Design of Buchanan County, Iowa, Bridge Using Ultra High-Performance Concrete and PI Girders

Buchanan County, Iowa, was granted funding through the TEA-21 Innovative Bridge Construction Program (IBRC), managed by the Federal Highway Administration (FHWA), to construct a highway bridge using an optimized PI girder section with ultra high performance concrete (UHPC). UHPC is a relatively new structural material that is marketed by Lafarge, Inc. under the name Ductal. The PI girder section was developed to optimize the amount of material used in a girder, since currently the cost is relatively expensive. The Buchanan County project will be the first time the PI section has been used for a highway bridge in the United States. The girders will be pretensioned longitudinally and the deck will be post-tensioned transversely.