Rii has been providing NYSDOT with bridge deck evaluations since 2008 using GPR as the survey method.
Buffalo Skyway Bridge and Associated Ramps
Most recently, Rii conducted GPR surveys of the Buffalo Skyway bridge and its three associated on and off ramps totaling 379,244 square feet of deck area. The Buffalo Skyway is 100 feet over the Buffalo River and carries two lanes of eastbound traffic and two lanes of westbound traffic. The total length of the bridge is approximately 5,808 feet. The purpose of the project was to locate and map deterioration in the concrete deck and the ramps through the overlay wearing surface on the bridge. The data was collected in just five hours using the single-polarization methodology with two air-launched horn antennas (1000 MHz), mounted on booms while maintaining a travel speed of 30 miles per hour. Rii submitted final reports which described the data collected and provided a GPR data analysis predicting deterioration through a series of maps created from the GPR survey results.
Survey of 50 Bridge Decks
In addition, Rii surveyed the condition of 50 bridge decks in region 7. Rii used the single-polarization methodology to scan the driving lanes and shoulders of the decks at intervals of 2-inch longitudinally and 3-foot transversally for the entire length and width of the decks between the curbs. The single-polarization method using two antennas has the advantage of covering more deck surface in a single day. For instance, these 50 bridges were surveyed in fewer than 16 hours back in 2008. Rii submitted the report to the NYSDOT describing the condition of all 50 bridges. It included a scaled plan view of each bridge deck showing the location and size of the concrete deterioration. It also provided the total percentage of deterioration of the complete structure. The deterioration map of each structure was included in the report as well.