Enhancement of Bridge Decks Through the Use of UHPC Overlays

Bridge decks are susceptible to a variety of damages resulting from mechanisms such as freeze-thaw cycles, chemical attach from surface treatments, and mechanical stresses induced from dynamic vehicle loads. This damage is often exacerbated in "Salt States" where deicing chemicals are frequently used during the winter months, and are often the cause of premature deterioration of bridge deck. The primary function of a bridge deck overlay is to extend the life of the structure by providing an additional barrier for protection of the superstructure from contaminant penetration, but the overlay also serves to provide a durable wearing surface for traffic. For long-term performance, these overlays need to provide sufficient bearing capacity which is adequate for the loading on the bridge deck while remaining compatible with the existing bridge deck or substrate. These characteristics are fulfilled when the overlay concrete achieves optimal strength and resistance to crack propagation. The purpose of this research project is to explore a concept that may help to minimize the aforementioned bridge deck deterioration problems by evaluating the efficacy of using thin UHPC overlays on concrete bridge decks. The potential benefit of this type of solution is a more sustainable solution for both repairs and new bridge decks without significant deviation from current established practices.