Brand new construction projects typically require cutting and drilling existing concrete slabs. The slabs usually contain all kinds of elements including post-tension cables, different types of wiring, and even reinforcing bars. When you damage these things, it can cost a lot in potential repairs. Along with this, it can end up pushing a lot of delays on the project. It can even become a big safety problem for employees. All of this makes it very important to figure out what’s inside of the slabs of concrete before beginning the cutting process.
You need to scan the concrete with ground-penetrating radar. It’s one of the latest techniques for dealing with utility locations. This is something that comes with inherent benefits over the traditional method of using x-rays. That being said, this is a technique that does require professional training. It requires someone that knows and understands how to interpret the results of a GPR scan. You’ll find that there are scanning technicians that can respond relatively quickly to various service requests for these types of scans. This can be especially helpful if you figure out that you require the service late in the process.
What Are Some Advantages Of It?
One of the biggest drawbacks associated with using x-rays to find these types of underground utilities is the fact that you’ll need access to the different sides of the concrete. This is since a single side needs to receive the radioactive material whenever the film is positioned on the other side. This is a restriction that typically limits the use of x-rays to the more elevated slabs. GPR only is something that needs access to one of the sides of the concrete. Therefore, you are only able to use it for certain concrete where it was originally poured onto the ground in the first place.
GPR doesn’t identify the exact material that is found in the concrete itself. Therefore, you’ll find that technicians will need to use various other data points to figure out whether or not the internal structure is a conduit or rebar. This is a process that typically requires marking the location of the various anomalies and studying the various patterns to figure out what each mark means. For instance, if you have anomalies that are spaced around 12 to 18 inches away from one another, it’s likely a rebar. Whereas, anything that has more spacing between it is usually going to be post-tension cables. Any anomaly that is placed at an angle to the slab in question is typically conduits. This will depend on whether the images show any sort of banding or if they have a level of consistency.
GPR is a process that is also much quicker than traditional x-rays. This is especially true for larger areas. A standard scanning area is usually around a 2ft square. This is something that typically takes around 10 full minutes to both scan and mark. The overall accuracy in locating the position of the anomalies tends to be around 1/4 of an inch with good accuracy ranging from 85 to 90 percent for depth.
Embedded Electrical Services
This is essential when you are cutting into any type of concrete on commercial premises. Accurately detecting electrical conduits embedded is a must. Along with the potential repair costs, any damage to an underground utility is very likely to result in power outages and they can even pose safety risks to anyone near the site.
The procedure that is involved with detecting these types of conduits usually depends on whether or not the slab of concrete is elevated or if it’s on-grade. First, you need to inspect it and this requires detecting the embedded conduit before going ahead with any cutting or drilling. As it relates to slab-on-grade scanning, you’ll find technicians that are typically there trying to figure out the location where a trench can be cut for the installation of a water line or another type of utility.
Reinforcing Steel
As soon as technicians can locate the post-tension cables and rebar in any concrete with GPR, they are going to make the marks on the concrete itself. They will use the marks to ensure that the workers can effectively drive into the concrete without having to compromise its structural integrity. GPR scanning is something that can be very useful for helping to prep the site for a renovation. This is something that usually requires workers to cut into already existing concrete for new installations.
Voids
Any technicians will also need to be able to successfully locate voids. They will need to do this and it requires locating empty spaces in the sub-grade and grade that exist below the concrete. Voids are essentially the result of different forces that act on the ground. These can include soil erosion, pine ruptures, and even compaction. These are usually undetectable even from close visual inspection because they are fully converted by concrete and grade materials. GPR is something that can be advantageous at preventing workers from penetrating a void that can lead to a collapse.
Analysis
Concrete scanning is very important for being able to accurately analyze the contents of a specific structure. Not only does this include the thickness of the concrete material, but also information about the rebar including the spacing and depth of the concrete. The concrete analysis is something that has provided engineers with the information they need to effectively make good decisions regarding the concrete.
