Birol Tamer, Avcıalp Alper
Department of Civil Engineering, Balıkesir University, 10145 Balıkesir, Türkiye.
Institute of Science, Balıkesir University, 10145 Balıkesir, Türkiye.
Polymers (Basel). 2025 Apr 30;17(9):1232. doi: 10.3390/polym17091232.
Steel fibers are frequently used in ultra high-performance concrete (UHPC) due to their superior properties, but they also have disadvantages, such as corrosion exposure, high specific gravity and high cost. Although synthetic fibers have emerged as an alternative, the focus has generally been on hybrid use with steel fibers in UHPC. This study investigates the applicability of macro-polypropylene (PP) fibers for UHPC in terms of mechanical properties. An experimental campaign was conducted for UHPC mixtures containing macro-PP fibers with varying volumetric ratios. The effects of macro-PP fiber on the mechanical properties of UHPC were investigated in terms of compressive strength, splitting tensile strength and flexural behavior. The two-dimensional digital image correlation (2D-DIC) method was adopted to examine the cracking behavior. In addition, tensile constitutive law for UHPC mixtures was obtained with inverse analysis based on Model Code 2020 (MC2020). The results showed that the use of macro-PP fibers had no significant impact on compressive and splitting tensile strength. However, residual flexural tensile strength and fracture energy increased by up to 2.8 and 2.5 times, respectively, compared to UHPC without fiber. It was determined that macro-PP fibers could exhibit effective crack control in UHPC.
由于具有优异的性能，钢纤维常用于超高性能混凝土（UHPC）中，但它们也有缺点，如易受腐蚀、比重高和成本高。尽管合成纤维已成为一种替代品，但在超高性能混凝土中，人们通常将重点放在与钢纤维混合使用上。本研究从力学性能方面研究了宏观聚丙烯（PP）纤维在超高性能混凝土中的适用性。对含有不同体积比宏观PP纤维的超高性能混凝土混合物进行了试验。从抗压强度、劈裂抗拉强度和弯曲性能方面研究了宏观PP纤维对超高性能混凝土力学性能的影响。采用二维数字图像相关（2D-DIC）方法研究开裂行为。此外，基于《2020年模型规范》（MC2020）通过反分析得到了超高性能混凝土混合物的拉伸本构关系。结果表明，宏观PP纤维的使用对抗压强度和劈裂抗拉强度没有显著影响。然而，与无纤维的超高性能混凝土相比，残余弯曲抗拉强度和断裂能分别提高了2.8倍和2.5倍。研究确定，宏观PP纤维在超高性能混凝土中能有效控制裂缝。
