Condition assessment of bridge decks by complementary impact/echo and ground penetrating radar

The application of complementary impact, echo, and ground penetrating radar (GPR) for condition assessment of bridge decks is discussed. GPR based delamination detection on identification of deteriorated sections of the deck while the impact and echo technique detected delaminations as reflectors within the deck. The process involved the correlation of impact, echo, and GPR data from a limited section of the deck to help in defining a suitable deterioration threshold in the GPR data for the whole bridge deck, separating better structures from deteriorated sections. Various devices integrated ultrasonic seismic techniques and provided an automated data collection and analysis, detecting and assessing delaminations at various deterioration stages. A portable property analyzer that implemented impact and echo for delamination detection was also used along with an ultrasonic surface wave technique for velocity measurement in the bridge deck testing.