Post-tensioned concrete slabs have been used in construction for many years. In fact, it was all the way back in 1969 that the Federal Housing Administration endorsed the use of post-tensioning in concrete for home construction. Post-tensioned slabs have many benefits over slabs that are reinforced with rebar. Post-tensioned slabs can be thinner, with longer spans. They are also less susceptible to cracking than other concrete slabs.
One of the downsides of owning a structure with a post-tensioned concrete slab is that if you ever need to modify it, you need to proceed with extreme caution. Structural modifications often require that the concrete be disturbed. You might need to cut a trench in the slab to run new plumbing lines or conduit, for example. Before you disturb the concrete slab, you want to know exactly where those post-tensioned cables are, so you can avoid them.
Currently, the best way to locate embedded hazards in a concrete slab is by using ground penetrating radar (GPR). GPR technology allows a technician to safely and efficiently scan a concrete slab and provide you with the locations of all post-tensioned cables in the area you wish to disturb, as well as any other embedded items.
Why is this important? Well, severing a post-tensioned cable can result in some pretty disastrous consequences. No, the building probably won’t come crashing down immediately, but the slab’s load-bearing capacity will be compromised, and it will likely start to crack or delaminate. There is also the possibility of injury or even death to anyone who is unfortunate enough to be nearby when the cable is cut. Post-tensioned cables, when severed, can recoil right out of the concrete when the stored tension is released. If that cable were to hit a person, it would be bad—really bad.
You really don’t want to “roll the dice” and just hope that you avoid any post-tensioned cables when disturbing your concrete! Taking the time to have your concrete slab scanned with GPR will allow your contractor to proceed safely with your project.
Since the contractor you will be using to cut into your slab likely won’t have their own GPR equipment, they will need to call in a company like Enhanced Scanning for GPR scanning services.
When we come to a property to provide GPR scanning services, we will provide you or your contractor with all the information they need to avoid post-tensioned cables and any other hazards embedded in the concrete. We can mark directly on the concrete slab or provide you with a document that maps out where everything is located.
Don’t take any chances when it comes to post-tensioned cables! Contact Enhanced Scanning to inquire about our GPR scanning services or to schedule service.