The structural optimisation of innovative materials requires reliable numerical modelling, which can predict the structural behaviour of the respective adaptation under possible scenarios. This paper presents the numerical modelling of macro synthetic fibre reinforced concrete (MSFRC) in railway sleeper applications. MSFRC is well known to improve post-peak flexural strength and toughness owing to the crack-bridging mechanism of fibres. Even though the fibres act individually along the crack interface, MSFRC depicts tension hardening as a material. Therefore, this paper highlights the integration of fibre-concrete composite action as a homogenous material towards efficient modelling of MSFRC in terms of computational resources required. The concrete damage plasticity model (CDP) being widely used to simulate the plain concrete behaviour, the adaptability of CDP in the numerical analysis of MSFRC was investigated using the experimental data. Since the railway sleeper is subjected to impacts caused by wheel-rail irregularities, the accountability of the CDP parameters under both static and low-velocity impacts was also evaluated. Correspondingly, the modified CDP parameters reasonably represented the static and impact capacity, crack and damage evolution, and structural stiffness of MSFRC sleepers.