This paper presents the experimental and numerical analysis of a composite deck consisting of steel core, glass fiber reinforced polymer layer and a concrete slab. A finite element approach is proposed to predict the behavior of the composite deck. In order to demonstrate the efficiency of the composite deck, a reinforced concrete deck with identical ultimate load capacity is designed. The mechanical properties and geometrical configurations of constituent parts of composite deck are modified and the resultant effects are evaluated and discussed thoroughly. The results show that the proposed composite deck with a low thickness, low weight and suitable deformability is appropriate for prefabrication when compared to conventional deck with the same ultimate load capacity. The material properties can be modified to improve ultimate load capacity of the composite deck and the strength-to-weight ratio of the deck is increased by changing the steel material to aluminum. The ultimate load capacity is enhanced by changing the composite deck cross section