Ground penetrating radar (GPR) uses radar pulses to determine if there are objects located under the surface. It can be used on dirt, stone, concrete, wood, and other materials. An object of a different density in the ground or in concrete acts as a reflector and returns a different signal that its surroundings. In addition to detecting hidden objects, such as tanks, pipes, and utility lines, GPR can show changes in material, voids, cracks, and the thickness of walls, floors, slabs, and other layers.
This makes GPR really useful for its traditional purposes: locating underground pipes and tanks, voids and sinkholes, and different types of materials. GPR can be used on soil, rock, pavement, and concrete, as well as ice, snow, or even water. In addition to mechanical integrity and non-destructive testing, GPR is useful for archaeologists, law enforcement, the military, and other groups. It has even been used on the moon. Things that are placed at regular intervals, such as rebar or concrete piles, can be easy to identify.
Technicians are trained to look for common patterns, and with experience will come to be able to quickly identify them. They can compare the location, shape, and length of the image to what is expected to be there, allowing them to develop an idea of what may have happened in the area.
At Encorus, we have used our GPR unit in traditional examinations, such as locating rebar within a concrete slab, pipes beneath a foundation, and utility lines underground. We have also been able to use it for some non-traditional projects, including locating a time capsule sealed within a building’s wall. If you have any questions, or would like a quote on GPR or any other mechanical integrity services, call Keith Taylor, Director of Mechanical Integrity Services at 716.592.3980 ext. 143, or email him at [email protected].