Applicability of synthetic fibre reinforced concrete for railway sleepers

Currently, the railway industry is forced to implement innovative sleeper materials due to the premature failure of conventional sleepers and the associated cost incurred in their replacement. Thus, fibre reinforced polymers, geopolymer concrete, and modified concrete are researched to replace the conventional timber, steel, and pre-stressed concrete materials in sleepers. However, the implementation of such innovative materials is limited due to lower mechanical properties, lack of knowledge on the long-term behaviour and higher initial cost. Despite the reduced lifespan of concrete due to cracking induced by dynamic impact loading, concrete is widely used as a sleeper material. To improve the crack resistance, the research herein investigates a feasible replacement for conventional concrete by utilising macro-synthetic fibre reinforcement in concrete. Macro-synthetic fibre reinforcement has facilitated major improvements in concrete ductility through the crack bridging. Therefore, understanding these crack-bridging mechanisms in the fibre-concrete matrix as well as the mechanical responses to dynamic loading is vital towards the implementation of fibres in railway sleepers. The crack bridging mechanism of the Macro-Synthetic Fibre Reinforced Concrete (MSFRC) depends on various fibre factors and the rate of the load application. Thus, the research herein presented is focused on studying the fundamental mechanical behaviour of MSFRC with varying fibre volume ratio, length, and load rates.