Infrasense has recently performed a condition evaluation of the bridge deck carrying Main Street over the Chemung River in Elmira, New York. The evaluation was carried out using infrared thermography (IR), ground penetrating radar (GPR), and high-resolution video (HRV) imaging.
The Infrared Thermography (IR) survey was performed according to ASTM D 4788 – 03 (2013) using the latest technology mounted to an elevated platform on top of the survey vehicle and operated remotely from within the vehicle. Data was collected with maximum temperature differentials caused by delamination.
The IR and HRV input was compiled in a series of passes across the roadway area of the deck, moving at approximately 30 mph. The Main Street deck required two passes - one for each lane. Each pass covered a deck width of 15 feet while the IR and HRV cameras were connected to an electronic distance measuring instrument (DMI) for accurate location referencing.
The GPR surveys were completed according to ASTM D 6087-08. The survey included 11 lines of data for the roadway area and 3 lines of data for the two shoulder areas; each representing a cross sectional slice of the deck at a particular offset. The DMI distance data was continuously recorded into each GPR record, so that each GPR data scan had an associated distance.