Performance of Concrete Bridge Decks of Similar Construction and Environment, but Different Traffic Loads

Maintenance, rehabilitation, and replacement of reinforced concrete decks are the largest bridge component expenditures for most transportation agencies. Therefore, concrete bridge deck performance was identified as one of the key bridge performance issues in the Federal Highway Administration’s Long-Term Bridge Performance Program. To improve knowledge of bridge deck performance, high-quality quantitative performance data should be collected periodically through the use of complementary nondestructive evaluation (NDE) technologies, such as impact echo, ground penetrating radar, half-cell potential, ultrasonic surface waves, and electrical resistivity. This paper presents the condition change of a bridge deck in Virginia over a period of six years. The assessment covered corrosive environment and corrosion processes, concrete degradation, and deck delamination. Deterioration progression from periodic NDE surveys is illustrated qualitatively by condition maps and quantitatively by condition assessment numbers. The results demonstrate the ability of NDE technologies to capture and quantify the progression of deterioration. Strong agreement between different NDE technology results improves the confidence level of the condition assessment of the deck. The study also evaluated the similarities in performance of bridge decks of comparable age, similar construction, and similar environment, with different traffic loads. Multiple NDE technologies were used to assess two concrete decks of a similar design, construction, age, and environment, but with different traffic conditions. The complementary use of multiple NDE technologies identified corrosion as the primary cause of damage in both decks. The severity of deterioration differed at the time of the survey, which caused the estimated remaining life of the two decks to differ by about 10 percent.