单向钢纤维增强水泥砂浆的各向异性研究

发布时间：2018-02-25 17:13

本文关键词： 单向钢纤维增强水泥基复合材料纤维定向纤维方向效应系数劈拉强度弯曲强度抗剪强度各向异性　出处：《河北工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：对钢纤维水泥基拌合物施加磁场,可使其中钢纤维方向与磁感应方向趋于一致,硬化后制备出单向钢纤维增强水泥基材料。单向钢纤维水泥基材料在纤维增强方向上,韧性、延性、强度等得到极大增强和提高。然而,由于钢纤维的规律性分布,单向钢纤维水泥基材料成为一种各向异性材料。目前的研究主要集中在纤维增强方向上的性能变化,非纤维增强方向上的性能尚待进一步分析研究。针对这种情况,本文对制备的单向钢纤维水泥基材料力学性能的各向异性性能进行试验研究。主要内容如下:1.研究电磁定向阶段钢纤维在水泥基材料中的运动规律,分析了磁场强度、钢纤维特征、水泥浆体粘度对钢纤维定向运动过程的影响,确定了控制水泥基中钢纤维方向的方法。2.分析了钢纤维方向性对水泥砂浆劈裂抗拉性能的影响,测试了单向钢纤维砂浆不同方向的劈裂抗拉强度,分析其各向异性,并对其破坏特征进行分析研究。钢纤维掺量和不同基体强度时钢纤维增强砂浆的劈裂抗拉强度各向异性,分析了不同纤维方向上的拉压比与抗压强度和劈裂抗拉强度之间的关系。3.分析了单向钢纤维对水泥砂浆抗弯性能的增强机理,根据机理建立单向钢纤维增强砂浆的抗弯强度模型。对单向钢纤维增强水泥砂浆抗弯各向异性进行了试验研究,测试了不同纤维方向时的弯曲荷载-挠度曲线、弯曲强度、弯曲韧度等性能。4.试验研究单向钢纤维增强水泥砂浆不同方向的抗剪性能,分析其抗剪各向异性,同时与普通钢纤维水泥砂浆的抗剪性能对比,并对单向钢纤维水泥砂浆不同纤维方向上的破坏形态进行分析研究。5.分析了钢纤维方向性对水泥砂浆抗压强度的影响机理,并对抗压强度各向异性进行试验研究,测试了不同纤维方向时的抗压强度,同时与普通钢纤维水泥砂浆的抗压性能对比,并对其破坏形态进行分析。
[Abstract]:When the magnetic field is applied to the steel fiber cement base mixture, the direction of the steel fiber and the magnetic induction direction tend to be the same, and the unidirectional steel fiber reinforced cement base material is prepared after hardening. The unidirectional steel fiber cement base material is tenacity in the fiber reinforcement direction. Ductility and strength are greatly enhanced and improved. However, due to the regular distribution of steel fibers, unidirectional steel fiber cement materials become an anisotropic material. The performance in the non-fiber reinforcement direction needs further analysis and study. In this paper, the anisotropy of mechanical properties of unidirectional steel fiber cement-based materials is studied. The main contents are as follows: 1. The movement of steel fibers in cement-based materials during electromagnetic orientation is studied, and the magnetic field strength is analyzed. The influence of the characteristics of steel fiber and the viscosity of cement paste on the directional movement process of steel fiber is determined. The method of controlling the direction of steel fiber in cement matrix is determined. The influence of steel fiber directivity on the splitting and tensile properties of cement mortar is analyzed. The splitting tensile strength in different directions of unidirectional steel fiber mortar is tested, its anisotropy is analyzed, and its failure characteristics are studied. The splitting tensile strength anisotropy of steel fiber reinforced mortar is studied when the steel fiber content and the different matrix strength are different. The relationship between tensile compression ratio in different fiber directions and compressive strength and splitting tensile strength is analyzed. 3. The strengthening mechanism of unidirectional steel fiber on the flexural properties of cement mortar is analyzed. The flexural strength model of unidirectional steel fiber reinforced mortar was established according to the mechanism. The bending anisotropy of unidirectional steel fiber reinforced cement mortar was studied experimentally. The bending load-deflection curve and bending strength of unidirectional steel fiber reinforced cement mortar were measured. The shear resistance of unidirectional steel fiber reinforced cement mortar in different directions is studied, and its shear anisotropy is analyzed. At the same time, the shear resistance of unidirectional steel fiber reinforced cement mortar is compared with that of ordinary steel fiber cement mortar. The failure patterns of unidirectional steel fiber cement mortar in different fiber directions are analyzed. 5. The influence mechanism of steel fiber directivity on the compressive strength of cement mortar is analyzed, and the anisotropy of compressive strength is studied experimentally. The compressive strength of the cement mortar with different fiber directions was tested and the compressive strength of the mortar was compared with that of the ordinary steel fiber cement mortar. The failure mode of the mortar was analyzed.
【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】：TQ177.62

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