高温干湿交替环境下FRP-混凝土界面粘结性能的耐久性研究

发布时间：2018-04-01 05:05

本文选题：FRP　切入点：FRP-混凝土界面　出处：《哈尔滨工业大学》2013年硕士论文

【摘要】：FRP加固混凝土技术受到了越来越多的学者以及工程人员的关注。FRP加固混凝土结构一般在室外，在腐蚀环境作用下，这些结构的耐久性如何，怎么对FRP加固构件进行耐久性设计，这些问题又制约着FRP加固混凝土技术的发展与推广。本文从材料（FRP、树脂、混凝土材料本身）劣化到界面劣化（FRP与树脂和FRP与混凝土两种界面的耐久性），系统分析了FRP混凝土界面粘结性能的耐久性。本文主要包括了以下研究内容：对材料的耐久性研究是对界面耐久性研究的基础，本文通过力学实验和微观实验研究高温干湿交替环境对碳纤维、玻璃纤维和树脂的拉伸性能以及混凝土的抗压强度的影响规律。研究结果表明：在300次高温干湿循环作用下，碳纤维的抗拉强度没有下降，断裂伸长率略有下降；玻璃纤维的抗拉强度和断裂伸长率下降较多，二种FRP的弹性模量基本保持不变；宏观和微观实验结果都表明树脂延迟固化效应在干湿循环早期对树脂的力学性能有较大影响；混凝土的抗压强度基本没有下降。 FRP与树脂之间的良好的粘结性能是保证FRP能有效的加固混凝土结构的前提条件之一，本文通过对60个FRP搭接试件在不同高温干湿循环次数下剪切试验以及微观实验，发现短时间的高温干湿交替环境对FRP与树脂的界面粘结性能的影响很小，多涂胶、适当的选用表面较粗糙和纤维丝之间间隙大一些的FRP能有效的提高FRP与树脂的界面的耐久性。外贴FRP加固混凝土整体性能直接受到FRP与混凝土界面粘结性能的影响，本文通过对60个FRP粘结混凝土单剪试件在不同高温干湿环境下的单剪试验，以此来研究该界面的劣化，并结合已有的界面粘结强度模型，找到了影响界面粘结强度的相关材料的参数，探讨高温干湿交替环境下，，这些参数的变化对界面劣化的影响。研究结果表明：300次循环后CFRP-混凝土界面承载力下降了9%，而GFRP-混凝土的承载力最大下降量达23%。高温干湿环境下，界面的粘结性能的劣化主要受树脂的劣化影响，选用CFRP粘结混凝土的耐久性比GFRP粘结混凝土的耐久性好，在该环境下，可以忽略混凝土强度的变化对界面劣化的影响。
[Abstract]:The concrete strengthening technology of FRP has been paid more and more attention by more and more scholars and engineers. The concrete structure strengthened by FRP is generally outside. Under the action of corrosion environment, how to design the durability of these structures and how to design the durability of FRP strengthened members? These problems restrict the development and popularization of FRP reinforced concrete technology. The durability of interface between FRP and resin and FRP and concrete is analyzed systematically. The main contents of this paper are as follows:. The study of durability of materials is the basis of the study of interfacial durability. In this paper, mechanical and microscopic experiments are used to study the effects of high temperature, dry and wet alternate environments on carbon fibers. The tensile properties of glass fiber and resin and the influence of compressive strength of concrete. The results show that the tensile strength of carbon fiber does not decrease and the elongation at break decreases slightly under the action of 300 high temperature dry and wet cycles. The tensile strength and elongation at break of glass fiber decreased more, and the elastic modulus of the two kinds of FRP remained unchanged, both macroscopic and microscopic experimental results showed that the delayed curing effect of resin had great influence on the mechanical properties of the resin in the early dry-wet cycle. The compressive strength of concrete has not decreased. The good bonding property between FRP and resin is one of the prerequisites to ensure that FRP can effectively strengthen concrete structures. In this paper, the shear tests and microscopic tests of 60 FRP lap specimens under different high temperature dry and wet cycles are carried out. It was found that the interfacial adhesion between FRP and resin was influenced little by the dry and wet environment for a short time, and the interfacial durability of FRP and resin could be improved by using FRP with rougher surface and larger gap between fiber and resin. The whole performance of concrete strengthened with FRP is directly affected by the bond behavior between FRP and concrete interface. In this paper, the deterioration of the interface of 60 FRP bonded concrete single shear specimens under different high temperature dry and wet environments is studied. Combined with the existing interfacial bond strength model, the parameters of the related materials that affect the interfacial bond strength are found, and the high temperature dry and wet alternating environment is discussed. The effect of these parameters on interface deterioration. The results show that the bearing capacity of CFRP- concrete decreases by 9% after 300 cycles, while the maximum capacity of GFRP- concrete decreases by 23%. The deterioration of the bond property of the interface is mainly affected by the deterioration of the resin. The durability of CFRP bonded concrete is better than that of GFRP bonded concrete. In this environment, the influence of the change of concrete strength on the interface deterioration can be ignored.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU37

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