Experimental characterization of ultrahigh-performance concrete bridge deck system

A lightweight, low-profile ultrahigh-performance concrete (UHPC) deck system reinforced with high-strength steel (HSS) has been proposed by the authors as an alternative to open grid steel deck. The system consists of a thin slab with primary ribs spanning between girders and shallower secondary ribs, parallel to the girders, connecting the primary ribs together. Earlier studies have shown the constructability of the deck. This paper presents system development of the deck, its connections to girders and adjacent deck panels, its response to repeated loading, and its lateral distribution of live loads. The deck-to-girder connection was made as cast-in-place UHPC around welded shear connectors and was designed to resist the shear from braking forces and the uplift from wind loads. The deck-to-deck connection was made as tongue and groove to transfer the load from one panel to the other as vehicles move on the bridge. The experiments presented in this paper confirm the feasibility of the proposed deck because the panels and their connections successfully endured 2 million cycles of repeated loading with a residual strength of at least 47% higher than the target load. Further studies are needed (1) to optimize the design by further decreasing the weight of the deck, (2) to assess the effectiveness of the UHPC as wearing surface, and (3) to monitor field performance of the deck under ambient traffic and designated truck load.