天然浮石轻骨料混凝土复合聚丙烯纤维后性能的改善

发布时间：2019-01-05 02:49

【摘要】：内蒙古自治区是盛产天然浮石的地方。浮石作为轻骨料混凝土中粗集料的一种具有独到的优势。当然,也会存有一些自我无法弥补的缺陷。本文希望通过聚丙烯纤维来增进天然浮石轻骨料混凝土的韧性,减少、控制混凝土塑性收缩裂缝的生成和发展,进而提高其力学性能和耐久性。据了解,国内外对聚丙烯纤维混凝土和轻骨料混凝土研究已经很发达,并发现了两种混凝土的诸多优点,但对聚丙烯纤维浮石轻骨料混凝土的研究还没有具体结论(尤其在国内),并且天然浮石本身还具有地区特性(与火山周围的环境、喷发时间段的天气状况等息息相关)。所以,对浮石轻骨料混凝土加入聚丙烯纤维研究具有很大的意义的。本文在LC25、LC30浮石轻骨料混凝土中掺入不同掺量的聚丙烯纤维组成试验组,进行力学试验和抗冻试验,依据试验结果和现象研究聚丙烯纤维对浮石轻骨料混凝土性能的影响、分析其影响机理,并定量分析出纤维的最佳掺量。最后,对聚丙烯纤维轻骨料混凝土进行抗冻耐久性的D-N模型预测和对、LC30混凝土进行冻融损伤方程演化。经试验整理、分析得出：在本试验纤维掺量范围内,聚丙烯纤维对浮石轻骨料混凝土的力学性能和抗冻性能具有改善作用,这可为工程实践提供理论基础。
[Abstract]:Inner Mongolia Autonomous region is rich in natural pumice. Pumice as a coarse aggregate in lightweight aggregate concrete has a unique advantage. Of course, there will be some self-irreparable defects. This paper hopes to improve the toughness of natural pumice lightweight aggregate concrete through polypropylene fiber, reduce and control the formation and development of plastic shrinkage cracks of concrete, and then improve its mechanical properties and durability. It is understood that the research on polypropylene fiber reinforced concrete and lightweight aggregate concrete has been well developed at home and abroad, and has found many advantages of the two kinds of concrete. However, the study of polypropylene fiber pumice lightweight aggregate concrete has no concrete conclusion (especially in China), and the natural pumice itself also has regional characteristics (closely related to the environment around the volcano, the weather conditions of the eruption period, etc.). Therefore, it is of great significance to study the addition of polypropylene fiber to pumice lightweight aggregate concrete. In this paper, the effects of polypropylene fiber on the properties of pumice lightweight aggregate concrete were studied according to the experimental results and phenomena. The influence mechanism of the fiber was analyzed and the optimum content of fiber was quantitatively analyzed. Finally, the D-N model is used to predict the freezing durability of polypropylene fiber lightweight aggregate concrete and the damage equation of freeze-thaw damage of LC30 concrete is developed. It is concluded that polypropylene fiber can improve the mechanical properties and frost resistance of pumice lightweight aggregate concrete in the range of fiber content, which can provide a theoretical basis for engineering practice.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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