Effect of post-peak flexural toughness on the residual performance of macro synthetic fibre reinforced concrete sleepers subjected to impact loading

Dynamic impact loading is one of the predominant causes of premature failure of concrete railway sleepers, demanding a fair portion of the railway budget. Therefore, macro synthetic fibre reinforced concrete (MSFRC) is suggested as an alternative owing to its improved post-peak flexural capacity, ductility and crack arresting properties. In such adaptation, the residual behaviour after dynamic impacts caused by wheel-rail irregularities governs the reusability and the life cycle of the sleepers. Correspondingly, the residual performance of impacted MSFRC sleepers was evaluated experimentally compared to conventional prestressed concrete sleepers. The residual behaviour of the sleepers was further supported by a series of material-scale flexural experiments. The fracture toughness of MSFRC increased with the crack-opening width because of the tension stiffening associated with fibre bridging. As a result, the residual capacity, stiffness, and toughness of MSFRC sleepers were higher than conventional sleepers, thereby improving their adaptability to the rail network.