Smarzewski Piotr, Jancy Anna
Faculty of Civil Engineering and Geodesy, Military University of Technology, 2 Gen. Sylwestra Kaliskiego, 00908 Warsaw, Poland.
Materials (Basel). 2025 Aug 15;18(16):3833. doi: 10.3390/ma18163833.
This study investigates the flexural performance, tensile splitting strength, and fracture behaviour of self-compacting concrete (SCC) reinforced with polypropylene (PP) and basalt (BF) fibres. A total of eleven SCC mixtures with varying fibre types and volume fractions (0.025-0.25%) were tested at 7 and 28 days. In this study, the term high-performance concrete (HPC) refers to SCC mixtures with a 28-day compressive strength exceeding 60 MPa, as commonly accepted in European standards and literature. The control SCC achieved 68.2 MPa at 28 days. While fibre addition enhanced the tensile and flexural properties, it reduced workability, demonstrating the trade-off between mechanical performance and flowability in high-performance SCC. The experimental results demonstrate that both fibre types improve the tensile behaviour of SCC, with distinct performance patterns. PP fibres, owing to their flexibility and crack-bridging capability, were particularly effective at early ages, enhancing the splitting tensile strength by up to 45% and flexural toughness by over 300% at an optimal dosage of 0.125%. In contrast, BF fibres significantly increased the 28-day toughness (up to 15.7 J) and post-cracking resistance due to their superior stiffness and bonding with the matrix. However, high fibre contents adversely affected workability, particularly in BF-reinforced mixes. The findings highlight a dosage-sensitive behaviour, with optimum performance observed at 0.05-0.125% for PP and 0.125-0.25% for BF. While PP fibres improve crack distribution and early-age ductility, BF fibres offer higher stiffness and energy absorption in post-peak regimes. Statistical analysis (ANOVA and Tukey's test) confirmed significant differences in the mechanical performance among fibre-reinforced mixes. The study provides insights into selecting appropriate fibre types and dosages for SCC structural applications. Further research on hybrid fibre systems and long-term durability is recommended. The results contribute to sustainable concrete design by promoting enhanced performance with low-volume, non-metallic fibres.
本研究调查了用聚丙烯（PP）和玄武岩（BF）纤维增强的自密实混凝土（SCC）的弯曲性能、劈裂抗拉强度和断裂行为。总共对11种不同纤维类型和体积分数（0.025 - 0.25%）的SCC混合物在7天和28天时进行了测试。在本研究中，高性能混凝土（HPC）一词指的是28天抗压强度超过60 MPa的SCC混合物，这是欧洲标准和文献中普遍认可的。对照SCC在28天时达到了68.2 MPa。虽然添加纤维增强了拉伸和弯曲性能，但降低了工作性，这表明在高性能SCC中机械性能和流动性之间存在权衡。实验结果表明，两种纤维类型都改善了SCC的拉伸性能，具有不同的性能模式。PP纤维由于其柔韧性和裂缝桥接能力，在早期特别有效，在最佳剂量0.125%时，劈裂抗拉强度提高了45%，弯曲韧性提高了300%以上。相比之下，BF纤维由于其优越的刚度和与基体的粘结力，显著提高了28天的韧性（高达15.7 J）和开裂后抗性。然而，高纤维含量对工作性有不利影响，特别是在BF增强的混合物中。研究结果突出了剂量敏感行为，PP纤维在0.05 - 0.125%、BF纤维在0.125 - 0.25%时观察到最佳性能。虽然PP纤维改善了裂缝分布和早期延性，但BF纤维在峰值后阶段提供了更高的刚度和能量吸收。统计分析（方差分析和Tukey检验）证实了纤维增强混合物之间机械性能的显著差异。该研究为SCC结构应用中选择合适的纤维类型和剂量提供了见解。建议对混合纤维系统和长期耐久性进行进一步研究。这些结果通过推广使用低体积、非金属纤维提高性能，为可持续混凝土设计做出了贡献。
