Concrete Scanning with GPR

Ground Penetrating Radar is very useful for determining concrete integrity, utility and rebar location, and void detection beneath foundations or slabs. Fault structures, slip zones, seepage zones, cavities, and washouts are also found within dams using geophysical techniques such as GPR, resistivity, or seismic refraction surveys.

Equipment for GPR consists of two antennae (one to transmit and one to receive) contained in a single unit, a handheld data logger, and an instrument for measuring distance. The antennae are in contact with the ground and are typically pulled along the surface as measurements are taken.

Depth of exploration varies from 3 to 50 feet depending on the type of subsurface and frequency of the antenna. GPR works similarly to regular radar; however, the pulses of radio waves are transmitted into the subsurface rather than air. As the radio waves travel into the subsurface they are reflected and refracted by velocity contrasts within the soil or from buried objects.