纤维混凝土抗裂性能试验研究及分析

发布时间：2018-04-10 21:54

本文选题：纤维 + 混凝土　；参考：《南京理工大学》2013年硕士论文

【摘要】：混凝土是目前建筑市场上的主要建筑材料,它具有整体性强,可模性好,工程造价低,维护方便,耐久性强等优点。但是,混凝土作为建筑材料也有一定的性能缺陷,抗裂性能差就是其主要缺点之一,如何提高混凝土的抗裂性能具有重要的工程意义。本文主要通过平板早期塑性收缩试验,对素混凝土、钢纤维混凝土、聚丙烯腈纤维混凝土以及钢-聚丙烯腈纤维混凝土的早期塑性开裂进行试验研究,探讨纤维对混凝土基体的抗裂性能的影响。通过ANSYS建立的包含有随机分布纤维的模型模拟分析了不同长度、不同掺量对混凝土立方体的强度增强效果。最后通过一个纤维混凝土剪力墙模型,模拟纤维混凝土在实际工程构件中的受力和抗裂性能增强效果。得到如下主要结论： (1)在平板开裂试验中,通过对比素混凝土,钢纤维混凝土、聚丙烯腈纤维混凝土、钢-聚丙烯腈混杂纤维混凝土的早期塑性收缩开裂情况,发现钢-聚丙烯腈混杂纤维混凝土的抗裂性能最好。 (2)通过在ANSYS中建立一个包含纤维随机分布的立方体模型模拟计算得出其应力-应变曲线,通过曲线可以一定程度上分析得出不同纤维长度和不同纤维间距对混凝土基体的各个性能的增强效果。通过分析立方体模型的剪应力云图得出纤维的最佳间距和最佳长度。 (3)对纤维最佳间距进行了探讨分析,通过一个固定长度的纤维在模型中不同间距下受力产生的应力云图,分析得出纤维最佳间距。 (4)通过在ANSYS中建立不同纤维掺量的剪力墙模型,分析探讨了纤维混凝土在实际工程构件中的受力状况,得出剪力墙的开裂荷载、屈服荷载和极限荷载随着钢纤维体积率的提高而提高,极限位移也不断增大。最后,总结了本文的主要研究内容和所得到的结论,并对本文研究的不足之处予以说明。
[Abstract]:Concrete is the main building material in the construction market at present. It has the advantages of strong integrity, good modularity, low engineering cost, convenient maintenance, strong durability and so on.However, concrete as a building material also has some performance defects, the poor crack resistance is one of its main shortcomings, how to improve the crack resistance of concrete has important engineering significance.In this paper, the early plastic cracking of plain concrete, steel fiber concrete, polyacrylonitrile fiber concrete and steel-polyacrylonitrile fiber concrete is studied by the early plastic shrinkage test of flat plate.The effect of fiber on crack resistance of concrete matrix is discussed.The strength enhancement effect of concrete cubes with different lengths and different admixtures is simulated and analyzed by using a model with randomly distributed fibers established by ANSYS.Finally, a fiber reinforced concrete shear wall model is used to simulate the strengthening effect of fiber reinforced concrete in practical engineering members.The main conclusions are as follows:In plate cracking test, the early plastic shrinkage cracking of plain concrete, steel fiber concrete, polyacrylonitrile fiber concrete and steel-polyacrylonitrile hybrid fiber concrete was compared.It is found that steel-polyacrylonitrile hybrid fiber reinforced concrete has the best crack resistance.2) the stress-strain curve is obtained by establishing a cube model containing random distribution of fibers in ANSYS.The effect of different fiber length and fiber spacing on the performance of concrete matrix can be analyzed to a certain extent by the curve.The optimum spacing and length of the fibers are obtained by analyzing the shear stress cloud diagram of the cube model.3) the optimum spacing of fibers is discussed and analyzed, and the optimum spacing of fibers is obtained by analyzing the stress cloud diagram of a fixed length fiber under different spacing in the model.4) through establishing the shear wall model with different fiber content in ANSYS, the stress condition of fiber reinforced concrete in practical engineering members is analyzed and discussed, and the cracking load of shear wall is obtained.The yield load and ultimate load increase with the increase of steel fiber volume ratio, and the ultimate displacement increases.Finally, the main contents and conclusions of this paper are summarized, and the shortcomings of this study are explained.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528.572

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