高延性纤维混凝土受压力学性能试验研究

发布时间：2018-11-14 14:34

【摘要】：高延性纤维混凝土(ECC)具有高强度、高延性和高能量吸收等特点，将其应用于混凝土结构中的连梁、承重柱底、梁柱节点和剪力墙塑性铰区等关键部位，可以显著提高结构的延性和耐损伤能力，增强其抗震和抗裂性能，因此，具有广泛的应用前景。为了便于高延性纤维混凝土的进一步研究和推广，有关材料基本力学性能的研究不可缺少，其中受压力学性能作为材料最基本的力学性能之一，具有重要的研究意义。同时，高延性纤维混凝土组分中不含有粗骨料，界面特性明显不同于普通混凝土，基体内又均匀分布有大量的PVA纤维，造成其受压力学性能明显区别于普通混凝土。因此，有关高延性纤维混凝土受压力学性能的研究十分必要。本文在课题组前期研究的基础上，采用单因素对比试验，拟对高延性纤维混凝土的抗压强度、抗折强度、强度关系、尺寸效应和受压本构模型进行研究，其主要内容如下： (1)基于课题组的前期研究成果，研究高延性纤维混凝土的受压破坏过程、裂缝形态和受压破坏机理以及抗折破坏过程，并研究纤维掺量、粉煤灰掺量、水胶比和砂胶比四种因子以及环境因素对高延性纤维混凝土各抗压性能指标和抗折强度的影响趋势，以便为高延性纤维混凝土的构件设计与工程应用提供一定的理论依据。 (2)基于课题组的前期研究成果，研究高延性纤维混凝土立方体抗压强度和轴心抗压强度之间的换算关系以及不同尺寸间的强度折算关系，即确定高延性纤维混凝土轴心抗压强度与立方体抗压强度的强度比值系数和尺寸效应系数。 (3)基于课题组的前期研究成果，对棱柱体试块进行单轴受压，，测定其受压应力-应变全曲线，并分析纤维掺量、水胶比、粉煤灰掺量和砂胶比对受压全曲线及曲线上各特征参数的影响，然后在此基础上提出相应的受压本构模型，为高延性纤维混凝土的结构设计和非线性数值模拟分析提供一定的理论依据。
[Abstract]:High ductile fiber reinforced concrete (ECC) has the characteristics of high strength, high ductility and high energy absorption. It is applied to the key parts of concrete structure, such as connecting beam, bearing column bottom, Liang Zhu joint and plastic hinge area of shear wall, etc. It can significantly improve the ductility and damage resistance of the structure, and enhance its seismic and crack resistance, so it has a wide application prospect. In order to facilitate the further research and popularization of high ductility fiber reinforced concrete, it is necessary to study the basic mechanical properties of materials, among which the compressive mechanical properties, as one of the most basic mechanical properties of materials, are of great significance. At the same time, there is no coarse aggregate in the composition of high ductile fiber concrete, and the interface characteristic is obviously different from that of ordinary concrete, and a large number of PVA fibers are distributed uniformly in the foundation, which makes the compressive mechanical properties of high ductile fiber concrete obviously different from that of ordinary concrete. Therefore, it is necessary to study the compressive mechanical properties of high ductile fiber reinforced concrete. On the basis of the previous research of the research group, the compressive strength, flexural strength, strength relationship, size effect and compressive constitutive model of high ductile fiber reinforced concrete (HFC) are studied by single factor contrast test. The main contents are as follows: (1) based on the previous research results of the research group, the compressive failure process, crack morphology, compressive failure mechanism and flexural failure process of high ductile fiber reinforced concrete (HFC) are studied, and the fiber content is also studied. The effects of four factors of fly ash content, water / binder ratio and sand / binder ratio as well as environmental factors on the compressive properties and flexural strength of high ductile fiber reinforced concrete are discussed. In order to provide some theoretical basis for the design and engineering application of high ductile fiber reinforced concrete. (2) based on the previous research results of the research group, the conversion relationship between cube compressive strength and axial compressive strength of high ductile fiber reinforced concrete and the conversion relationship of strength between different dimensions are studied. The ratio coefficient of axial compressive strength to cube compressive strength and the size effect coefficient of high ductile fiber reinforced concrete are determined. (3) based on the previous research results of the research group, uniaxial compression was carried out on the prism specimen, the stress-strain curve of the prism was measured, and the fiber content and water-binder ratio were analyzed. The influence of fly ash content and sand / binder ratio on the whole compression curve and the characteristic parameters on the curve is discussed. Then the corresponding constitutive model of compression is put forward. It provides a theoretical basis for the structural design and nonlinear numerical simulation of high ductile fiber reinforced concrete.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528.572

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