Evaluating the Constructability of NUDECK Precast Concrete Deck Panels for Kearney Bypass Project

The first generation of precast concrete deck system, NUDECK, was implemented on the Skyline Bridge, Omaha, NE in 2004. The second generation of NUDECK system was developed to further simplify the system and improve its constructability and durability. The new generation consists of full-width full-depth precast concrete deck panels that are 12 ft long to minimize the number of deck panels and transverse joints, and consequently accelerate bridge construction. It also uses covered individual pockets and bundled shear connectors at 4 ft spacing to simplify panel and girder production and eliminate the need for deck overlay. Precast deck panels are pre-tensioned in transverse direction and post-tensioned in the longitudinal direction to enhance deck durability. Post-tensioning strands are placed underneath the deck panels (at the haunch area) to eliminate threading strands through ducts and grouting operations. The objective of this project is to investigate the constructability of the 2nd generation NUDECK system through full-scale testing of two key features: 1) using self-consolidating concrete (SCC) to fill the gap between precast concrete deck panels and bridge girders as well as covered deck pockets; and 2) using the proposed deviators and anchorage block in the end deck panels for post-tensioning the bridge deck. These investigations includes evaluating the pumpability/pouring of the developed SCC mixture in mockup and full-scale specimens. Sequence of pumping/pouring of SCC as well as its quality control and quality assurance procedures are also demonstrated. The investigations also include pullout testing of the deviators and pushoff testing of the anchorage block used for post-tensioning to evaluate their performance and refine their reinforcement details