超高分子量聚乙烯纤维混凝土静态力学性能研究

发布时间：2018-02-02 10:04

本文关键词： UHMWPE 纤维增强混凝土静态强度变形特性试验　出处：《工程科学与技术》2017年S2期 　论文类型：期刊论文

【摘要】：纤维混凝土较普通混凝土具有更加优异的阻裂、增强和增韧效果,能更好地满足现代混凝土工程设施的要求。作者以高强、高弹模、低密度的捻制超高分子量聚乙烯(UHMWPE)纤维作为增强体,试验研究一种新型纤维混凝土的准静态力学性能。通过改进制备流程,研制C70等级的4种纤维体积掺量纤维混凝土,通过劈裂抗拉、立方体抗压和棱柱体轴心压缩试验,研究纤维掺量对混凝土强度和变形性能的影响。最后,试验结果与未处理UHMWPE纤维混凝土及聚丙烯纤维混凝土进行对比。结果表明:改进的制备工艺提高了纤维在混凝土中的分散均匀性,改善了混凝土的和易性;纤维使混凝土试件破坏时保持了良好的整体性,避免了大量碎块的脱落;UHMWPE纤维显著提高了混凝土劈裂抗拉强度,当纤维掺量为0.3%~1.0%时,强度提高率为47.2%~78.6%;纤维对混凝土单轴抗压强度作用不明显,但极大改善了残余抗压强度;压缩峰值应变及泊松比随纤维掺量增加而增大,弹性模量则相反,压缩韧性指数ηc15.5为素混凝土的1.40倍~2.53倍;捻制UHMWPE纤维较其他两种纤维更加显著地改善了混凝土的劈裂抗拉强度,并对单轴抗压强度有一定的增强效果。
[Abstract]:Compared with ordinary concrete, fiber reinforced concrete has more excellent crack resistance, strengthening and toughening effect, and can better meet the requirements of modern concrete engineering facilities. The author uses high strength and high elastic modulus. The quasi static mechanical properties of a new fiber reinforced UHMWPE fiber with low density were studied. The preparation process was improved. Four kinds of fiber volume concrete of C70 grade were developed. The effects of fiber content on the strength and deformation properties of concrete were studied by splitting tensile test, cube compression test and prism axial compression test. The experimental results are compared with untreated UHMWPE fiber concrete and polypropylene fiber reinforced concrete. The results show that the improved preparation technology improves the dispersion uniformity of fiber in concrete. Improved the ease of concrete; The fiber makes the concrete specimen maintain good integrity and avoid the fall off of a large number of fragments. The tensile strength of the concrete was significantly increased by UHMWPE fiber, and when the fiber content was 0.3-1.0, the increase rate of the strength was 47.2% and 78.6%. The effect of fiber on uniaxial compressive strength of concrete is not obvious, but the residual compressive strength is greatly improved. The compressive peak strain and Poisson's ratio increase with the increase of fiber content, whereas the elastic modulus is opposite. The compressive toughness index 畏 c 15.5 is 1.40 times and 2.53 times of that of plain concrete. Compared with the other two kinds of fibers, the twisting UHMWPE fiber improves the splitting tensile strength of concrete and enhances the uniaxial compressive strength to a certain extent.
【作者单位】：国防科技大学指挥军官基础教育学院;诺丁汉大学工程学院;海军工程大学;
【基金】：国防工程资助项目(参训2013813)
【分类号】：TU528.572
【正文快照】： 混凝土是一种普遍应用于各类工程设施的建筑材料,在混凝土中掺入分散短纤维,可以很好地弥补材料本身抗拉强度低和韧性差的不足[1],改善混凝土在正常工作状态和极端荷载作用下的抗裂、耐冲击性能[2],提高工程结构的耐久性和安全防护能力。纤维对混凝土的增强增韧作用主要取决于

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