Concrete scanning is the use of ground penetrating radar and other equipment to detect materials or voids within a concrete slab. GPR does not produce images, but data that can be interpreted by a trained analyst, who will use the information to identify the location and type of feature within the concrete. GPR can be used to scan slabs-on-grade and other types of concrete that can only be accessed from one side. X-ray concrete scanning equipment can only scan one side of a structure, which makes GPR more suitable for scanning slab-level concrete structures.
Concrete scanning is a non-destructive method of concrete evaluation that uses ground penetrating radar, or GPR, to assess the integrity of the structure in place and locate embedded utilities before concrete cutting, coring, drilling, etc. In addition, you can perform concrete scanning tests on your own terms, without unnecessary cost or delay. GPR can help you perform quick scans of a large area with significant savings in time and labour costs compared to the X-ray concrete scanning procedure. X-ray concrete scanning has long been used in the construction industry because of its accuracy.
If scanning services are not contracted beforehand, it can be assumed that concrete scanning is simply an additional cost for a project. In some cases, X-rays are generally considered more accurate than GPR scanning, as there is less scope for interpretation of the results, including visualisation of the condition of rebar and areas of corrosion or other defects. It is a much slower process and usually needs to be carried out out of hours and the images produced will need to be developed off-site, unlike the instantaneous results that GPR scans can produce. GPR signals may be inhibited or bounced if the scanned slab has a significant water or moisture content.
By cutting concrete without scanning it first, there is a chance that you may encounter an underground object or hazard. You also do not have to evacuate a construction site for fear of exposing other workers to radiation, as would be the case with concrete x-ray scanners. Digital radiography requires access to both sides of the concrete slab and is not suitable for scanning the concrete of the slab. The data produced by the GPR must be interpreted once the scan has been completed to identify the types of features present in the slab.