氯盐侵蚀作用下TRC加固承载梁弯曲性能的研究

发布时间：2018-05-24 15:36

本文选题：纤维编制网增强混凝土(TRC) + 修复加固　；参考：《中国矿业大学》2017年硕士论文

【摘要】：纤维编织网增强混凝土(Textile Reinforced Concrete,TRC)具有良好的承载、限裂和耐腐蚀的能力,适合应用于严酷环境下混凝土结构的修复加固。TRC的这些优点使其在建筑结构中具有广泛的应用前景。目前,关于常规环境下TRC加固混凝土结构力学性能研究较多,但关于其在腐蚀环境下的力学性能和耐久性能的研究还较少,尤其在承载加固条件下的研究也未见公开报道,这在一定程度上限制了TRC的应用。本文主要研究了氯盐干湿循环作用下TRC加固未承载钢筋混凝土(Reinforced Concrete,RC)梁和承载RC梁的受弯性能。未承载加固梁考虑了氯盐干湿循环及其与弯曲应力耦合作用等因素对加固梁受弯性能的影响。承载加固梁考虑了加固时承载应力大小、加固方式、纤维编织网种类、短切纤维掺量、盐水浓度、干湿循环及其与弯曲应力耦合作用等因素对加固梁受弯性能的影响。最后,基于试验结果,给出了氯盐条件下TRC加固RC受弯梁分析理论的计算公式。对未承载加固梁的研究结果表明,随着干湿循环次数的增加,梁的最大裂缝宽度和跨中挠度增加,而开裂荷载、屈服荷载和极限荷载有降低趋势;随着腐蚀时弯曲应力的增大,梁的最大裂缝宽度会增加,屈服荷载和极限荷载会有所降低。在0.5弯曲应力的条件下,梁的裂缝宽度、极限荷载都有较大的下降。受持载腐蚀时初始挠度的影响,在同级加荷试验下梁的跨中挠度有所降低。对承载加固梁的研究结果表明,在0.2和0.4承载应力加固梁时,TRC加固能起到很好的作用,使梁的裂缝宽度和挠度得到改善,增加了梁的承载力,但是在0.6承载应力时,TRC加固梁破坏模式的改变造成梁的整体性能有较大程度降低。使用预制TRC加固梁,在破坏形态上稍有不同,但在承载力提高和挠度控制上和现浇TRC相差不大,所以预制TRC加固梁也是可以应用到实际工程中的。使用碳纤维编织网制成的TRC在加固RC梁时承载力方面优于玄武岩纤维编织网制成的TRC,细粒混凝土中掺加短切纤维使得加固效果有所加强。随着盐水浓度和干湿循环次数的增加,梁的裂缝宽度和挠度有增大趋势,梁的承载力有所降低;随着腐蚀时弯曲应力的增大,梁的极限承载力有所下降,裂缝宽度有增大的趋势,但是钢筋屈服前梁的裂缝宽度和挠度控制较好。基于极限分析理论和试验结果,给出了氯盐干湿循环下TRC加固混凝土梁的极限承载力公式,采用公式得到的计算结果与试验结果吻合良好。
[Abstract]:Textile Reinforced Concrete (TRC) has good bearing, crack resistance and corrosion resistance. It is suitable for the application of concrete structures under harsh environment to repair and reinforce.TRC. These advantages make it widely applied in the construction structure. At present, the structure force of TRC reinforced concrete under the conventional environment There are many studies on the performance of the study, but there are few studies on the mechanical and durability of the corrosion environment, especially in the study of the loading and strengthening conditions. This has limited the application of TRC to a certain extent. This paper mainly studies the reinforcement of the unloaded reinforced concrete (Reinforced C) by the dry and wet cycle of chlorine salt. The flexural performance of oncrete, RC) beams and bearing RC beams. The effects of the dry and wet cycle of chlorine salt and the coupling effect of the bending stress on the flexural properties of the reinforced beams are considered. The bearing and reinforcement beams consider the size of the bearing stress, the strengthening method, the type of fiber weave, the amount of short cut fiber, the concentration of brine, the dry and wet cycle. The influence of the coupling effect of the bending stress on the flexural performance of the reinforced beam. Finally, based on the test results, the calculation formula for the analysis theory of the bending beam strengthened with TRC under the chlorine salt condition is given. The results of the study on the unloaded reinforced beams show that the maximum crack width and the mid span deflection of the beam increase with the increase of the number of dry and wet cycles. The cracking load, the yield load and the ultimate load tend to decrease, with the increase of the bending stress, the maximum crack width of the beam will increase, the yield load and the ultimate load will be reduced. Under the condition of 0.5 bending stress, the crack width and ultimate load of the beam are greatly reduced. Under the same grade loading test, the span deflection of the beam is reduced. The results of the study on the reinforced beam show that the TRC reinforcement can play a very good role in the 0.2 and 0.4 stress reinforcement beams. The crack width and deflection of the beam are improved and the bearing capacity of the beam is increased, but the failure mode of the beam strengthened by the TRC reinforcement is caused by the 0.6 loading stress. The overall performance of the beam is greatly reduced. The use of prefabricated TRC beams is slightly different in the form of failure, but there is little difference between the bearing capacity and the deflection control and the cast in place TRC. So the precast TRC reinforced beam can also be applied to the actual project. The bearing capacity of the TRC used in the reinforcement of the RC beam is better than that of the RC beam. With the addition of short cut fiber in the TRC of basalt fiber weave, the reinforcement effect is strengthened. With the increase of brine concentration and the number of dry and wet cycles, the crack width and deflection of the beam are increased, the bearing capacity of the beam is reduced, and the ultimate bearing capacity of the beam decreases with the increase of the bending stress. The width of the seam is increasing, but the crack width and deflection of the beam are well controlled. Based on the limit analysis theory and test results, the formula of the ultimate bearing capacity of the concrete beams strengthened with TRC under the dry and wet cycle of chlorine salt is given. The calculation results obtained by the formula are in good agreement with the test results.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU37

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