Improvement of Mechanical Properties of Railway Track Concrete Sleepers Using Steel Fibers: Fid-Bau Portal

Improvement of Mechanical Properties of Railway Track Concrete Sleepers Using Steel Fibers

Tolou Kian, Ali Reza

AbstractThere has been a significant increase in axle loads, speed, and traffic volumes in railway transport systems in recent years. This has stimulated improvements of track component characteristics from the aspects of stability, durability, and energy absorption. This research has focused on concrete sleepers as the main element of the track superstructure. It investigates the efficiency and practicability of using steel fibers in improvements of sleeper characteristics, including load-carrying capacity, energy absorption, and dynamic properties. This is done through a comprehensive experimental work. Extensive static and dynamic tests were carried out on the prestressed concrete sleepers designed and manufactured with various amounts of hybrid steel fibers (a mixture of short and long fibers) and different numbers of prestressing steel wires. The research results have indicated that the use of hybrid steel fibers in the sleepers leads to an increase in load-carrying capacity, energy absorption, and consequently improvements in the service life of the sleepers. The results have also indicated that the new sleepers have the same dynamic characteristics (natural frequency, damping ratio, and mode shapes) as the conventional ones. Considering the improvements made in the mechanical properties of the new sleepers and the resulting construction costs, it has been shown that the new sleepers are more effective and cost efficient for high-speed tracks when compared with the conventional ones.