Punching behaviour of composite bridge decks transversely prestressed with carbon fibre reinforced polymer tendons

Abstract

Composite bridge decks under concentrated wheel loading develop compressive membrane action that tends to increase significantly the strength of the deck slab. Transverse prestressing of the deck slab can improve the compressive membrane action and allow a reduction in the slab thickness. With a reduced thickness, however, durability is a concern with steel prestressing tendons. By using fibre reinforced polymer prestressing tendons, the durability of the bridge deck slab can be improved. This paper describes an experimental investigation to study the punching behaviour of composite bridge decks transversely prestressed with carbon fibre reinforced polymer (CFRP) tendons. Six panels of a 1/4.04-scale model of a simply supported composite bridge deck are tested under a static concentrated wheel loading. The results are compared to those from a previous similar study using steel prestressing tendons. It is shown that it is feasible to use CFRP tendons to transversely prestress composite bridge decks, and that the CFRP prestressed bridge deck shows better overall structural performance than the steel prestressed deck. The lack of plasticity of the CFRP tendons is not a concern in this application.Key words: composite bridge deck, concrete, compressive membrane action, punching shear, prestressing, advanced composite material (ACM), fibre reinforced polymer (FRP).