Diagnostic Testing for Improved Load Rating of Reinforced Concrete Slab Bridges

There are a large number of reinforced concrete slab bridges in Texas that were constructed in the 1950s and 1960s. Although most of these bridges were designed for less than the current legal load, they are still in service and performing adequately. Currently the bridges in Texas are load rated based on a procedure similar to the original design procedure. These procedures are very conservative and result in low load ratings for slab bridges. In order to take advantage of this inherent conservatism, a method of determining a better estimate of the capacity of these bridges is needed.

This study addresses the possibility of load testing reinforced concrete slab bridges in order to verify that there is adequate capacity to increase the allowable loads. A typical slab bridge was field tested. The test procedures are discussed, and the measured results are presented and evaluated.