| Ground
Penetrating Radar (GPR) is a nondestructive technique which utilizes electromagnetic
energy to locate objects or interfaces within a material. The radar unit
detects back scattered radiation that is reflected at the boundary between
differing dielectric media. By measuring the time it takes to receive the
reflected signal, the depth of the embedded object or interface may be
determined.
The system
utilizes a high frequency dipole antenna to transmit a train of discrete
amplitude modulation (AM) radio wave pulses. A second antenna, housed next
to the transmitting antenna, is used to receive the scattered pulses as
they return to the surface of the material. The output is fed to sampling
circuitry before being digitally processed by a computer. A realtime visual
display of the material cross section is recorded as the antennae are moved
along the surface.
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Ground
Penetrating Radar is useful for rapid detection of embedded objects in
concrete, masonry, soil and other common materials used in civil engineering
applications. The unit is extremely portable and permits large areas to
be surveyed with minimal disruption to the area under investigation.
Typical
Applications of Ground Penetrating Radar include:
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Locating post-tensioning
tendons and mild reinforcing steel in concrete slabs
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Locating embedded
conduit, pipes or other objects in concrete slabs
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Locating footings,
pipes or other objects below grade
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Finding grouted
cells and reinforcement in masonry
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Locating voids,
delaminations and honey-combing in concrete
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