修补混凝土抗氯离子渗透性能试验研究

发布时间：2018-03-10 21:15

本文选题：修补混凝土　切入点：耐久性　出处：《河北农业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国经济建设的迅速发展，建筑行业在经历大规模的建设期后，逐步开始转变为新建和维修的并重时期，对既有混凝土结构的修补加固逐渐成为建筑工程领域研究的一项重要内容，修补混凝土的各项性能参数得到了更多专家的重视。判定修补加固的混凝土是否合格，不仅要修补后混凝土的强度达到规定值，其耐久性能也是重要的衡量指标。一般来说，混凝土结构内部的钢筋锈蚀是引发结构耐久性失效的主因，而氯离子侵蚀则是诱发钢筋锈蚀的最主要因素。基于此，本文以混凝土抗氯离子侵蚀能力作为评判混凝土耐久性的重要指标，对各类修补后的混凝土进行氯离子渗透性能研究，探讨不同修补状态对修补混凝土强度、氯离子渗透性能的影响。本文依托于河北省建设集团安徽分公司，在其马鞍山市公安局业务技术用房改造工程项目中的对局部混凝土破损修补出现的若干耐久性问题的氯离子侵蚀部分，，进行相关的试验研究。试验通过对该工程中使用的两种强度等级的混凝土C30和C40，同时外加设计C50混凝土进行交叉修补，观测修补前后混凝土的抗压强度和抗氯离子渗透能力，通过实验数据的分析比较，研究修补状态对补后混凝土性能的影响。试验主要分为两部分，一部分采用100100100mm3的混凝土立方体试块，量测交叉修补前后抗压强度的变化；另一部分采用φ10050mm3的混凝土圆柱体试块，量测交叉修补前后抗氯离子渗透性能的变化；其中氯离子渗透试验采用混凝土耐久性标准测定方法——快速氯离子迁移系数试验方法。文中参照传统的氯离子渗入模型，结合修补试验结果，进行综合分析，建立针对于修补混凝土的修正氯离子渗入模型；结合修补混凝土抗压强度分析，提出“强渗比”概念，依此来评定最优交叉修补混凝土组合，为工程实际局部破损的修补提供参考。分析结果可以得出，在修补混凝土满足强度要求的条件下，若原破损混凝土为低强度级别（C30）时，宜采用略高强度级别的混凝土进行修补，且不宜采用相对强度等级差别较大的混凝土进行修补；若原破损混凝土为高强度级别（C40）时，建议采用修补混凝土的强度级别不宜与原破损混凝土相差太大。
[Abstract]:With the rapid development of China's economic construction, the construction industry has gradually begun to change into a period of equal importance between new construction and maintenance after experiencing a large-scale construction period. The mending and strengthening of existing concrete structures has gradually become an important content in the field of building engineering. The performance parameters of repaired concrete have been paid more attention by many experts. Not only should the strength of the repaired concrete reach the specified value, but also its durability is an important index. Generally speaking, the corrosion of steel bar inside the concrete structure is the main cause of the structural durability failure. Chloride ion erosion is the main factor that induces the corrosion of steel bars. Based on this, the chloride ion permeability of various repaired concrete is studied based on the chloride corrosion resistance of concrete as an important index to evaluate the durability of concrete. The effect of different repair states on strength and chloride ion permeability of repaired concrete was discussed. This paper is based on Anhui Branch of Hebei Construction Group, and in its project of technical and technical renovation of technical housing of Ma'anshan Public Security Bureau, the chloride erosion part of some durability problems occurred in partial concrete damage repair, Through two kinds of strength grade concrete C30 and C40 used in the project, and the design of C50 concrete for cross-repair, the compressive strength and chloride permeable ability of the concrete before and after the repair were observed. Through the analysis and comparison of experimental data, the effect of repair state on the performance of post-repair concrete is studied. The experiment is mainly divided into two parts, one part is using 100100mm3 concrete cube test block to measure the change of compressive strength before and after cross-repair. The other part uses 蠁 10050mm3 concrete cylinder to measure the change of chloride penetration resistance before and after cross-repair. The chloride ion permeation test is based on the test method of fast chloride ion transport coefficient, which is the standard test method for durability of concrete. According to the traditional chloride ion infiltration model and the result of repair test, the comprehensive analysis is carried out. A modified chloride infiltration model for repairing concrete is established, and the concept of "strong permeability ratio" is put forward according to the analysis of compressive strength of repaired concrete, according to which the optimal cross-repair concrete combination is evaluated. It provides a reference for repairing the actual local damage of engineering. The analysis results show that if the original damaged concrete is of low strength grade C30, if the repair concrete meets the strength requirement, it should be repaired with slightly higher strength grade concrete. If the original damaged concrete is high strength grade C40, the strength grade of repaired concrete should not be too different from that of original damaged concrete.
【学位授予单位】：河北农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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