Infrasense recently performed a ground penetrating radar (GPR) survey of the bridge deck carrying Lafayette Road over the Soo Line and B.N. Railroad in St. Paul, Minnesota. The GPR data collection system included dual 2GHz horn antennas and a SIR-30 control unit manufactured by GSSI of Nashua, NH. This GPR survey was carried out at normal driving speeds, with no lane closure or disruption to traffic. The results of the survey will be facilitate planning future maintenance rehabilitation efforts.
The GPR data analysis was carried out according to ASTM D6087-08 using Infrasense's proprietary software, winDECARR. The analysis involves tracking the reinforcing steel and bottom deck reflections and calculating the concrete dielectric constant, rebar concrete cover, and concrete attenuation (loss of energy through deck). The results include quantities and maps of concrete deterioration and rebar-cover, and are provided in PDF and CADD compatible formats.