What you need to know about structural and GPR concrete scanning

Ground penetrating radar, or GPR, is a ground radar system used to scan below the surface without disrupting the ground itself. Our expert team use it regularly to detect structural elements, voids and defects within concrete and other structures.

This innovative form of concrete scanning has a number of uses:

  • Check for the presence of buried ground utilities before work begins.
  • Check for reinforcements in concrete and other solid ground coverings or structural elements.
  • Check for faults and flaws in newly laid solid floors before they are signed off.
  • In general, these applications of GPR scanning have a common goal to identify risks and allow you to account for them during any work you carry out, or to plan remedial work, to ensure safety and cut down on costs and disruption.

How does GPR scanning work?

As the name suggests, ground penetrating radar emits a radar signal into the ground and measures reflections back from physical objects beneath the surface.

Significantly, any physical barrier will reflect the signal back – unlike other methods of ground scanning, which are typically limited only to metallic objects.

GPR scanning can therefore locate all kinds of physical metallic and non-metallic obstacles, from electrics, fibre optics and telecoms cables, to water pipes, gas pipelines and sewers.

Our Proceq GPR Live ground penetrating radar features the unique Stepped-Frequency Continuous-Wave radar technology, which delivers the widest bandwidth in the market.

Benefits of GPR scanning

  • The advantages of GPR scanning are fairly obvious but they include:
  • Cost-effective as the ground does not need to be dug up to see what’s underneath.
  • Fast as large areas can be scanned and imaged before any physical work begins.
  • Non-destructive as the radar will not damage the surface or anything buried beneath.
  • You can combine GPR scanning with other methods, such as Hilti Ferroscan metallic detection, for an even more complete picture of metallic elements like reinforcing rebar inside solid concrete walls and floors.

With accurate real-time results, this means you can avoid disturbing foundations and reinforcements, while also generating an image that you can overlay into your CAD designs for further careful planning.

What’s the frequency of GPR?

GPR emits high-frequency radio waves capable of penetrating the ground, and a normal range of GPR frequencies is from around 10 MHz to over 2.5 GHz.

The frequency used affects the results obtained. Higher frequencies give better resolution but poorer penetration, whereas lower frequencies can see deeper into the ground, but at less image detail.

Perry Testing can make sure to use the correct frequency of GPR equipment for your concrete scanning project, ensuring that we produce images with the clarity you need, without missing objects that are a little deeper into the ground.