Structural Behavior of Waffle Bridge Deck Panels and Connections of Precast Ultra-High-Performance Concrete

The AASHTO strategic plan in 2005 identified extending the service life of bridges and accelerating bridge construction as two of the grand challenges in bridge engineering. Previous studies have shown that using a prefabricated full-depth precast concrete deck system not only accelerated the bridge deck rehabilitation process but also extended its service life with reduced user delays and lower life-cycle costs. The recent use of ultra-high-performance concrete (UHPC) in the United States for bridge applications has proved efficient and economical because of its superior structural and durability characteristics. On the basis of the advantages of UHPC and precast systems, a design for a full-depth UHPC waffle deck panel system was developed. A full-scale, single-span, 60-ft long by 33-ft wide prototype bridge with full-depth prefabricated UHPC waffle deck panels has been planned as a replacement bridge in Wapello County, Iowa. In support of this project, structural performance and constructability of the UHPC waffle deck system and its critical connections were studied through an experimental program at Iowa State University. Two prefabricated, full-depth, UHPC waffle deck panels were connected to two 24-ft long precast prestressed girders, and the system was tested under service, fatigue, and ultimate loads. On the basis of the test observations and results and the experience gained from fabrication of deck panels and casting of UHPC infill joints (transverse and longitudinal), the prefabricated UHPC waffle deck system concept was found to be a viable option to achieve the goals of the AASHTO strategic plan.