许多研究人员使用纤维来提高沥青混合料的抗裂性能,但是关于纤维对断裂行为影响的研究还很有限。各种纤维类型(玄武岩纤维,玻璃纤维,和聚酯纤维)和含量(0.1%,0.2%,0.3%,0.4%,和0.5%)已使用间接拉伸沥青开裂试验(IDEAL-CT)结合数字图像相关(DIC)技术进行了研究。试验中使用的评价指标包括裂纹萌生能(Gif),裂纹能量(Gf),劈裂抗拉强度(RT),抗裂指数(CTindex),以及使用数字图像相关技术获得的实时拉伸应变(Exx)。结果表明,尽管纤维类型,纤维含量的增加首先导致了,增加,然后,沥青混合料的抗裂性降低,表明最佳纤维含量的存在-具体而言,0.4%,0.3%,玄武岩纤维为0.3%,玻璃纤维,和聚酯纤维,分别。实时拉伸应变的发展,基于数字图像相关技术,可分为两个阶段:缓慢增长阶段和快速扩张阶段。此外,含玄武岩纤维的沥青混合料在缓慢生长和快速膨胀阶段都表现出最佳的抗裂性。该研究有助于了解纤维种类和掺量对沥青混合料断裂行为的影响,对纤维在沥青混合料中的应用具有一定的参考意义。
Many researchers use fiber to improve the cracking resistance of asphalt mixtures, but research concerning the effects of fiber on fracture behavior is limited. The fracture behavior of asphalt mixtures with various fiber types (basalt fiber, glass fiber, and polyester fiber) and contents (0.1%, 0.2%, 0.3%, 0.4%, and 0.5%) has been studied using the indirect tensile asphalt cracking test (IDEAL-CT) in conjunction with digital image correlation (DIC) technology. The evaluation indexes used in the test included crack initiation energy (Gif), crack energy (Gf), splitting tensile strength (RT), cracking tolerance index (CTindex), and the real-time tensile strain (Exx) obtained using digital image correlation technology. The results showed that despite the fiber type, the increase of fiber content resulted in first, an increase, and then, a decrease of the cracking resistance of asphalt mixtures, indicating the presence of optimum fiber content-specifically, 0.4%, 0.3%, and 0.3% for basalt fiber, glass fiber, and polyester fiber, respectively. The development of real-time tensile strain, obtained based on digital image correlation technology, could be divided into two stages: slow-growth stage and rapid-expansion stage. In addition, asphalt mixture with basalt fiber presented the best cracking resistance at both the slow-growth and rapid-expansion stages. This research is helpful in understanding the effects of fiber type and content on the fracture behavior of asphalt mixtures and has certain reference significance for the application of fiber in asphalt mixtures.