The importance of concrete GPR scanning

Posted on: 9 June 2016

Notwithstanding the proven significance of locating electrical lines and metal targets prior to cutting or drilling into concrete, you still hear stories about accidents that occur when the required reconnaissance is ignored. This article explains why concrete contractors should first identify hidden or buried obstructions in concrete through ground penetrating radar before proceeding with drilling or cutting operations.

GPR scanning                  

Non-destructive testing techniques are hugely preferred for identifying embedded electrical lines or metal targets in existing buildings. A while back, X-ray technology was the leading non-destructive method used to identify hidden targets in concrete structures. Over time, concrete GPR scanning has bettered X-ray technology. It's now considered the most effective technology when attempting to detect post-tension cables, rebar, or electrical lines in concrete before the start of concrete cutting or drilling. Concrete GPR scanning allows contractors to work quickly, competently and precisely in real-time. With GPR technology, there's no need to vacate the job site as targets can be located much more safely. Moreover, GPR equipment is reasonably priced and very easy to use in comparison to X-ray technology which is rather expensive.

What's at stake in locating what's underneath the concrete surface?

If hidden or buried obstructions are damaged during concrete drilling or cutting, the consequences can be devastating-from worker hazards, project delays, to cost overruns. Cutting rebar that is reinforcing the slab steel would obviously cause damage and even the structure to collapse.

Consider the following example. At a certain site, what should have been a straightforward project to cap a hospital sanitary line, a concrete contractor used a jackhammer to knock down the wall in order to cap the line. Unluckily, an electrical closet was on the opposite side of the wall. As a result, the electrical conduits contained in the closet were all damaged. The hospital was forced to switch off the power and make special arrangements before power to the hospital was restored. In this scenario, the concrete contractor did not scan the area before tearing down the wall. With the use of GPR technology, they would have detected the electrical closet on the other side.

Whether it's a post-tension cable or an electrical conduit in a concrete slab, or a hidden utility underground, it would be foolhardy for any contractor to continue with drilling or cutting operations without initially hiring the services of a professional GPR service provider. The risks involved with these types of operations are just quite a lot. For an affordable fee, those risks can be significantly reduced or even eliminated.