Wapello County and the Iowa Department of Transportation were granted funding through the TEA-21 Innovative Bridge Construction Program to demonstrate the use of ultra high performance concrete (UHPC) in a bridge replacement project. The UHPC in the prestressed concrete beams is expected to achieve a 28-day compressive strength of up to 30,000 psi. The use of this innovative product in a threebeam cross section is intended to take advantage of the superior strength and to optimize design. The beams will be pretensioned using 0.6-inch diameter strands and without mild reinforcing steel, except to provide composite action with the cast-in-place deck. In Phase I of the multi-phase project, a 71-foot-long test beam will be tested to verify shear and flexural capacities, along with shear testing of smaller beams. If testing efforts are successful, Phase II will include the casting of 111-foot-long beams, followed by the construction of the single span bridge in the spring/summer of 2005. After construction, a monitoring program will be implemented to document the performance of this innovative product. A discussion of the design efforts and the current progress of this research project is the focus of this paper.
Abstract