混杂纤维高强混凝土基本力学性能和耐久性试验研究

发布时间：2018-03-30 21:33

本文选题：混杂纤维　切入点：高强混凝土　出处：《辽宁工业大学》2014年硕士论文

【摘要】：混凝土至今仍是全世界用量最大、应用最广泛的建筑材料，但其存在抗拉强度低、脆性大和易开裂的缺点。在混凝土中掺加纤维有助于克服混凝土材料的先天缺陷。同研究相对成熟的单掺纤维混凝土相比，采用不同品质、不同几何形态纤维混掺而成的混杂纤维混凝土，可以从不同层次上改善纤维三维分布的均衡性以及集料与纤维的协调作用，提高增强效率。本文通过正交试验设计对C60高强混凝土的配合比进行优化研究，检验拌合物的工作性能和28d强度，得出最优配合比；运用极差和方差分析量化了各因素对力学性能的影响水平。在最佳配合比下掺入不同掺量的聚丙烯纤维和钢纤维，配制出混杂纤维高强混凝土，并对基本力学性能和耐久性能进行试验研究，分析了混杂纤维对C60高强混凝土的增强增韧效果和对抗冻性、抗海水侵蚀性的影响。主要的研究如下：（1）研究了不掺纤维、单掺纤维、混杂纤维以及不同纤维掺入量对C60高强混凝土基本力学性能（立方体抗压性能、轴心抗压性能、劈拉性能和抗折性能）和耐久性（抗冻性能和抗海水侵蚀性能）的影响。（2）定义了评价混杂纤维混凝土混杂效应的指标—混杂系数的计算公式，利用混杂系数系统地分析和对比了不同情况下纤维对C60高强混凝土基本力学性能和耐久性能的影响。研究分析的结果显示：（1）单掺钢纤维时高强混凝土的抗压强度、轴心抗压强度、劈拉强度和抗折强度都有一定程度的提高。单掺聚丙烯纤维使抗压强度和轴心抗压强度略有下降的影响，而对劈拉强度和抗折强度都有很好的提高作用。当二者混掺时，高强混凝土的抗压强度、轴心抗压强度、劈拉强度和抗折强度都要比不掺纤维的混凝土高，但混杂效果取决于纤维掺量及比例；（2）对纤维混凝土和不掺纤维混凝土进行冻融循环试验和海水侵蚀试验，发现纤维混凝土的抗冻性能和耐腐蚀性能都明显优于不掺纤维混凝土。同时也发现，，混杂纤维的掺量和比例对高强混凝土抗冻性能和耐腐蚀性能有很大影响。
[Abstract]:The maximum amount of concrete is still the world, the most widely used building materials, but it has low tensile strength, brittle and easy to crack. The shortcomings of the fibers in the concrete mixing helps to overcome the defects of concrete materials. With the research on single doped fiber concrete is relatively mature compared with different quality, hybrid fiber reinforced concrete fiber mixed with different geometric shapes and coordination function can improve the balance of the three-dimensional distribution of fiber aggregates and fibers from different levels, and improve efficiency.
This paper through the orthogonal experimental design of C60 high strength concrete mix proportion optimization, test of mixture working performance and strength of 28d, the optimal mixing ratio; the use of range analysis and variance analysis to quantify the effect of each factor level. On the mechanical properties of polypropylene fiber and steel fiber in different dosage ratio of mixed in with the best. Preparation of hybrid fiber reinforced high-strength concrete, and the experimental study on basic mechanical properties and durability, the method of strengthening toughening effect and frost resistance of hybrid fibers on C60 high strength concrete, the influence of seawater erosion resistance. The main research are as follows:
(1) the effects of fiber content, single fiber, hybrid fiber and different fiber contents on the basic mechanical properties (cube compressive strength, axial compressive strength, splitting tensile and flexural properties) and durability (frost resistance and seawater erosion resistance) of C60 high strength concrete were studied.
(2) defined the index of hybrid fiber reinforced concrete, the calculation formula of the hybrid coefficient. The influence of fiber on the basic mechanical properties and durability of C60 high strength concrete under different conditions is systematically analyzed and compared by using the hybrid coefficient.
The results of the research and analysis show that:
(1) single steel fiber high strength concrete compressive strength, axial compressive strength, splitting tensile strength and flexural strength were improved. Influence of PP fiber on the compressive strength and compressive strength decreased slightly, and has a very good role in improving the splitting tensile strength and flexural strength two. When mixing, concrete compressive strength, axial compressive strength, splitting tensile strength and flexural strength are lower than those without fiber concrete is high, but the confounding effect depends on the fiber content and proportion;
(2) of fiber concrete and fiber reinforced concrete subjected to freeze-thaw cycle test and erosion test, found that the frost resistance of fiber reinforced concrete and corrosion resistance are better than no fiber concrete. It is also found that the content and proportion of hybrid fiber on the frost resistance of high strength concrete and corrosion resistance are greatly affected.

【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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