预应力碳纤维板抗弯加固技术试验研究

发布时间：2018-04-24 05:13

本文选题：碳纤维板 + 预应力　；参考：《中国铁道科学研究院》2015年硕士论文

【摘要】：目前常用的碳纤维材料加固方法,是在构件受拉区粘贴碳纤维板材或布材,这种方法不能充分利用碳纤维材料高强性能。通过预先对碳纤维材料施加预应力可极大提高其强度利用率。采用预应力碳纤维板抗弯加固既有铁路桥梁可显著提高梁体抗裂性能,取得良好的加固效果。本文以碳纤维复合板材为研究对象,对带锚夹具的碳纤维板组装件进行静力、疲劳、松弛和高低温强度试验研究,试验结果表明:碳纤维板静力破断强度在2800MPa以上,高于设计值2600MPa;经过600万次以上加载循环后碳纤维板静力强度降低了7%;经过1000小时后碳纤维板松弛率小于2%;碳纤维材料在-40℃低温环境下静力强度基本不变,在80℃高温环境下静力强度折减了9.1%;可见碳纤维板具有优异的力学性能。采用体外预应力碳纤维板对我国铁路普通高度32m预应力混凝土T梁进行了加固实施,并在加固前后分别进行了理论计算和静载试验,结果表明:与原梁相比,加固后梁的跨中截面消压弯矩提高15.6%,接近理论值14.8%;抗弯加固效果显著,实现了加固设计目标。
[Abstract]:At present, the common method of strengthening carbon fiber material is to paste carbon fiber sheet or cloth in the tensile zone of the component. This method can not make full use of the high strength properties of carbon fiber material. Prestressing the carbon fiber material can greatly improve the strength utilization rate. The flexural reinforcement of the prestressed CFRP board can be significant for the existing railway bridges. In this paper, carbon fiber composite board is taken as the research object, and the static, fatigue, relaxation and high and low temperature strength tests of the CFRP assembly with anchor clamp are carried out. The test results show that the static breaking strength of the carbon fiber board is above 2800MPa and higher than the design value of 2600MPa; after 6 million times. After the loading cycle, the static strength of CFRP was reduced by 7% and the relaxation rate of CFRP was less than 2% after 1000 hours, and the static strength of carbon fiber material was basically unchanged at low temperature -40 C, and the static strength decreased by 9.1% under the high temperature environment at 80 C, and the carbon fiber board had excellent mechanical properties. The external prestressed CFRP plate was used. The reinforcement of the 32m prestressed concrete T beam of ordinary railway height in China is carried out, and the theoretical calculation and static load test are carried out before and after the reinforcement. The results show that, compared with the original beam, the bending moment of the middle cross section of the reinforced rear beam increases 15.6%, close to the theoretical value of 14.8%, and the effect of bending reinforcement is remarkable, and the design goal of reinforcement is realized.

【学位授予单位】：中国铁道科学研究院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72

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