改性聚酯纤维在混凝土中的分散性及对耐久性的影响

发布时间：2018-04-01 09:29

本文选题：纤维性混凝土　切入点：聚酯纤维　出处：《工程科学学报》2016年11期

【摘要】：制备了不同纤维掺量的改性聚酯纤维混凝土,通过纤维分散的图像处理方法研究五种不同搅拌方式对改性聚酯纤维在混凝土中分散性能的影响,并通过耐久性试验研究改性聚酯纤维混凝土的抗碳化、抗氯盐侵蚀和抗冻性能.结果表明,图像处理方法能够较好地评价改性聚酯纤维混凝土中的纤维分散性,认为"砂石胶材60 s+水60 s+纤维60 s"的搅拌方式得到的纤维分散性最好,与肉眼观察的效果一致.掺加改性聚酯纤维能够提高混凝土的抗压强度,掺量为1.1 kg·m-3时提高强度14%左右,继续增大纤维掺量不能持续提升强度.改性聚酯纤维在混凝土中的密集分布能够削弱CO_2的扩散,降低混凝土的碳化速率12.6%~18.9%,纤维掺量越多,抗碳化能力越好.掺加改性聚酯纤维能够降低混凝土的氯离子扩散系数,提高其抗氯离子侵蚀能力.改性聚酯纤维还能有效减少冻融循环过程中表层材料的剥落,大大改善混凝土的抗冻性.
[Abstract]:Modified polyester fiber concrete with different fiber content was prepared. The effects of five different mixing methods on the dispersion properties of modified polyester fiber in concrete were studied by image processing method of fiber dispersion. The resistance to carbonation, chloride corrosion and freezing resistance of modified polyester fiber concrete is studied by durability test. The results show that the image processing method can evaluate the fiber dispersion in modified polyester fiber concrete. It is considered that the dispersion of the fibers obtained by the agitation method of "60 s water 60 s fiber" is the best, which is consistent with the effect of naked eye observation. The compressive strength of concrete can be improved by adding modified polyester fiber. The density distribution of modified polyester fiber in concrete can weaken the diffusion of CO_2, reduce the carbonation rate of concrete and reduce the carbonation rate of concrete. The better the carbonation resistance is, the better the addition of modified polyester fiber can reduce the chloride ion diffusion coefficient of concrete and improve its resistance to chloride ion erosion. The modified polyester fiber can also effectively reduce the spalling of surface materials during freeze-thaw cycle. Greatly improve the frost resistance of concrete.
【作者单位】：北京科技大学土木与环境工程学院;青岛理工大学土木工程学院;
【分类号】：TU528

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