Construction and Testing of an Accelerated Bridge Construction Project in Boone County

New bridge systems are needed that will allow components to be fabricated off-site and transported to the bridge site for quick assembly with minimal disruption to the traveling public. Depending on the specific site conditions, the use of prefabricated bridge systems can minimize traffic disruption, improve work zone safety, reduce the impact on the environment, improve constructability, increase quality, and lower life-cycle costs. This technology is applicable and needed for both the rehabilitation of existing bridges and the construction of new bridges. The Federal Highway Administration (FHWA) has recently developed a program to promote accelerated construction through the use of precast bridge elements. This paper will present the construction process, construction schedule, and laboratory testing for one of the first applications of an accelerated bridge project utilizing precast components in the state of Iowa. Through the FHWA Innovative Bridge Research and Construction program, a bridge in Boone County, Iowa was constructed using several different precast, high-performance concrete elements. Researchers from Iowa State University performed laboratory testing on the precast components that were used in the Boone County bridge. Field instrumentation and testing was used to verify the post-tensioning operation and to verify several of the construction methods. The laboratory portion of this investigation was funded by the Iowa Department of Transportation (Iowa DOT) and the Iowa Highway Research Board. Also, a comparison of the actual construction schedule with a theoretical schedule was completed. A discussion of the laboratory testing, structural instrumentation, monitoring, and scheduling of this innovative bridge is presented in this paper.