基于全计算法配制C90自密实混凝土性能研究

发布时间：2018-04-29 14:07

本文选题：C90高强自密实混凝土 + 工作性能　；参考：《重庆交通大学》2017年硕士论文

【摘要】：高强自密实混凝土是随着现代建筑大跨度结构、高层和超高层的需求应运而生的一种高性能混凝土。它通过掺入活性矿物掺和料和高性能减水剂,使高强混凝土的流动性得到提高,同时不出现离析和泌水现象,具有较好的黏聚性,限制骨料下沉,使其成为均匀、密实、稳定的混凝土拌合物。高强自密实混凝土除了具有高强混凝土能够承受大跨、超高、重载的特点,还可以填充薄壁、狭窄空间,减小建筑构件的截面面积,增加配筋率,进而提高构件的抗弯性能,在提高抗压强度的同时,使结构更加安全稳定,高强自密实混凝土的研究对现代混凝土发展具有重要意义。本文首先对C90高强自密实混凝土的原材料进行测试,选择满足规范要求的原材料;采用正交试验设计对粉煤灰、矿渣粉和硅灰的组合进行混凝土试验,优选出活性矿物掺合料的最佳掺入比例为粉煤灰10%、矿渣粉10%、硅灰6%;采用全计算法结合绝对体积法进行基准配合比设计,配制出的高性能混凝土满足C90高强自密实混凝土的工作性、抗压强度及耐久性要求;在此基础上,研究了粗集料级配和粒形、细集料级配和砂率、胶凝材料总量、外加剂掺量、水胶比对C90高强自密实混凝土工作性能和力学性能的影响。对配制出的C90高强自密实混凝土进行收缩试验、早期开裂试验和抗氯离子渗透试验,试验结果表明其变形性能及抗氯离子渗透性能良好,达到较高等级。最后利用SEM图片对C90高强自密实混凝土进行微观结构观察和机理分析,为优异的宏观性能作出科学解释。
[Abstract]:High strength self-compacting concrete (HSC) is a kind of high performance concrete (HPC) which comes into being with the needs of high-rise and super high-rise buildings with the development of large span structures of modern buildings. It can improve the fluidity of high strength concrete by adding active mineral admixture and high performance water reducing agent, and at the same time, it does not appear the phenomenon of segregation and bleeding. It has better cohesion, limits aggregate sinking, and makes it uniform and dense. A stable mix of concrete. High strength self-compacting concrete not only has the characteristics of high strength concrete can withstand long span, super high, heavy load, but also can fill thin-walled, narrow space, reduce the cross-section area of building members, increase the reinforcement ratio, and then improve the flexural performance of the members. The research of high strength self-compacting concrete is of great significance to the development of modern concrete. In this paper, the raw materials of C90 high strength self-compacting concrete are tested firstly, and the raw materials that meet the requirements of the specification are selected, and the combination of fly ash, slag powder and silica fume is tested by orthogonal test design. The optimum mixing ratio of active mineral admixture is fly ash 10, slag powder 10 and silica fume 6. The whole calculation method combined with absolute volume method is used to design the standard mix ratio. The prepared high performance concrete can meet the requirements of C90 high strength self-compacting concrete, such as workability, compressive strength and durability. On the basis of this, the coarse aggregate gradation and grain shape, fine aggregate gradation and sand ratio, total amount of cementing material, admixture amount are studied. The effect of water / binder ratio on the working and mechanical properties of C 90 high strength self compacting concrete. The shrinkage test, early cracking test and chloride ion permeation resistance test of C90 high strength self-compacting concrete are carried out. The results show that the deformation property and chloride permeation resistance of C90 high strength self-compacting concrete are good and reach a higher grade. Finally, the microstructure observation and mechanism analysis of C90 high strength self-compacting concrete are carried out by using SEM pictures, which can explain the excellent macroscopic properties scientifically.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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