Due to the outstanding mechanical properties of the reactive powder concrete (RPC), it has attracted a great deal of attention. In which, incorporating fibers can improve its behavior and properties. The main objectives of this study were to consider different mixing methods and the effect of fiber content and type on the mechanical properties of RPC. The best mix proportion was selected for the final tests among 13 initial mix designs based on the 7-day compressive strength and flow value of the fresh concrete. Different macro and microfibers (including steel, polyvinyl alcohol, glass, carbon, and basalt fibers) with volume fractions of 0.5% and 1.5% were added to the final RPC mix by two different mixing methods, and mechanical properties such as compressive, tensile, and flexural strengths and energy absorption capability were investigated. Based on the results of experiments, the addition of 1.5% hybrid (macro and micro) steel fibers had the most positive effect on increasing the mechanical properties of RPC compared to other fibers. The hybrid fibers increased the compressive, tensile, and flexural strengths and flexural toughness of the specimens by 42.5%, 26.9%, 87.6%, and 396%, respectively. According to the results, the addition of 0.5% fibers to RPC did not significantly enhance the mechanical properties of the concrete.

中文翻译：

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粗细纤维对活性粉末混凝土力学性能影响的试验研究

由于反应性粉末混凝土（RPC）优异的力学性能，引起了广泛的关注。其中，掺入纤维可以改善其行为和性能。本研究的主要目的是考虑不同的混合方法以及纤维含量和类型对 RPC 机械性能的影响。根据新拌混凝土的 7 天抗压强度和流动值，在 13 种初始配合比设计中选择最佳配合比进行最终试验。通过两种不同的混合方法，将体积分数分别为 0.5% 和 1.5% 的不同粗纤维和超细纤维（包括钢、聚乙烯醇、玻璃、碳和玄武岩纤维）添加到最终的 RPC 混合物中，以及压缩、拉伸、并研究了弯曲强度和能量吸收能力。根据实验结果，与其他纤维相比，添加 1.5% 混合（宏观和微观）钢纤维对提高 RPC 的机械性能具有最积极的影响。混合纤维将试样的抗压、抗拉、抗弯强度和抗弯韧性分别提高了 42.5%、26.9%、87.6% 和 396%。结果表明，在 RPC 中添加 0.5% 的纤维并没有显着提高混凝土的力学性能。