Load Testing of Prestressed Concrete Girder Bridges in Texas

There are numerous prestressed concrete girder bridges in Texas that fail to meet load rating criteria set forth by the American Association of State Highway and Transportation Officials (AASHTO). As such, they must be fully inspected and evaluated by personnel from the Texas Department of Transportation each year, rather than every two years, which is the standard inspection interval for public bridges. It is important to be certain that the true strength and performance of bridges that fail load rating criteria are not being underestimated by prescriptive load rating methods. Therefore, load testing of five bridges that fail load rating criteria as well as two bridges that pass was conducted in order to gain a more complete understanding of the actual condition and behavior of a sample of aging prestressed concrete girder bridges in Texas. The goals of load testing included a more accurate assessment of moment capacity, a better understanding and characterization of live load distribution, and ultimately, an assessment of the value of spending additional time and money on load testing.