Na Ilho, Park Hyemin, Yun Jihyeon, Park Ju Dong, Kim Hyunhwan
Barun Construction Technology, Youngin 16953, Republic of Korea.
Department of Engineering Technology, Texas State University, San Marcos, TX 78666, USA.
Materials (Basel). 2025 Jul 10;18(14):3265. doi: 10.3390/ma18143265.
Although asphalt mixtures can be applied to railway tracks due to their viscoelastic properties, caution is required, as their ductility and brittleness are highly sensitive to temperature variations. In recent years, interest in the application of asphalt in railway infrastructure has increased, driven by the development of modified mixtures and the broader availability of performance-enhancing additives. Additionally, evaluation methods for railway tracks should be adapted to account for the distinct loading mechanisms involved, which differ from those of conventional roadways. In this study, the comprehensive properties of asphalt binders, mixtures, and testing methods-including physical and engineering characteristics-were assessed to improve the performance of asphalt concrete layers for potential applications in railroad infrastructure. The results of this study indicate that (1) the higher the performance grade (PG), the higher the indirect tensile strength (ITS) value achieved by the 13 mm mixture using PG76-22, which is higher than that of the PG64-22 mixture. This indicates that higher PG grades and modification contribute to improved tensile strength, beneficial for upper layers subjected to dynamic railroad loads. (2) The tensile strength ratio (TSR) increased from the unmodified mixture to over 92% in mixtures containing crumb rubber modifier (CRM) and styrenic thermoplastic elastomer (STE), demonstrating enhanced durability under freeze-thaw conditions. (3) Wheel tracking test results showed that modified mixtures exhibited more than twice the rutting resistance compared to PG64-22. The 13 mm aggregate mixtures also generally performed better than the 19 mm mixtures, indicating reduced permanent deformation under repeated loading. (4) It was concluded that asphalt is a suitable material for railroads, as its overall characteristics comply with standard specifications.
尽管由于沥青混合料具有粘弹性，可应用于铁路轨道，但仍需谨慎，因为其延展性和脆性对温度变化高度敏感。近年来，由于改性混合料的发展以及性能增强添加剂的更广泛可得性，沥青在铁路基础设施中的应用受到了更多关注。此外，铁路轨道的评估方法应进行调整，以考虑到与传统道路不同的独特加载机制。在本研究中，对沥青结合料、混合料的综合性能以及测试方法（包括物理和工程特性）进行了评估，以改善沥青混凝土层在铁路基础设施潜在应用中的性能。本研究结果表明：（1）性能等级（PG）越高，使用PG76 - 22的13毫米混合料所达到的间接拉伸强度（ITS）值越高，该值高于PG64 - 22混合料。这表明较高的PG等级和改性有助于提高拉伸强度，有利于承受铁路动态荷载的上层结构。（2）拉伸强度比（TSR）从未改性混合料增加到含有橡胶粉改性剂（CRM）和苯乙烯类热塑性弹性体（STE）的混合料中的92%以上，表明在冻融条件下耐久性增强。（3）车辙试验结果表明，改性混合料的抗车辙能力是PG64 - 22的两倍以上。13毫米集料混合料通常也比19毫米混合料表现更好，表明在重复荷载下永久变形减小。（4）得出的结论是，沥青是铁路的合适材料，因为其总体特性符合标准规范。
