混杂聚丙烯纤维混凝土损伤力学性能研究

发布时间：2018-01-12 11:04

本文关键词：混杂聚丙烯纤维混凝土损伤力学性能研究　出处：《重庆大学》2013年硕士论文　论文类型：学位论文

【摘要】：纤维混凝土是近年来发展非常迅速的新型复合建筑材料，广泛运用于土木、建筑、交通、水利等领域。在混凝土中掺加纤维能从材料成分上改善混凝土固有的缺陷，有效改善混凝土的抗裂性、韧性、抗渗透性，提高混凝土的强度、耐久性、耐磨性等性能。而混杂纤维混凝土是纤维混凝土发展的新方向，它能够在不同的结构层次和荷载等级上逐级阻裂和性能互补，相比单一纤维的改善增强效果更好，但目前有关混杂纤维混凝土的研究还比较少。本文采用理论分析、室内试验和数值模拟等方法，对混杂及单一聚丙烯纤维混凝土的损伤力学性能等进行较为系统深入的研究，主要研究工作和成果如下： ①进行了混杂聚丙烯纤维混凝土轴心抗压及抗拉试验，，研究混杂聚丙烯纤维和单一聚丙烯纤维对混凝土强度和韧性的改善效果。结果表明，对于混凝土的抗压性能和弹性模量，单一掺加聚丙烯纤维大部分能够适当增强；对于混凝土的抗拉性能，单一掺加聚丙烯纤维能有一定程度的增强。而掺加混杂聚丙烯纤维都能增强混凝土的抗压和抗拉性能，且增强效果明显比单一纤维好。在抗压曲线和抗拉曲线的走势上，掺加聚丙烯纤维的曲线延性更好，且混杂聚丙烯纤维的延性明显更好于单一纤维。说明了混杂聚丙烯纤维对混凝土的强度和韧性的改善效果明显优于单一聚丙烯纤维。 ②采用有限元分析软件ABAQUS结合纤维混凝土损伤本构模型对相同条件下的室内试验模型进行数值模拟，对比分析数值模拟结果和试验成果，验证了数值模拟的正确性。同时得到了本试验的聚丙烯纤维混凝土损伤本构模型中损伤因子的曲线形状参数的变化规律以及混凝土压缩、拉伸损伤因子随应变的发展规律。 ③利用ABAQUS有限元软件分析不同混凝土强度等级下的纤维混凝土损伤特性，结果表明，在一定的混凝土强度等级范围内，混凝土累积损伤随着混凝土强度等级的降低而增大，但不同混凝土强度等级之间的累积损伤相差很小。
[Abstract]:Fiber reinforced concrete (FRC) is a new type of composite building material which has been developed rapidly in recent years. It is widely used in civil engineering, construction and transportation. Water conservancy and other fields. Adding fiber in concrete can improve the inherent defects of concrete from the material composition, effectively improve the crack resistance, toughness, permeability resistance of concrete, improve the strength and durability of concrete. Hybrid fiber reinforced concrete is a new development direction of fiber reinforced concrete. It can resist crack and complement each other step by step in different structure level and load grade. Compared with the single fiber, the improvement and reinforcement effect is better, but the research on hybrid fiber concrete is still relatively few. In this paper, theoretical analysis, laboratory test and numerical simulation methods are used. The damage mechanical properties of hybrid and single polypropylene fiber reinforced concrete are studied systematically and deeply. The main work and results are as follows: 1. The axial compressive and tensile tests of hybrid polypropylene fiber concrete were carried out, and the improvement effect of hybrid polypropylene fiber and single polypropylene fiber on the strength and toughness of concrete was studied. For the compressive properties and elastic modulus of concrete, most of the concrete can be strengthened by adding polypropylene fiber. The tensile properties of concrete can be enhanced by adding polypropylene fiber to a certain extent, but the compressive and tensile properties of concrete can be enhanced by adding hybrid polypropylene fiber. And the reinforcing effect is obviously better than that of single fiber. The curve ductility of polypropylene fiber mixed with polypropylene fiber is better than that of single fiber in the trend of compression curve and tensile curve. The ductility of hybrid polypropylene fiber is better than that of single fiber, which indicates that hybrid polypropylene fiber can improve the strength and toughness of concrete obviously better than that of single polypropylene fiber. 2 using the finite element analysis software ABAQUS and the damage constitutive model of fiber reinforced concrete to simulate the indoor test model under the same conditions, the numerical simulation results and the experimental results are compared and analyzed. The correctness of the numerical simulation is verified and the curve shape parameters of the damage factor in the damage constitutive model of polypropylene fiber reinforced concrete in this experiment are obtained as well as the compression of concrete. The development of tensile damage factor with strain. 3 using ABAQUS finite element software to analyze the damage characteristics of fiber reinforced concrete under different concrete strength grades. The results show that the damage characteristics of fiber reinforced concrete are within a certain range of concrete strength grade. The cumulative damage of concrete increases with the decrease of concrete strength grade, but the difference of cumulative damage between different concrete strength grades is very small.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528.572

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