Evaluation of the Structural Behavior of Prestressed Concrete Bridge Girders under Diagnostic Load: A Test-Case Study

This study presents an evaluation of the structural behavior of prestressed concrete bridge
girders subjected to diagnostic loading through a detailed test-case investigation. The primary
objective is to assess the performance, load-carrying capacity, and serviceability
characteristics of prestressed girders under controlled loading conditions. Diagnostic load
testing was conducted on an existing bridge girder system to examine parameters such as
deflection, strain distribution, crack development, and stress response. Experimental
observations were compared with analytical predictions obtained from structural analysis
models to determine the accuracy and reliability of the bridge assessment. The study
highlights the effectiveness of diagnostic load testing as a non-destructive evaluation
technique for identifying structural deficiencies, validating design assumptions, and
estimating the remaining service life of bridge components. Results indicate that the
prestressed concrete girders exhibited satisfactory structural performance within permissible
limits, with measured responses closely matching theoretical values. Minor variations
observed between analytical and experimental results were attributed to material aging,
environmental exposure, and boundary condition uncertainties. The findings demonstrate that
diagnostic load testing can provide valuable insight into the in-service behavior of bridge
girders and support informed decisions regarding maintenance, rehabilitation, and safety
evaluation of bridge infrastructure.