SOLUTION

In 2019, WJE performed visual and sounding assessments, rebar cover surveys with ground penetrating radar (GPR), corrosion potential testing, and laboratory testing of concrete core samples for the concrete piers and abutments. WJE engineers found that the piers and abutments were in fair condition, but exhibited minor to moderate distress from chloride-induced corrosion of the steel reinforcement. Leakage through deck joints was identified as the likely cause of corrosion. The 2020 assessment included visual and sounding assessments, rebar cover surveys (GPR), overlay bond testing, and laboratory testing of concrete core samples for the bridge deck and superstructure. A service life evaluation of the bridge deck was also performed using WJE’s in-house modeling program (WJE CASLETM).

The WJE team found the bridge deck to be in good condition with limited distress, and estimated an additional fifty years of service life remained before damage would warrant rehabilitation of the deck. Two deck joint seals had failed, resulting in leakage as the primary cause of observed substructure and superstructure distress, including extensive corrosion damage to diaphragm beams and girder ends below these joints. This deterioration—not deck deterioration—will control the expected service life of the bridge. WJE provided the City with conceptual rehabilitation options that included conventional concrete repairs, joint seal repairs, and corrosion mitigation strategies. WJE also assisted the City with budgeting by providing estimated costs for proposed rehabilitation strategies.