【摘要】：纖維方向是影響水泥基材料中鋼纖維增強(qiáng)效率的重要因素。通過外部磁場可以控制水泥基拌合物中鋼纖維的方向,使纖維方向與磁感線方向相一致,鋼纖維在該方向上的增強(qiáng)效率顯著提高�；炷林袖摾w維的方向控制除了與磁場、漿體粘性有關(guān)外,還可能受到粗骨料以及鄰近纖維(鋼纖維摻量)的影響�；谝陨险J(rèn)識(shí),本文圍繞鋼纖維在混凝土中方向控制的影響因素以及定向后鋼纖維對混凝土宏觀性能的增強(qiáng)效應(yīng)兩個(gè)方面開展了一定的研究。主要研究內(nèi)容如下:首先,分析了單根鋼纖維在電磁定向過程中的受力情況以及運(yùn)動(dòng)狀態(tài)的變化規(guī)律,在此基礎(chǔ)上確定了控制水泥基拌合物中鋼纖維方向的方法。研究了常用各種形狀鋼纖維在水泥漿中通過磁場控制其方向時(shí)的受力情況,分析了纖維形狀對鋼纖維方向控制的影響。與普通圓直形鋼纖維相比,異形鋼纖維由于定向過程中磁場力或漿體繞流阻力的變化,使纖維在水泥漿體中定向時(shí)所需時(shí)間均有不同程度的改變。接著,以混凝土為研究對象,分析了粗骨料以及纖維摻量對鋼纖維電磁定向及分布效果的影響,研究了其作用機(jī)理。最后,簡要分析了不同纖維方向系數(shù)的鋼纖維混凝土劈裂抗拉、抗剪性能,通過實(shí)驗(yàn)對不同纖維摻量的單向鋼纖維混凝土的劈裂抗拉、抗剪性能進(jìn)行了驗(yàn)證,證明了纖維定向?qū)炷敛牧虾暧^性能的影響規(guī)律。由研究可知,通過有效控制磁場強(qiáng)度、水泥基粘性、鋼纖維摻量以及粗骨料可以制備出纖維方向較為一致的單向分布鋼纖維混凝土,使混凝土材料的力學(xué)性能顯著提高,增韌、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.
【學(xué)位授予單位】：河北工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU528.572

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本文編號(hào)：2315284