C90高强高性能混凝土配合比设计及其力学性能试验研究

发布时间：2018-04-25 23:21

本文选题：C90高强高性能混凝土 + 试验室基准配合比　；参考：《重庆交通大学》2017年硕士论文

【摘要】：高强高性能混凝土与普通混凝土相比,在工作性、力学性、耐久性、经济性等方面有着一定的优势。采用高强高性能混凝土可以使结构物体积更小,这样既能满足更多特定形状下的承载力需要,又能合理利用资源、节约成本,因此,对高强高性能混凝土的研究具有重要意义。本文以C90高强高性能混凝土为研究对象,主要进行了原材料选择、配合比设计、工作性、力学性、耐久性、微观机理等六个方面的工作。首先对C90高强高性能混凝土用原材料进行优选,在初步计算配合比和试拌试验的基础上,通过正交试验方法选取粉煤灰、矿渣粉、硅灰三种矿物掺合料的最佳掺量,得到试验室基准配合比;其次,在试验室基准配合比下,通过对比试验研究了胶凝材料的总量、水胶比、砂率三个因素发生变化时对混凝土立方体抗压强度、棱柱体抗压强度、抗弯拉强度、劈裂抗拉强度、抗压弹性模量等的影响规律,其中胶凝材料总量分别为550kg/m~3、600 kg/m~3、650 kg/m~3,水胶比分别为0.20、0.22、0.24,砂率分别为38%、40%、42%。高强混凝土的强度等级是以立方体标准试件的抗压强度为判定依据,在研究五个力学性能变化规律时,试验提出标准试件和非标准试件之间的尺寸换算系数。本文所配置的C90高强高性能混凝土满足抗压强度要求,并且经试验提出了其他四个力学性能指标与抗压强度的回归曲线与方程,得到了五个力学指标之间的换算关系式。通过抗氯离子渗透试验、早期抗裂试验研究所配制的C90高强高性能混凝土的抗渗性能和抗开裂性能。抗氯离子试验采用电通量法测算C90高强高性能混凝土28d的电通量和抗渗系数,收缩试验采用接触法分别测得混凝土硬化后和3d标养后的长龄期收缩值,早期抗裂试验采用平板法研究C90高强高性能混凝土的抗裂性能。通过扫描电镜技术(SEM)和X-射线衍射技术(XRD)分析C90高强高性能混凝土与普通强度混凝土之间的形态特征和物相的差别,从微观方面分析了C90高强高性能混凝土性能优越的原因。
[Abstract]:Compared with ordinary concrete, high strength and high performance concrete has some advantages in working property, mechanical property, durability, economy and so on. Using high strength and high performance concrete can make the volume of structure smaller, which can not only meet the need of bearing capacity under more specific shape, but also make rational use of resources and save cost. Therefore, the study of high strength and high performance concrete is of great significance. In this paper, the C90 high strength and high performance concrete is taken as the research object. Six aspects of material selection, mix ratio design, workability, mechanics, durability and microscopic mechanism are carried out in this paper. At first, the raw materials for C90 high strength and high performance concrete are selected. On the basis of preliminary calculation of mix ratio and trial mixing test, the optimum amount of three mineral admixtures of fly ash, slag powder and silica fume is selected by orthogonal test method. Secondly, under the laboratory reference mix ratio, the compressive strength of concrete cube and the compressive strength of prism are studied when the total amount of cementing material, the ratio of water to binder and the ratio of sand to sand change. The effects of bending and tensile strength, splitting tensile strength and compressive elastic modulus are studied. The total amount of cementitious material is 3 550kg/m~3600 kg/m~3650 / kg / m ~ (3), the ratio of water to binder is 0.20 ~ 0.22 ~ 0.24, and the sand ratio is 38 ~ 40 ~ 40 ~ 42% respectively. The strength grade of high strength concrete is based on the compressive strength of cubic standard specimens. In the study of five laws of mechanical properties, the size conversion coefficient between standard and non-standard specimens is proposed. The C90 high strength and high performance concrete in this paper meets the requirements of compressive strength, and the regression curves and equations of the other four mechanical performance indexes and compressive strength are put forward through experiments, and the conversion relations between the five mechanical indexes are obtained. The impermeability and cracking resistance of C90 high strength and high performance concrete prepared by early crack resistance test and chloride ion permeation test were studied. The electric flux and impermeability coefficient of C90 high strength and high performance concrete were measured by the electric flux method in the chloride ion resistance test. The shrinkage test was used to measure the long age shrinkage of the concrete after hardening and 3 d standard maintenance, respectively. The crack resistance of C 90 high strength and high performance concrete was studied by plate method in early crack resistance test. The morphological characteristics and phase differences between C90 high strength and high performance concrete and ordinary strength concrete were analyzed by means of scanning electron microscopy (SEM) and X ray diffraction (XRD). The reasons for the superior performance of C90 high strength and high performance concrete were analyzed from the microcosmic point of view.
【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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