金属材料锈蚀的一种新型辨识方法研究

发布时间：2018-04-09 20:18

本文选题：滨海混凝土结构　切入点：金属材料锈蚀　出处：《深圳大学》2017年硕士论文

【摘要】：氯离子引起钢筋锈蚀通常被认为是滨海钢筋混凝土结构性能劣化的主要原因,而钢筋锈蚀则因其表面集聚的氯离子浓度达到阈值进而破坏钢筋表层的钝化膜所致。电化学方法是判别钢筋起锈和锈蚀速率的常规方法,但该方法测试手段间接,测试结果离散性大。据此,本文基于一种辨识钢筋等金属材料锈蚀的新型装置及原理,探讨利用该装置进行测试的技术问题和可选方案,为进一步开展钢筋等金属材料锈蚀的系列研究,寻求建立新型辨识准则和测试规程提供理论和技术支撑。主要研究工作和成果如下。1.简要介绍了所述钢筋等金属材料锈蚀的新型辨识装置的基本构造和原理,它由施力件、受力钢丝及两者的连接部组合而成。其中,施力件弯曲成弓型而对钢丝施加不同水平的预定应力,钢丝用于模拟实际结构中的受力钢筋,通过钢丝的蚀断提示钢筋锈蚀并辨识其锈蚀速率。鉴于整个装置弓型外形,以下简称其为“弓型装置”。2.探讨了利用弓型装置进行金属材料锈蚀辨识试验的技术可行性:真空环境中对装置进行长期静置观测,排除了常规应力下弓型装置钢丝由于应力疲劳而断裂的可能性;对腐蚀环境下钢丝断口的显微观测,则确定了钢丝断裂由腐蚀损伤所致的结论。3.分别采用试推和理论方法建立弓型装置重要力学参数——钢丝应力的简便计算方法并互证了计算结果的有效性;进而提出了制作目标应力弓型装置的方法并形成了相应专利初稿,由此提高了利用弓型装置开展应力腐蚀系列研究的效率和精度。4.考虑施力件材料特征、钢丝及连接部封装形式等因素,进行了弓型装置设计方案有效性的试验比较,从中优选出了测试结果稳定、离散性小的测试方案,较好解决了利用弓型装置开展钢筋等金属材料锈蚀试验研究的关键技术问题。5.利用弓型装置的合理试验方案,试验研究了钢丝锈蚀锈断时间、锈蚀速率的变化规律和分布特征,探讨了应力水平对钢丝锈蚀的影响。
[Abstract]:The corrosion of steel bars caused by chloride ions is generally considered to be the main cause of deterioration of the performance of coastal reinforced concrete structures, while the corrosion of steel bars is caused by the concentration of chloride ions on the surface reaches the threshold and then destroys the passivation film of the reinforcement surface.Electrochemical method is a conventional method for judging the rusting and rusting rate of steel bars, but the method is indirect and the test results are widely dispersed.On the basis of this, based on a new device and principle for identifying corrosion of steel bars and other metal materials, this paper discusses the technical problems and optional schemes of testing with this device, in order to further carry out a series of researches on corrosion of metal materials such as steel bars.Seek to establish new identification criteria and test procedures to provide theoretical and technical support.The main research work and results are as follows.This paper briefly introduces the basic structure and principle of the new identification device for corrosion of the steel bars and other metal materials. It is composed of the applied parts, the stressed steel wires and the connecting parts of the two parts.The steel wire is used to simulate the stress of the steel bar in the actual structure. The corrosion of the steel bar is indicated by the erosion of the steel wire and the corrosion rate of the steel bar is identified.In view of the whole device bow shape, hereinafter referred to as "bow device". 2.The technical feasibility of corrosion identification test of metal material using bow device is discussed. The device is observed in vacuum environment for a long time and the possibility of steel wire fracture due to stress fatigue is excluded under conventional stress.According to the microscopic observation of steel wire fracture in corrosive environment, the conclusion that steel wire fracture is caused by corrosion damage is determined.A simple calculation method of steel wire stress, which is an important mechanical parameter of arch device, is established by means of trial and theoretical methods, and the validity of the calculation results is verified.Furthermore, the method of making the target stress bow device is put forward and the corresponding patent draft is formed, which improves the efficiency and precision of using the bow device to carry out the research on stress corrosion.Taking into account the material characteristics of the load-acting parts, the encapsulation form of the steel wire and the connection part, the experimental comparison of the effectiveness of the design scheme of the bow device is carried out, and the test scheme with stable test results and small dispersion is selected.The key technical problem of corrosion test of steel bar and other metal materials is solved.Based on the reasonable test scheme of the arch apparatus, the variation and distribution characteristics of rust breaking time and corrosion rate of steel wire were studied, and the influence of stress level on the corrosion of steel wire was discussed.
【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】：TU511.32

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