硫酸盐侵蚀条件下混凝土耐久性指标分析研究

发布时间：2018-01-04 21:44

本文关键词：硫酸盐侵蚀条件下混凝土耐久性指标分析研究　出处：《郑州大学》2015年硕士论文　论文类型：学位论文

更多相关文章： 混凝土 耐久性 力学性能 硫酸盐

【摘要】：钢筋混凝土结构的耐久性问题是工程实践中经常遇到的问题,各国研究人员针对地上混凝土混凝土结构耐久性的研究比较深入。由于我国疆域辽阔,近年来随着大量基础设施的建设及投入使用,工程结构所面临的耐久性问题也复杂多样。当混凝土结构处于硫酸盐作用下的环境时,混凝土结构的力学及耐久性能受到削弱,这严重危害结构的安全使用。因此,开展硫酸盐作用下混凝土的实验研究,具有重要的经济及社会价值。本文所开展的主要工作:1、阐明了混凝土结构耐久性研究的重要意义,同时介绍了本文的研究依据及研究背景。通过混凝土内部因素、外部因素、内部因素与外部因素耦合作用等三个方面阐述了硫酸盐侵蚀条件下混凝土结构耐久性研究概况,同时阐述了基础结构混凝土耐久性研究的现状,并指出了目前研究中还存在的问题。2、针对工程中常用的C30及C40混凝土,以混凝土水胶比、硫酸盐溶液浓度及浸泡龄期为主要影响因素,开展室内试验研究,并开展了混凝土立方体抗压强度、混凝土劈裂、混凝土静力受压弹性模量、混凝土轴心抗压强度、混凝土质量、混凝土动弹性模量、混凝土电阻率及混凝土氯离子扩散系数等指标的测定。3、依据试验结果,分析了相同环境条件下混凝土原材料对混凝土物理力学性能的影响。分析表明:水胶比对混凝土物理力学及耐久性能影响较大。4、依据试验结果,分析了硫酸盐溶液浓度对混凝土物理力学及耐久性能的影响。分析表明:在硫酸盐浓度为0mg/L~15000mg/L范围内混凝土劈裂强度、电阻率、混凝土氯离子渗透系数及质量的变化幅度随着硫酸根离子浓度的上升呈现先变大后变小的趋势。5、依据试验结果,研究了混凝土物理力学及耐久性能随试验龄期的变化规律。分析表明:混凝土电阻率、劈裂抗拉强度、质量及氯离子扩散系数随试验龄期的变化比较敏感。
[Abstract]:The durability of reinforced concrete structures is a common problem in engineering practice. The research on the durability of concrete structures above ground by researchers from all over the world is more in-depth. Because of the vast territory of our country. In recent years, with the construction of a large number of infrastructure and put into use, the durability of engineering structures is also complex and diverse, when the concrete structure is in the sulphate environment. The mechanical and durability of concrete structure is weakened, which seriously endangers the safe use of the structure. Therefore, the experimental study of concrete under the action of sulfate is carried out. It has important economic and social value. The main work of this paper: 1, illustrates the importance of the durability study of concrete structures. At the same time, this paper introduces the research basis and background, through the internal factors of concrete, external factors. In this paper, the research situation of durability of concrete structure under sulfate erosion and the present situation of durability research of foundation structure concrete are expounded in three aspects, such as coupling effect of internal factor and external factor, and so on. At the same time, it points out the existing problems in the present research. Aiming at C30 and C40 concrete commonly used in engineering, the main influencing factors are concrete water-binder ratio, sulfate solution concentration and immersion age. In this paper, the concrete cube compressive strength, concrete splitting, static compressive elastic modulus of concrete, axial compressive strength of concrete, concrete quality and dynamic elastic modulus of concrete are carried out. The resistivity of concrete and the chloride diffusion coefficient of concrete are measured. 3, according to the test results. The effects of raw materials of concrete on the physical and mechanical properties of concrete under the same environment are analyzed. The analysis shows that the ratio of water to binder has a great influence on the physical mechanics and durability of concrete. The effect of sulfate concentration on the physical mechanics and durability of concrete is analyzed. The results show that the splitting strength and resistivity of concrete are within the range of 0 mg / L ~ (15 000) mg / L sulfate concentration. The change range of chloride ion permeability coefficient and mass of concrete with the increase of sulfate ion concentration showed a trend of increasing first and then becoming smaller. 5. According to the test results. The variation of physical mechanics and durability energy of concrete with test age is studied. The results show that concrete resistivity, splitting tensile strength, mass and chloride diffusion coefficient are sensitive to the test age.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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