Performance Characterization of Fiber-Reinforced Rubcrete Sleepers

Impact loads of a significant magnitude acting on railway sleepers during derailments can come from a variety of sources, e.g., wheel–rail irregularities, track misalignment, train derailment, and so on. During a derailment, railway sleepers may be subjected to extreme impact loads. Usually, the sleepers may be irreparably damaged and need to be replaced. Improvement in the impact resistance of sleepers can control the damage caused due to derailment due to enhanced strength and stability to mitigate the effects of impact loads. It has been pointed out that fiber-reinforced rubcrete obtained by either partially or fully replacing natural aggregates with tire rubber particles has significantly high resistance to impact compared with conventional concrete. Hence, using it in sleepers has the potential to reduce damage due to derailment. However, it is essential to ascertain the performance of fiber-reinforced rubcrete in prestressed concrete sleepers before putting them into practice. Hence, in this paper, the performance of fiber-reinforced rubcrete sleepers is evaluated. Crimped steel fibers and polypropylene fibers were used in the study. The tensile strength of steel fibers and polypropylene fibers used was 1,100 and 551 N/mm2, respectively. Studies were conducted to compare the response of the sleepers subjected to rail seat static, bending, and impact tests. It was found that the impact energy absorption of the prototype of steel fiber–reinforced rubcrete sleeper was enhanced by 101% (2.01 times) compared with that of the concrete sleeper. These results indicate that the integration of fiber-reinforced rubcrete sleepers can significantly enhance resistance to impact loads during derailments and normal rail operations. This, in turn, reduces the risk of sleeper damage and enhances the overall stability and safety of railway tracks. Reduction of damage to sleepers leads to reduction in maintenance costs and usage to fiber-reinforced rubcrete leads to elimination of 4 t of discarded crumb rubber and saves the utilization of 14 t of fine aggregates. Thus, using fiber-reinforced rubcrete brings a sense of sustainability to the usage of prestressed concrete railway sleepers.