FRP-钢复合筋拉伸力学性能、耐久性及其与混凝土粘结性能试验研究

发布时间：2018-03-26 11:17

本文选题：FRP-钢复合筋　切入点：应力-应变本构　出处：《深圳大学》2017年硕士论文

【摘要】：在现代工业和建筑业中,钢筋混凝土作为一种结构材料在工程应用中占有相当大的比重。当暴露于不利环境时(碳化、氯离子侵蚀、海洋环境等),混凝土中作为骨架的钢筋往往因为有害介质而发生腐蚀,从而使混凝土结构提前结束其使用寿命。近年来兴起的FRP筋虽然不易腐蚀,然而FRP是完全线弹性材料,延性不足,工程应用推广存在一定难度。为此,本文提出了结合两种材料优势的新型复合材料筋,即以钢筋为内芯,在其外部包裹纤维材料形成FRP-钢复合筋。本文参考纯FRP筋的加工流程,提出了FRP-钢复合筋(下文简称复合筋)的成型工艺,利用FRP筋的生产设备,完成了复合筋的工业化制备。通过试验手段,对复合筋的基本力学性能及耐久性能展开研究,主要包括以下工作:(1)针对不同类型复合筋展开拉伸力学试验,详细介绍了筋材的破坏形态,分析了筋材的屈服强度,极限强度,弹性模量及应力-应变曲线;基于材料复合法则,建立了复合筋的应力-应变本构模型,与试验获得数据对比,发现两者吻合较好。(2)通过加速锈蚀试验,得到不同设计锈蚀率的复合筋试件;利用环境扫描电镜(SEM)和能谱仪(EDS)技术对复合筋试件的锈蚀情况进行定性分析,判定有少量疑似铁锈的产物生成;结合不同类型筋材的锈层分布及纤维包覆层孔隙结构进行分析,发现纤维种类和孔隙结构对复合筋耐蚀性能影响显著。利用X射线微型计算机断层扫描(Micro-XCT)技术对锈蚀试件物质组分进行定量分析,发现复合筋的实际锈蚀率远远小于未包裹纤维层的光圆钢筋,CFRP-钢复合筋的实际锈蚀率不到钢筋的1/10,GFRP-钢复合筋的实际锈蚀率不到钢筋的1/100。据此可以认为复合筋具有良好的耐腐蚀性能。(3)在复合筋-混凝土粘结滑移试验的基础上,主要分析了纤维种类、筋材直径、表面处理方式等因素对复合筋-混凝土粘结试件的破坏形态,粘结强度及粘结-滑移曲线的影响。
[Abstract]:In modern industry and construction, reinforced concrete, as a structural material, accounts for a considerable proportion of engineering applications. In the marine environment and so on, the steel bars used as skeletons in concrete are often corroded because of harmful media, thus making concrete structures end their service life ahead of time. Although the FRP bars that have emerged in recent years are not easy to corrode, FRP is a completely linear elastic material. The ductility is not enough, so it is difficult to popularize the engineering application. Therefore, a new type of composite steel bar, which combines the advantages of two kinds of materials, is proposed in this paper, that is, the steel bar is used as the inner core. In this paper, the forming process of FRP- steel composite reinforcement (hereinafter referred to as composite reinforcement) is put forward with reference to the processing process of pure FRP steel bar, and the production equipment of FRP steel bar is used to make use of the forming process of FRP- steel composite reinforcement. The industrial preparation of composite tendons has been completed. The basic mechanical properties and durability of composite tendons have been studied by means of tests, including the following work: 1) tensile mechanical tests for different types of composite tendons. The failure mode of steel bar is introduced in detail, and the yield strength, ultimate strength, elastic modulus and stress-strain curve are analyzed, and the stress-strain constitutive model of composite reinforcement is established based on the composite rule of materials. Comparing with the experimental data, it is found that the two methods are in good agreement with each other. (2) by accelerating the corrosion test, the specimens with different design corrosion rates are obtained. Environmental scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) were used to qualitatively analyze the corrosion of composite steel specimens, to determine the formation of a small amount of suspected rust products, and to analyze the distribution of rust layer and the pore structure of fiber coated layer in different types of steel bars. It is found that the types of fibers and pore structure have a significant effect on the corrosion resistance of composite tendons. It is found that the actual corrosion rate of composite reinforcement is much lower than that of plain circular steel bar without fiber layer. The actual corrosion rate of CFRP- steel composite reinforcement is less than that of 1 / 10 GFRP- steel composite reinforcement, which is less than 1 / 100 of that of steel bar. It can be concluded that the composite steel bar has a corrosion rate of less than 1 / 100 of that of steel bar. Good corrosion resistance. 3) on the basis of the bond-slip test of composite tendon-concrete, The effects of fiber types, reinforcement diameter and surface treatment methods on the failure patterns, bond strength and bond-slip curves of composite reinforced concrete bonded specimens are analyzed.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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