水泥基材料中钢纤维的方向控制及增强效应研究
发布时间：2018-11-06 19:46
【摘要】：纤维方向是影响水泥基材料中钢纤维增强效率的重要因素。通过外部磁场可以控制水泥基拌合物中钢纤维的方向,使纤维方向与磁感线方向相一致,钢纤维在该方向上的增强效率显著提高。混凝土中钢纤维的方向控制除了与磁场、浆体粘性有关外,还可能受到粗骨料以及邻近纤维(钢纤维掺量)的影响。基于以上认识,本文围绕钢纤维在混凝土中方向控制的影响因素以及定向后钢纤维对混凝土宏观性能的增强效应两个方面开展了一定的研究。主要研究内容如下:首先,分析了单根钢纤维在电磁定向过程中的受力情况以及运动状态的变化规律,在此基础上确定了控制水泥基拌合物中钢纤维方向的方法。研究了常用各种形状钢纤维在水泥浆中通过磁场控制其方向时的受力情况,分析了纤维形状对钢纤维方向控制的影响。与普通圆直形钢纤维相比,异形钢纤维由于定向过程中磁场力或浆体绕流阻力的变化,使纤维在水泥浆体中定向时所需时间均有不同程度的改变。接着,以混凝土为研究对象,分析了粗骨料以及纤维掺量对钢纤维电磁定向及分布效果的影响,研究了其作用机理。最后,简要分析了不同纤维方向系数的钢纤维混凝土劈裂抗拉、抗剪性能,通过实验对不同纤维掺量的单向钢纤维混凝土的劈裂抗拉、抗剪性能进行了验证,证明了纤维定向对混凝土材料宏观性能的影响规律。由研究可知,通过有效控制磁场强度、水泥基粘性、钢纤维掺量以及粗骨料可以制备出纤维方向较为一致的单向分布钢纤维混凝土,使混凝土材料的力学性能显著提高,增韧、阻裂效果更好。
[Abstract]:The direction of fiber is an important factor affecting the reinforcement efficiency of steel fiber in cement-based materials. The direction of steel fiber in cement based mixture can be controlled by external magnetic field, and the direction of fiber is consistent with the direction of magnetic induction line, and the enhancement efficiency of steel fiber in this direction is improved significantly. The direction control of steel fiber in concrete is not only related to magnetic field and paste viscosity, but also affected by coarse aggregate and adjoining fiber (steel fiber content). Based on the above understanding, this paper focuses on the influence factors of steel fiber in the direction control of concrete and the enhancement effect of oriented steel fiber on the macroscopic properties of concrete. The main research contents are as follows: firstly, the stress and motion of a single steel fiber during electromagnetic orientation are analyzed, and the method of controlling the direction of steel fiber in cement based mixture is determined. The influence of the shape of steel fiber on the direction control of steel fiber in cement slurry is studied. The influence of fiber shape on the direction control of steel fiber is analyzed. Compared with the normal circular straight steel fiber, the time required for the fiber orientation in the cement paste varies in varying degrees due to the change of magnetic field force or slurry flow resistance during the orientation process of the special-shaped steel fiber. Then, the effect of coarse aggregate and fiber content on the electromagnetic orientation and distribution of steel fiber is analyzed, and its mechanism is studied. Finally, the splitting tensile and shear properties of steel fiber reinforced concrete with different fiber direction coefficients are briefly analyzed, and the splitting tensile and shear properties of unidirectional steel fiber reinforced concrete with different fiber content are verified by experiments. The effect of fiber orientation on the macroscopic properties of concrete is proved. The results show that unidirectional distributed steel fiber concrete with the same fiber direction can be prepared by effectively controlling the magnetic field strength, cement viscosity, steel fiber content and coarse aggregate. The mechanical properties and toughness of concrete can be improved significantly. The anti-cracking effect is better.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528.572
本文编号：2315284
[Abstract]:The direction of fiber is an important factor affecting the reinforcement efficiency of steel fiber in cement-based materials. The direction of steel fiber in cement based mixture can be controlled by external magnetic field, and the direction of fiber is consistent with the direction of magnetic induction line, and the enhancement efficiency of steel fiber in this direction is improved significantly. The direction control of steel fiber in concrete is not only related to magnetic field and paste viscosity, but also affected by coarse aggregate and adjoining fiber (steel fiber content). Based on the above understanding, this paper focuses on the influence factors of steel fiber in the direction control of concrete and the enhancement effect of oriented steel fiber on the macroscopic properties of concrete. The main research contents are as follows: firstly, the stress and motion of a single steel fiber during electromagnetic orientation are analyzed, and the method of controlling the direction of steel fiber in cement based mixture is determined. The influence of the shape of steel fiber on the direction control of steel fiber in cement slurry is studied. The influence of fiber shape on the direction control of steel fiber is analyzed. Compared with the normal circular straight steel fiber, the time required for the fiber orientation in the cement paste varies in varying degrees due to the change of magnetic field force or slurry flow resistance during the orientation process of the special-shaped steel fiber. Then, the effect of coarse aggregate and fiber content on the electromagnetic orientation and distribution of steel fiber is analyzed, and its mechanism is studied. Finally, the splitting tensile and shear properties of steel fiber reinforced concrete with different fiber direction coefficients are briefly analyzed, and the splitting tensile and shear properties of unidirectional steel fiber reinforced concrete with different fiber content are verified by experiments. The effect of fiber orientation on the macroscopic properties of concrete is proved. The results show that unidirectional distributed steel fiber concrete with the same fiber direction can be prepared by effectively controlling the magnetic field strength, cement viscosity, steel fiber content and coarse aggregate. The mechanical properties and toughness of concrete can be improved significantly. The anti-cracking effect is better.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528.572
【参考文献】
相关硕士学位论文 前1条
1 刘慧;基于CT图像处理的冻融岩石细观损伤特性研究[D];西安科技大学;2006年
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