimentally and theoretically. The analytical methods for the relevant bonding, bending, shearing and fatigue behaviors of the CFRC strengthened RC beams have been established. The investigation was focused on as follows:(1) The static bonding behaviors of the CFRC strengthened RC beams under the condition of tension, double-shearing and bending-tension. The influences of the concrete strength grade, thickness of CFRC and bonding length on the bonding strength, bonding effective length and load carry capacity were analyzed. The distribution regulation of CFRC tension strain and averaging shear stress were discussed in detail. The effective bonding length and CFRC maximum tension strains were obtained and the formulas of bonding load carry capacity for resistant shear were presented. The incomplete bonding behaviors and the cyclic bonding behaviors were studied to give the calculating formula of ultimate load carry capacity under the condition of incomplete bonding.(2) The bending performance and strengthening effects of the CFRC strengthened RC beams. The influences of CFRC on the load carry capacity, stiffness and cracks distribution of the strengthened RC beams were analyzed by considering the ratio of reinforcing bar and CFGC thickness. The CFRC design strain value and strengthening design formulas for resistant shear were presented.(3) The shearing performance and strengthening effects of the CFRC strengthened RC beams. The influences of bonding mode and shear span ratio on the strengthening effect for resistant shear was investigated. Based on these results, the CFRC design strain value and strengthening design formulas for resistant shear were presented.(4) The simulation of loading procedures on the CFRC strengthened RC beams by using finite element model. The key simulation skills of finite element modeling for the CFRC strengthened RC beams were established. The simulation results were agreed well with the test results. (5) The fatigue behaviors of the CFRC strengthened RC beams. Based on the experimental results, the changing laws of deflection in the middle span and the fatigue cracks of the strengthened RC beams were analyzed. The relationships of the deflection and cracks with the applied load and cyclic numbers, and the expression of reducing coefficients of the fatigue bending stiffness have been established. The fatigue strengthening effect of the CFRC strengthened RC beams was analyzed.更多还原