Analysis of an Ultra-High Performance Concrete Two-Way Ribbed Bridge Deck Slab

Ultra-high performance concrete (UHPC) is a relatively new material which has demonstrated good durability properties, high compressive strength, and usable tensile resistance. Recent material characterization and structural behavior studies have shown the average compressive strength to be 28 ksi while a tensile strength of greater than 1.5 ksi can be maintained throughout a tensile strain of approximately 0.010. These desirable mechanical properties make UHPC a worthy material for use in our nation’s highly stressed bridge decks. Since UHPC exhibits a unique flexural behavior, a design methodology must be developed to distinguish it from traditional reinforced concrete behavior. This report details UHPC flexural behavior, presents a design methodology, and presents the analysis of a two-way ribbed precast bridge deck. With the absence of design specifications for UHPC, the 2006 AASHTO LRFD Bridge Design Specifications were used where appropriate in the design and analysis of the bridge deck. From the proposed design methodology, mechanics of materials, and strain compatibility, the UHPC deck cross section in this report is analyzed for positive and negative moment capacities. The analysis reveals the proposed UHPC deck design to be capable of resisting the developed design loads. Further verification through physical testing of a full-scale UHPC two-way ribbed deck slab is recommended.\n