探讨CFRP不同铺设方式对混凝土抗弯性能的影响

发布时间：2018-03-15 06:35

本文选题：混凝土　切入点：碳纤维布　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：近几年来,通过粘贴碳纤维布来对混凝土结构进行修补、加固的技术发展的非常快,这项技术是对表面出现裂缝或者剥落的混凝土结构的表面粘贴一层碳纤维布来对结构物进行加固。其中应用较多的是在混凝土梁底部(受拉面)粘贴碳纤维布进行受弯加固,以提高梁的整体抗弯承载力。对一些特别重要的结构构件的重要部位,在混凝土浇筑时就预先铺设碳纤维布,对结构的安全性,或出现缺陷的可能性可以降低。本论文研究的内容主要就是针对混凝土浇筑时预先铺设碳纤维布对混凝土性能的研究。本课题通过实验对碳纤维布铺设在混凝土试块的表面和内部对抗弯强度的影响均做了研究。对于铺设在混凝土表面时,对比了用无机粘结剂(氯氧镁水泥)和有机粘结剂(环氧树脂类)粘贴碳纤维布的混凝土试块在高温、常温下的抗折强度,分析了无机粘结剂相对于有机粘结剂的优缺点。同时以两种碳纤维布为原材料,探索了在新拌混凝土内部不同位置以不同方式铺设碳纤维布对混凝土抗弯性能的影响。实验结果表明:①表面粘贴碳纤维布的混凝土试块的抗折强度明显提高,表明粘贴碳纤维布对混凝土结构进行加固确实能很好的达到修补加固的要求;②常温下环氧树脂类有机粘结剂粘结性能较无机粘结剂好,但无机粘结剂基本满足粘贴碳纤维布修补、加固混凝土结构的要求;高温处理后环氧树脂类有机粘结剂的粘结强度损失较无机粘结剂大的多,相比之下,无机粘结剂更适合在高温下作为碳纤维布的粘结剂;③无粘结剂条件下,在砂浆成型时表面粘贴CFRP无法提高混凝土的抗弯性能,砂浆试块在受荷载作用破坏后CFRP与试块是剥离开的;④内铺碳纤维布能够提高混凝土抗弯性能,其中,整体铺设在底层的碳纤维布对提高试件抗弯性能的效果更显著。可以应用在容易开裂或需要一定预防性的结构中。
[Abstract]:In recent years, the technology of strengthening concrete structures has developed very rapidly by using carbon fiber sheets to repair concrete structures. The technique is to attach a layer of carbon fiber cloth to the surface of a concrete structure with cracks or spalling to reinforce the structure. In order to improve the overall flexural bearing capacity of the beam. For the important parts of some particularly important structural members, carbon fiber cloth is prelaid during concrete pouring, which is safe for the structure. The main content of this paper is to study the performance of concrete with carbon fiber cloth prelaid during concrete pouring. The subject is to lay carbon fiber cloth in concrete by experiment. The influence of the surface and interior of the specimen on the flexural strength is studied. The flexural strength of carbon fiber sheets bonded with inorganic binder (magnesium oxychloride cement) and organic binder (epoxy resin) at high temperature and normal temperature was compared. The advantages and disadvantages of inorganic binder compared with organic binder were analyzed. Two kinds of carbon fiber cloth were used as raw materials. The effect of laying carbon fiber sheets in different ways on the flexural properties of fresh concrete is explored. The experimental results show that the flexural strength of concrete specimens bonded with carbon fiber sheets on the surface of 1 / 1 is obviously improved. The results show that the bonding property of epoxy resin organic binder is better than that of inorganic binder at room temperature. However, inorganic binders basically meet the requirements of bonded carbon fiber sheets for repairing and strengthening concrete structures, and the loss of bond strength of epoxy resin organic binders after high temperature treatment is much greater than that of inorganic binders. Inorganic binder is more suitable to be used as binder for carbon fiber cloth at high temperature. When mortar is formed, CFRP can not improve the flexural property of concrete. After the failure of mortar test block under load, CFRP and the test block are peeled off with carbon fiber cloth, which can improve the flexural properties of concrete. The whole carbon fiber cloth laid on the bottom layer is more effective in improving the flexural properties of the specimens. It can be used in structures which are easy to crack or need some preventive measures.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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