An explosion near a building can cause catastrophic damage to the building’s external and internal structural frames, causing the collapse of the walls and even loss of life. Due to the threat from such extreme loading conditions, efforts have been made during the past three decades to study the behaviour of structural concrete subjected to blast loads and to develop methods of structural analysis to resist blast loads. This paper describes the Finite Element Analysis of RC slabs under blast loading using the predictive engineering software LS-DYNA. The prediction of damage characteristics and mechanisms of reinforced concrete slab exposed to blast loading is done by taking the experimental data from the literature. The reliability of the numerical analysis was modelled using K&C concrete model and are validated by comparing with the experimental results. Further, the parametric study is carried out with K&C concrete model by varying the thickness of the slab, scaled distance and concrete strength. It has been seen that the slab thickness and scaled distance play a major role in blast loading. The maximum deflection has been decreased by increasing the slab thickness and by increasing the scaled distance. But in case of increasing the strength of concrete, the slab shows a very small reduction in maximum deflection. Thus the variation of concrete strength is not an efficient way in case of blast loading. Further, the blast pressure interaction with the reinforced concrete (RC) slabs is investigated by understanding the multi-material Arbitrary Lagrangian Eulerian (ALE) formulation with the ConWep formulation. The above parametric study was carried out with ALE. The advantage and limitation of K&C concrete model are studied in case of concrete structural components subjected to blast loading. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.