System Performance of a Precast Bridge Incorporating Full-Depth Deck Panels and Prestressed Inverted Bulb-Tee Girders

Abstract

The South Dakota Department of Transportation (SDDOT) allows the use of precast, prestressed double-tee girder bridges in county and local roads because they are economical and fast in construction. However, many of double-tee bridges are deteriorating, and some need total replacement after 40 years of service. Furthermore, there is only one supplier of prestressed double-tee girders in South Dakota. The present study was carried out to investigate the feasibility and performance of an alternative precast bridge system for local roads incorporating precast full-depth deck panels and prestressed inverted bulb-tee girders. A full-scale bridge specimen consisting of two interior girders and five precast panels was tested under fatigue and strength loading. No significant damage beyond shrinkage cracks was observed through the entire fatigue testing, and the overall bridge stiffness did not change. The load at the first cracking was higher than the equivalent AASHTO Service and Strength I limit states under strength testing, indicating sufficient performance. Based on the construction, testing, and cost analysis, it can be concluded that the proposed precast bridge system is a viable alternative to double-tee girder bridges.