Fatigue behavior evaluation of two full-scale composite ballastless slab tracks incorporating steel and glass fiber rods

Innovations in railway infrastructure, such as ballastless slab tracks, are advancing modern railway transportation. However, these technologies also bring challenges, particularly the risks of corrosion and electrical conductivity associated with the steel bars used in slab tracks and sleepers, which can negatively affect their long-term performance. To address these issues, composite reinforcement materials like glass fiber-reinforced polymer (GFRP) bars, already used in various applications, offer a promising alternative for slab tracks and sleepers. In this experimental comparative study, two full-scale slab track specimens, one reinforced with GFRP bars and the other with steel bars, were tested by following an existing procedure in the literature. The test specimens, measuring 4750 × 2500 × 195 mm, include under-rail pads as well. The testing procedure involved both static and fatigue tests, with specific limits set for maximum system displacement and stiffness variation. During the fatigue tests, each rail of the specimens was subjected to three million loading cycles at a frequency of 7 Hz. The applied testing loads were determined based on the guidelines provided in UIC 713R [1] and EN 1992-1 [2]. Subsequently, the fatigue test data were utilized to estimate the fatigue life of each specimen. The results showed that the slab track reinforced with GFRP bars (STGB) exhibited a 37 % longer fatigue life than the steel-reinforced specimen (STSB). Since the STGB met all testing requirements of the deployed testing procedure and demonstrated superior fatigue life, it provides a promising solution to mitigate electrical conductivity and corrosion issues while enhancing the overall life cycle performance of slab tracks.