碳纤维板综合加固混凝土梁的试验研究

发布时间：2019-03-29 19:58

【摘要】：本文针对8片钢筋混凝土T梁的试验,对碳纤维板加固、外包角钢加固、体外预应力加固以及碳纤维板综合加固混凝土梁的抗裂性能、变形性能、延性以及极限承载能力等方面进行分析,研究碳纤维板综合加固梁的结构机理,探讨碳纤维板与角钢、预应力联合加固的效果与优势。通过八根试验梁的试验破坏现象研究发现,采用角钢-碳纤维板和碳纤维板-预应力筋这两种综合加固方法可有效的提高碳纤维板的锚固效果,保证碳纤维板材的强度得到充分发挥,加固梁受力性能优良。利用角钢受弯变形后的反弹恢复力可靠锚固碳纤维板,形成碳纤维板—角钢综合加固梁,碳纤维板和角钢的协同作用效果良好,可有效的限制裂缝的发展,综合加固梁刚度退化不明显,且大幅提高了梁的承载能力。利用预应力筋的等效荷载可靠锚固碳纤维板,碳纤维板—预应力筋综合加固梁两种材料协同工作良好,预应力加固梁开裂荷载较大,可有效提高结构的刚度,可大幅提高加固梁的承载力。碳纤维板-角钢-预应力综合加固梁试验数据分析研究表明,综合加固梁可充分发挥联合加固优势,大大的改善了加固梁的受力性能,承载力的提高值超过碳纤维板、角钢和预应力筋三者单独加固提高量之和。综合加固梁较单一加固梁,联合加固达到优势互补、综合效果最优的目标。借助软件ABAQUS对8根加固混凝土T梁建立三维非线性有限元模型,对综合加固试验梁进行仿真分析计算,并将分析计算结果与试验结果进行了对比,吻合较好。在碳纤维板-角钢-预应力综合加固梁的模型基础上,探讨加固材料参数变化对综合加固梁受力性能的影响因素分析,弥补了试验数量的不足。通过加固梁受力性能的灵敏度分析方法,探讨综合加固梁的各种加固材料合理取值范围,在混凝土强度等级不变的情况下,该梁加固效果对体外预应力面积,有效预应力度、角钢面积较为敏感。在综合加固梁试验研究的基础上,提出了碳纤维板-角钢-预应力综合加固梁的极限承载力计算公式和刚度计算公式,将理论计算结果与试验结果进行对比,吻合较好；对八根试验梁分别根据挠度法和能量法求出了对应的延性系数,进行延性对比分析,综合加固梁中适当增加角钢面积可明显改善加固梁的延性性能。采用模糊综合评价模型,对各种综合加固方式提出技术性指标和经济性指标综合评估方法,针对不同加固技术要求,评选出最优化加固方案,为实际的加固工程提供最佳加固方案。
[Abstract]:In this paper, the crack resistance and deformation performance of 8 reinforced concrete T-beams strengthened by carbon fiber board (CFRP), external prestressing and composite reinforcement with carbon fiber board (CFRP) are studied, including carbon fiber board (CFRP) strengthening, external prestressing reinforcement and composite reinforcement with carbon fiber board (CFRP). Based on the analysis of ductility and ultimate bearing capacity, the structural mechanism of carbon fiber board (CFRP) composite strengthening beam is studied, and the effect and advantage of CFRP, angle steel and pre-stressed reinforcement are discussed. Through the research on the failure phenomenon of eight test beams, it is found that the anchoring effect of carbon fiber board can be improved effectively by using angle-carbon fiber board and carbon fiber board-prestressed tendons. The strength of carbon fiber plate is fully developed, and the mechanical performance of the reinforced beam is excellent. Using the rebound restoring force of angle steel after bending deformation to anchor the carbon fiber board reliably, the carbon fiber board-angle steel composite reinforced beam is formed. The synergetic effect of carbon fiber board and angle steel is good, and the development of cracks can be effectively restricted by the combination of carbon fiber board and angle steel. The stiffness degradation of the composite strengthening beam is not obvious, and the bearing capacity of the beam is greatly improved. Using the equivalent load of prestress bars to anchor the carbon fiber board reliably, the carbon fiber board-prestressed reinforcement composite strengthening beam works well together, and the cracking load of the prestressed reinforcement beam is larger, which can effectively improve the stiffness of the structure, and the structure stiffness can be improved effectively by the combination of carbon fiber board and prestressed reinforcement. The bearing capacity of reinforced beams can be greatly improved. The experimental data analysis and research of CFRP-angle-prestressed composite strengthened beam show that the composite strengthened beam can give full play to the advantages of the combined strengthening, greatly improve the mechanical performance of the strengthened beam, and the value of bearing capacity is higher than that of the carbon fiber board. The sum of angles and prestressed tendons strengthened separately. Compared with the single strengthened beam, the combined reinforcement achieves the goal of complementary advantages and the best comprehensive effect. The three-dimensional nonlinear finite element model of 8 reinforced concrete T-beams is established with the help of software ABAQUS. The simulation and calculation of the composite strengthened test beams are carried out, and the calculated results are compared with the experimental results. The results are in good agreement with the experimental results. Based on the model of carbon fiber board-angle steel-prestressed composite strengthening beam, this paper discusses the influence factors of the change of reinforcement material parameters on the mechanical performance of the composite strengthened beam, and makes up for the deficiency of the number of tests. Through the sensitivity analysis method of reinforcing beam's mechanical performance, this paper discusses the reasonable value range of all kinds of strengthening materials, and under the condition that the strength grade of concrete is constant, the reinforcement effect of the beam is effective to the area of external prestressing force and the effective prestress intensity. Angle steel area is more sensitive. On the basis of experimental research on comprehensive strengthening of beams, the calculation formulas of ultimate bearing capacity and stiffness of carbon fiber board-angle steel-prestressed composite strengthened beams are put forward. The theoretical calculation results are compared with the experimental results, and the results are in good agreement with the experimental results. According to the deflection method and the energy method, the ductility coefficients of the eight test beams are calculated respectively, and the ductility comparison analysis is carried out. The ductility performance of the strengthened beams can be obviously improved by increasing the angle steel area in the comprehensive strengthening beam. The fuzzy comprehensive evaluation model is used to put forward the comprehensive evaluation methods of technical index and economic index for all kinds of comprehensive strengthening methods. According to the different reinforcement technical requirements, the optimal reinforcement scheme is selected. It provides the best reinforcement scheme for the actual reinforcement project.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU375.1

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