Performance of Innovative Precast Concrete Sleepers Prestressed with Glass Fiber-Reinforced Polymer Reinforcing Bars

摘要

Replacing defective reinforced concrete railway sleepers has reportedly been urged by several businesses and maintenance agencies. The harsh environmental conditions, especially in North America, trigger material degradation and steel corrosion. Glass fiber-reinforced polymer (GFRP) bars have been increasingly used in a wide variety of applications. The present study presents an original, promising application of GFRP as prestressed reinforcement in concrete railway sleepers. For prestressed GFRP sleepers to be accepted as replacements for defective sleepers made with timber and concrete, they must pass several short- and long-term tests. Full-scale GFRP- and steel-reinforced concrete sleepers were designed, tested, and compared according to the requirements of the American Railway Engineering and Maintenance-of-Way Association (AREMA). The test results show that GFRP- and steel-reinforced concrete sleepers achieved similar cracking levels and ultimate loads in the rail-seat negative and positive tests. The tested GFRP specimens met AREMA s requirements for static and fatigue loading for use in freight and commuter rail systems with the designated loads, spacings, and train speed used in this study. The failure of the prestressed GFRP-RC sleepers was governed by shear-compression failure, while the prestressed steel-RC sleepers failed by crushing of the concrete due to the slippage of steel strands. Moreover, field inspection of GFRP-reinforced concrete sleepers after 3 years under actual service conditions reveal very competitive performance and no cracks. Lastly, the results of this study constitute a basic step toward establishing code provisions for using GFRP bars as prestressing reinforcement in concrete sleepers for railway applications.