A valued customer recently requested that we map out all post tension cables in an Orlando area resort. There were four areas, each about 500-1000 square feet, that needed to be mapped out, with both the post tension cables and the conduit marked. We were asked to paint the PT cables red and the conduit blue in order to distinguish between the two.
The customer had photos of the area prior to the concrete pour, so we were able to compare our field markings to photograph, and we thought the results were worth sharing. Not every job allows for such a stark visual confirmation of our findings, but in this case, the customer’s photo demonstrated the clarity and accuracy of our marks.
Note: There was a piece of conduit in the photograph that was not in our field markings. We confirmed that this conduit had, in fact, been removed prior to the pour.
The conduit was easy to distinguish from rebar in this particular slab because it was empty and thus created a negative reaction—the metal rebar reflects the GPR signal back to the receiver, whereas the air inside empty conduit does the opposite. Sometimes conduit is full of metal wiring, and in those cases, it may be more difficult to distinguish, and technician may rely more on context clues (e.g. breaks in patterns and spacing, depth of anomaly, line angle, etc.)
Our customer proceeded with the work on the above area without incident, and has since scheduled additional work at the site. Its jobs like these that build our confidence that we as a team are doing truly valuable work. The average construction budget spends only .1% on locating services, but those locating services have been found to produce a 6x to 8x average return in savings. And even beyond these numbers, locating services keep people safe and keep projects on schedule, which adds its own kind of value. We have a professional team with a strong track record in a field that is adding true value back into the construction industry and the economy as a whole. That is something we are proud of.
GPRS does not provide geophysical, geological, land surveying or engineering services. If you need such services, please contact an appropriate professional. If you are interested in hearing more about how GPRS can help you on your next project, please call us.