聚丙烯粗纤维混凝土性能试验研究

发布时间：2018-03-07 14:03

本文选题：聚丙烯纤维　切入点：混凝土　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：现代土木工程中,水泥混凝土已经成为不可缺少的一种建筑材料。普通混凝土由于其固有的缺点限制了其发展应用。聚丙烯纤维是一种新型的水泥基复合材料增强纤维,其具有很多优点。因此,开展聚丙烯纤维混凝土研究对推广聚丙烯纤维在混凝土工程中的应用具有积极的意义。本文通过掺加不同数量聚丙烯粗纤维以及聚丙烯粗纤维和细纤维混合使用,研究了聚丙烯粗纤维和粗细混合纤维对混凝土拌合物的工作性、混凝土的力学性能以及部分耐久性的影响进行了试验研究,为合理使用聚丙烯粗纤维提供了依据。研究结果表明单掺聚丙烯粗纤维,随着纤维含量的增加,新拌混凝土的坍落度降低、含气量增大,特别是当掺量达到6.0kg/m3时,坍落度明显降低。聚丙烯粗纤维掺入混凝土后,混凝土7d和28d抗压强度随掺量的增加呈现降低的趋势,但各掺量聚丙烯粗纤维混凝土7d和28d抗压强度降低幅度不大;混凝土的7d和28d劈裂强度、抗折强度与基准混凝土基本一致或略有减低;混凝土的抗冲击性能随纤维掺量的增加而增加,其中混掺聚丙烯粗纤维和细纤维对混凝土的抗冲击性能影响最大,与基准混凝土相比,纤维掺量为(1.6+6.0)kg/m3时,冲击韧性增加了大约3.6倍。掺入聚丙烯粗纤维后,混凝土各龄期的收缩率、碳化深度与基准混凝土基本一致或略小。
[Abstract]:In modern civil engineering, cement concrete has become an indispensable building material. Ordinary concrete has limited its development and application because of its inherent shortcomings. Polypropylene fiber is a new type of cement matrix composite reinforced fiber. It has many advantages. Therefore, The study of polypropylene fiber concrete has positive significance for popularizing the application of polypropylene fiber in concrete engineering. The effects of polypropylene fiber and coarse fiber on the workability, mechanical properties and partial durability of concrete were studied. The results show that with the increase of fiber content, the slump of fresh concrete decreases and the gas content increases, especially when the content of raw polypropylene fiber reaches 6.0 kg / m ~ 3. The slump decreased obviously. The compressive strength of the concrete decreased with the increase of the content of PP coarse fiber, but the compressive strength of the coarse polypropylene fiber reinforced concrete was not decreased by 7 days and 28 days after the addition of polypropylene fiber into the concrete, and the compressive strength of the concrete decreased with the increase of the content of PP fiber. The fracture strength of concrete at 7d and 28d is basically the same as that of standard concrete, and the impact resistance of concrete increases with the increase of fiber content. The impact resistance of concrete was greatly affected by blending polypropylene coarse fiber and fine fiber. Compared with the reference concrete, the impact toughness of the concrete was increased by 3.6 times when the fiber content was 1.6. 0 kg / m 3. When the polypropylene fiber was added, the impact toughness of the concrete was 3.6 times higher than that of the reference concrete. The shrinkage rate and carbonation depth of concrete at each age are basically the same or slightly smaller than those of reference concrete.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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