GPRS Post-Tension Concrete Scan - Chicago, IL

“Time is a primary currency traded on any given construction project. At Ground Penetrating Radar Systems, our everyday efficiency in operations allows us to respond to the immediate needs of our customers, often within 24 hours or less.” (

A Chicago contractor was working on a project in the downtown area that required them to locate rebar and post-tension cables inside of a concrete slab. They wanted to core through the concrete so that they have a sleeve to run pipes and electrical wiring through the floor without cutting into post tension cables, which could cause the cable to snap and cause extreme damage to the floor, as well as potentially harming a worker in the area. The contractor hired Ground Penetrating Radar Systems (GPRS) to mark out the rebar, post-tension, and any other anomalies in the column. The scope of the project consisted of scanning 1 area on the 35th floor of the tower.

Using an SIR-3000, we were able to locate and draw out the path of the rebar and post-tension within the scan area, as well as give an approximate depth to them. The reinforcement was clearly marked out with a black sharpie to highlight its location and depth. All GPRS Project Managers are all OSHA certified and can operate within most work environments. Thanks to our service, the contractor was able to core through the concrete and avoid hitting the reinforcement inside of the slab.

Our state of the art GSSI GPR equipment can send radio signals into concrete that send back in real time data for onsite interpretation. The radio waves are safe for workplaces so there is no need for stoppage in work for floors below or around scan areas. The specific equipment that was utilized for this job was the GSSI 1600 MHz GPR Antenna. Using the antenna, we are able to scan concrete up to 14” thick, and see anomalies that larger antennas would miss. GPRS also uses the RD-8100 Locator to locate live power and radio frequency (RF) signals underground. We can also detect utilities in or under concrete via induction or conduction with an exposed or known surface utility line.

GPRS technicians are commonly called for scanning for reinforcement such as rebar, mesh, and post tension cables. We also scan for conduits and radiant heat tubes as well.

At GPRS safety is one our #1 priority, when saw cutting or drilling the last thing you or our technicians want, is to hit a surprise conduit in the slab. While you may think that there is nothing in the slab, there is an unfortunate number of clients that call because they were proven wrong. The price of one of our technicians is well worth the price compared to the costs of repairing a mishap later on.

If you have any questions about GPRS applications or would have a need for GPR, feel free to contact Parker Schings on his cell: (224) 422-7284 or through email: If you are outside the Chicago area, GPRS is nationwide so please visit the contact page to find your closest local Project Manager.