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为提高碳纤维布加固RC结构的效果及其可靠性,提出了预应力碳纤维布与预紧螺栓联合加固技术。结合在役RC梁的损伤特点及目前的RC梁加固方法,分别采用不同的碳纤维布加固技术对完整梁和破坏梁的抗弯性能进行了对比试验研究。针对目前碳纤维布张拉设备的缺陷,研发了便于现场应用的新型碳纤维布布张拉设备,分析了预应力大小对加固效果的影响。结果表明,预应力碳纤维布及预紧螺栓联合加固技术是一种更可靠的桥梁加固方法,不仅能够提高RC梁正截面的抗弯承载能力及正常使用阶段的截面刚度,而且螺栓预紧锚固碳纤维布能够很好地抑制其在混凝土表面的剥离,提高碳纤维布与混凝土表面之间粘结强度,对碳纤维布施加预应力能够充分发挥其高强性能,有效抑制混凝土裂缝开裂和开展。
In order to improve the effect and reliability of RC structure reinforced with carbon fiber sheet, a pre-stressed carbon fiber cloth and pre-tightening bolt are combined to reinforce the structure. Combining the damage characteristics of existing RC beams and the current RC beam reinforcement methods, the different CFRP reinforcement technologies were used to compare the flexural performances of intact beams and failure beams. In view of the defects of the current carbon fiber cloth tensioning equipment, a new carbon fiber cloth tensioning device is developed for field application, and the influence of the prestressing force on the reinforcement effect is analyzed. The results show that prestressed carbon fiber cloth and pre-tightening bolt joint reinforcement technology is a more reliable method of bridge reinforcement, which not only can improve the flexural load carrying capacity of normal section of RC beam and the section rigidity of normal use stage, The cloth can restrain its peeling on the concrete surface well and improve the bond strength between the surface of the carbon fiber cloth and the concrete. Prestressing the carbon fiber cloth can fully exert its high-strength property and effectively crack and crack the concrete.