By: Len Lafond
When done competently, structural scanning can help customers save time and expense. But if the ground penetrating radar process is incomplete, potential hazards and interferences in the slab can damage the infrastructure, cause worker injury, and have significant liability implications.
Unfortunately, not all ground penetrating radar services are equal in value. Before you dive in and start core drilling, cutting, or sawing concrete, it’s important to ensure that your structural scanning provider follows three key processes to get the job done right – the first time.
- Thorough visual examination of the site. A highly-trained technician should go into electrical rooms, fire arm control rooms, telecommunications closets, etc. to see what is going into the slab or what needs to go into the slab. This gives the technician a better understanding of the elements that could cause potential hazards or interference prior to drilling, cutting, or sawing.
- Use of high frequency impulse radar. All too often, ground penetrating radar providers go straight to this step and completely omit steps #1 and #3. A minimally-trained technician will use high and low frequency impulse radar and digital imaging software to try and locate embedded objects in concrete slabs or soil. If radar scanning is the only step taken, it’s highly likely that objects will be overlooked or misinterpreted.In addition to conducting a thorough visual examination and using conventional utility locating equipment, it’s imperative that the structural scanning technician receive comprehensive training from the manufacturer’s factory representatives, as well as in-house training from experienced technicians in three key areas: core drilling, radar scanning, and utility locating.It’s also important to consider the equipment that the ground penetrating radar service provider uses. High frequency antennas using advanced technology will provide better resolution, allowing the technician to see things more clearly. Lower frequency antennas have also evolved, making it possible to look deeper into soil to locate buried utilities outside of buildings.Advanced digital imaging software also enables technicians to assemble a fully-interpreted map and report of the structure under review so customers conducting an engineering study or a permanent record can have more comprehensive, detailed information.
- Use of conventional utility locating equipment. After the visual examination and ground penetrating radar scan is complete, an essential next step is to confirm the results and sorting out the signals. By using special equipment, such as electromagnetic flux detectors, magnetometers, etc., the technician can better interpret the signals and determine whether they are originating from electrical conduit pipes, reinforcing components (tension cables, etc.), or something else.
Proper scanning processes can also help customers prevent serious calamity during construction—and even after construction is complete.
For example, when our Grafscan team was brought in to assess the concrete slab that was meant to support a new second floor of a hospital in Canada, our three-step process revealed that the slab way too thin to do so. Had this not been detected, an entire second floor would have been built on a weak concrete foundation and would have likely collapsed during construction or sometime down the road. Fortunately, because highly-trained Grafscan professionals approached the scanning process step-by-step, the issue was detected early, and people’s health and life was protected.
So always remember, before you drill, saw, or cut, be sure you look, scan, and confirm.