海洋环境下混凝土中钢筋锈蚀试验及耐久性计算方法

发布时间：2018-05-17 05:38

本文选题：海洋环境 + 氯离子扩散　；参考：《天津大学》2014年硕士论文

【摘要】：钢筋混凝土结构广泛应用于沿海工程中，海洋环境下钢筋混凝土结构的耐久性问题成为沿海工程结构设计与维护中面临的一个十分严重的问题。综合国内外统计资料发现，海洋环境下钢筋混凝土结构的耐久性破坏主要是由于氯离子侵蚀导致的钢筋锈蚀引起的。目前针对氯离子侵蚀的研究，大多没有考虑荷载的影响；对于混凝土内钢筋锈蚀的研究也多为定性研究，且现有的钢筋锈蚀速率模型差异较大。本文在前人研究成果的基础上，通过海洋环境下受荷混凝土中氯离子扩散试验和室内环境下内掺不同含量的氯盐加速钢筋锈蚀试验，分别得到了考虑荷载影响的氯离子侵蚀模型和室内加速条件下钢筋锈蚀模型。初步建立了室内加速环境试验与实际自然环境之间的时间相关关系，，从而将试验所得模型应用到结构耐久性分析系统中，并通过算例对高桩码头进行了耐久性寿命评估与预测。主要研究内容如下：（1）通过室内模拟海洋环境下盐雾区和潮汐区受荷混凝土中氯离子扩散试验，分析了表面氯离子浓度如何取值，荷载对氯离子扩散系数的影响，分别得到了盐雾环境和潮汐环境下考虑荷载修正系数的氯离子扩散模型；（2）通过室内环境下内掺不同含量的氯盐加速钢筋锈蚀试验，研究钢筋锈蚀速率的时变过程和钢筋锈蚀速率与氯离子含量关系，拟合出室内加速条件下钢筋锈蚀速率模型，并进行了验证；（3）依据多重环境时间相似理论，初步建立混凝土结构的耐久性室内加速环境与实际自然环境之间的时间相关关系；（4）基于JC法计算海洋环境下钢筋混凝土结构可靠度，通过算例对高桩码头面板、横梁和桩的正常使用极限状态进行结构可靠度分析，耐久性寿命评估与预测。
[Abstract]:Reinforced concrete structures are widely used in coastal engineering. The durability of reinforced concrete structures in marine environment has become a very serious problem in the design and maintenance of coastal engineering structures. It is found that the durability damage of reinforced concrete structures under marine environment is mainly caused by corrosion of steel bars caused by chloride ion erosion. At present, most of the researches on chloride corrosion do not consider the effect of load, and the researches on corrosion of steel bars in concrete are mostly qualitative, and the existing models of corrosion rate of steel bars differ greatly. In this paper, based on the previous research results, the chloride ion diffusion test in loaded concrete under marine environment and the accelerated corrosion test of steel bar with different contents of chlorine salt in indoor environment are carried out. The chloride erosion model considering the load and the reinforcing bar corrosion model under indoor accelerated condition were obtained respectively. The temporal correlation between indoor accelerated environmental test and actual natural environment is established, and the model is applied to the durability analysis system of structure, and the durability life of high pile wharf is evaluated and forecasted by an example. The main contents of the study are as follows: 1) through indoor simulation of chloride ion diffusion test in salt fog zone and tidal zone of loaded concrete in marine environment, the value of surface chlorine ion concentration and the influence of load on chloride ion diffusion coefficient are analyzed. The chloride diffusion model considering load correction coefficient in salt fog environment and tidal environment is obtained respectively. (2) through the accelerated corrosion test of reinforcing bars with different chlorine salts in indoor environment, the time-varying process of corrosion rate and the relationship between corrosion rate and chloride ion content are studied, and the model of corrosion rate of steel bars under indoor accelerated conditions is fitted. And verified; (3) based on the time similarity theory of multiple environments, the temporal correlation between the indoor accelerated environment and the natural environment of concrete structure is preliminarily established. 4) based on JC method, the reliability of reinforced concrete structures in marine environment is calculated. The structural reliability analysis, durability life evaluation and prediction of the normal service limit state of high pile wharf face slab, beam and pile are carried out through an example.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV332

【参考文献】