Enhancing the resistance of prestressed concrete sleepers to multiple impacts using steel fibers

This paper investigates the effects of replacing cement with ground granulated blast furnace slag (GGBFS), adding hooked steel fibers, and reducing the number of prestressing strands on the behavior of prestressed concrete (PSC) sleepers subjected to multiple impacts. Five PSC sleepers with and without GGBFS and steel fibers were fabricated and tested using a drop-weight impact test machine. Test results indicate that the hammer weight and loading protocol strongly influenced the multiple impact resistance of PSC sleepers. In terms of peak reaction load, maximum deflection, and residual deflection, the multiple impact resistance of PSC sleepers was enhanced by including GGBFS and 0.75 vol% steel fibers and increasing the number of strands. The maximum crack width was reduced by increasing the number of strands and including steel fibers, and the steel fibers also effectively limited crack propagation, the number of cracks formed, and concrete spalling. Lastly, the flexural strength of PSC sleepers damaged by multiple impacts was improved by including steel fibers and more strands. Consequently, the overall performance of PSC sleepers subjected to multiple flexural impacts was improved by adding 0.75 vol% steel fibers and increasing the number of strands.