【摘要】 超高性能混凝土脆性大和韧性差，常用微丝钢纤维改善其脆性，但微丝钢纤维存在锈蚀等问题。本文针对钢纤维的问题，用高强尼龙纤维取代钢纤维，并采用对比试验方法，研究了高强尼龙纤维、聚丙烯纤维和聚乙烯醇纤维对超高性能混凝土的强度性能、弯曲韧性、抗冲击性的影响，同时初步探讨纤维在超高性能混凝土中的作用机理。结果表明：三种合成纤维对超高性能混凝土的抗压强度和抗弯强度影响不大，对劈裂抗拉强度有显著改善作用，合成纤维与基体黏结效果不同使得纤维的效果不同；聚乙烯醇纤维和高强尼龙纤维对弯曲韧性有一定改善作用；高强尼龙纤维制备的超高性能混凝土具有更好的抗冲击性能；三种纤维中，高强尼龙纤维最适合制备装饰用超性能混凝土。更多还原

【Abstract】 Ultra-high-performance concrete(UHPC) has high brittleness and poor toughness, and commonly used micro wire steel fibers to improve its brittleness. However, there are problems such as rusting of micro wire steel fibers. This article focused on the issue of steel fibers and replaced them by high-strength nylon fiber. A comparative experimental method was used to study the effects of high-strength nylon fibers, with polypropylene(PP) fiber and polyvinyl alcohol(PVA) fiber on the strength properties, bending toughness, and impact resistance of UHPC. At the same time, the mechanism of fiber action in UHPC was preliminarily explored. The results showed that the three synthetic fibers have little effect on the compressive strength and flexural strength of UHPC, but significantly improve the splitting-tensile strength. The different bonding strength between synthetic fibers and matrix results in different effects of fibers. PVA fiber and high-strength nylon fiber have certain improvement effect on flexural toughness. UHPC prepared by high-strength nylon fiber has better impact resistance. Among the three types synthetic fibers, high-strength nylon fiber is the most suitable for preparing UHPC for decoration.更多还原