A cost and structural strength comparative study of a 15m span single bridge: a case study of an RC T-slab deck and a steel-composite UB deck.

Abstract

With the continuous growth of infrastructure development, our study aimed at conducting a comprehensive cost comparison between composite bridge deck and reinforced concrete bridge deck. The selection of an optimal bridge deck system is of paramount importance to ensure cost effective construction. The main objective of this report is to provide a comparative assessment of the structural strength and cost of construction of a reinforced concrete T-slab bridge and a steel composite bridge for a 15m span simple bridge deck using Midas civil software (v2020) that will enable clear cut decision marking for bridge design engineers. To achieve our objectives, two bridges decks that’s the steel composite and RC T-deck were modelled in Midas (FEA software), analyzed and designed. The design was undertaken for the two decks having the same 15m span. Finite element analysis was performed on representative models of the two bridge decks, considering various load cases and combinations. From Midas Civil, a comprehensive study of the analysis and design results was done to ascertain the strength comparisons of the bridge decks. Deign reports for the different decks were used to draft technical drawings for costing. Bills of quantities were made for both decks and from these some conclusions were made as follows: In terms of cost, the T-bridge deck proved cheaper as compared to the steel composite deck for a 15m span with a margin of 26.6% less. The results showed that the steel composite bridge deck exhibited lower shear values and bending moments compared to the RC T-slab deck for similar loads which indicated lighter sections for the former. From the strength studies, it was observed that the steel composite had a more load carrying capacity compared to the T-slab deck.