荷载与环境作用下钢筋混凝土锈蚀粘结力及锈胀开裂研究

发布时间：2018-02-21 09:25

本文关键词： 钢筋混凝土结构电化学加速锈蚀方法非均匀锈蚀粘结强度临界锈蚀深度开裂模式锈蚀产物分布　出处：《浙江大学》2013年硕士论文　论文类型：学位论文

【摘要】：氯盐侵蚀是导致钢筋混凝土结构服役性能劣化的重要原因。考虑不同环境与荷载耦合作用对钢筋混凝土锈胀开裂的重要影响,对准确预测钢筋混凝土结构的服役寿命也具有十分重要的意义。该文以此为主线,重点研究了混凝土保护层锈胀开裂发展过程。主要研究工作如下： (1)采用外加电流加速锈蚀方法可以快速的模拟混凝土中钢筋的锈蚀过程,但是不同锈蚀方法得到的结论存在很大区别。该文采用四种不同的外加电流加速锈蚀方法对荷载作用下混凝土中钢筋的锈蚀过程进行了模拟,并分析了锈蚀后钢筋表面形态特征及锈蚀产物的形貌和成分。 (2)根据钢筋的非均匀锈蚀特征,对锈蚀带肋钢筋与混凝土间的粘结性能进行了研究。基于未锈蚀带肋钢筋粘结强度的微观受力模型与均匀锈蚀带肋钢筋粘结性能模型,考虑钢筋实际锈蚀为非均匀锈蚀,利用弹性力学方法建立了带肋钢筋粘结强度预测模型,推导出锈蚀带肋钢筋与混凝土间的极限粘结强度,对有无横向约束的锈蚀钢筋极限粘结强度进行了分析,并且对混凝土开裂时刻钢筋的临界锈蚀深度进行了预测。 (3)为提高混凝土结构的服役性能,对混凝土保护层的锈胀开裂过程进行了研究。通过对荷载作用下锈蚀18个月的内掺氯盐钢筋混凝土梁的截面锈胀裂缝分析,考虑钢筋混凝土受力状态及骨料与裂缝的相对位置,对锈胀裂缝开裂模式及锈蚀产物分布情况进行了研究。同时对混凝土保护层的破坏形式进行了分析,提出锈蚀钢筋混凝土梁设计建议,对钢筋混凝土结构的服役性能评估和修复具有重要意义论文得到国家高技术研究发展计划(863计划)(2012AA050903),国家自然科学基金(51178413、51008272和50838008)与国家重点基础研究发展计划(973计划)(2009CB623200)的资助。
[Abstract]:Chloride erosion is an important cause of deterioration of service performance of reinforced concrete structures. It is also of great significance to accurately predict the service life of reinforced concrete structures. This paper focuses on the development process of rust expansion cracking of concrete cover. The main research work is as follows:. 1) the corrosion process of steel bars in concrete can be quickly simulated by applying applied electric current to accelerate corrosion. However, the conclusions obtained by different corrosion methods are very different. In this paper, the corrosion process of steel bars in concrete under load is simulated by four different applied electric current accelerated corrosion methods. The surface morphology, morphology and composition of corroded steel bar were analyzed. 2) according to the inhomogeneous corrosion characteristics of steel bar, the bond behavior between corroded ribbed steel bar and concrete is studied. Based on the model of bond strength of non-corroded ribbed steel bar and uniform corroded ribbed steel bar, the bond behavior model of corroded ribbed steel bar is presented. Considering that the actual corrosion of steel bar is non-uniform corrosion, a prediction model of bond strength of ribbed steel bar is established by means of elastic mechanics method, and the ultimate bond strength between corroded ribbed steel bar and concrete is deduced. The ultimate bond strength of corroded steel bar with or without transverse constraints is analyzed and the critical corrosion depth of steel bar at cracking time is predicted. In order to improve the service performance of concrete structure, the process of corrosion expansion cracking of concrete cover is studied. Considering the stress state of reinforced concrete and the relative position of aggregate and crack, the cracking mode and the distribution of corrosion products are studied. It is of great significance to evaluate and repair the service performance of reinforced concrete structures by putting forward some suggestions for the design of corroded reinforced concrete beams. The paper is supported by the National High Technology Research and Development Program, the National High Technology Research and Development Program No. 2012AA050903, the National Natural Science Foundation of China, 51178413, 51008272 and 50838008, and the State key basic Research and Development Program, the State key basic Research and Development Program, 2009 CB623200).
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375;TU312

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