Job site conditions:
This example involves the development of an office space in an existing concrete building.
Floor electrical boxes must be installed into the concrete. The boxes measure 10” x10”, and must be installed 6” in depth into the concrete slab measuring 10” in thickness.
The structural engineer has restricted the use of any diamond cutting tools to prevent cutting any of the rebar.
The contractor must use a concrete breaker to make the 10” x 10” holes, 6” deep. And when reinforcing bars are encountered, the holes need to be moved or enlarged.
The contractor quickly realized that this would take too long and that it would be difficult to properly anchor these electrical boxes in holes too large or deformed.
With a ground-penetrating radar, the reinforcement bars which were at less than 6” in depth were located and marked on the surface. The rebars which were lower than 6” in depth were marked in a different color. The contractor and architect were then able to choose areas where cutting with a diamond tipped drill bit without cutting the reinforcement bars was possible.
Furthermore,while being able to avoid cutting the reinforcement bars, holes 2” in diameter were possible to drill at the bottom of the openings. The work could therefor be completed in much less time.