When you need to find out what is in the concrete without digging it up there are a few different options that you can use.
Two of the most popular methods include ground penetrating radar (GPR) and concrete x-ray. Both have their own strengths and weaknesses, but most of the time you are better to use GPR over concrete x-ray. Depending on your specific needs, the ease of use, lower cost and safer working conditions of GPR usually beat out the comprehensive but laborious scanning using concrete x-ray.
The energy waves that are used to generate the image for ground penetrating radar are quite a bit less harmful then using a concrete x-ray. The relative output of GPR is similar in power to that of a regular cell phone, whereas concrete x-rays often require an 80 foot clearance for safe scanning. There is also much more personal protection equipment that is required when using concrete x-rays to keep the technician and other workers safe in the working area. These added safety precautions often result in the temporary closure of the working area and any associated loss of productivity.
There is also a major advantage to GPR as it only usually requires access to one side of the concrete slab, where a concrete x-ray requires access to both sides for proper imaging. Both GPR and concrete x-ray don’t do particularly well with slabs on a grade or if the concrete is greater than 18 inches thick. A GPR image can be adjusted to penetrate deeper with a lower frequency but this will result in a loss of resolution that often produces an image that doesn’t satisfy the requirements.
The advantage that concrete x-ray does have over GPR is that when you compare the images after both processes have been completed the x-ray will produce a higher resolution image. This gap is getting smaller and smaller as the GPR technology increases but this slight edge hardly makes up for all of the safety concerns and other limitations that concrete x-ray presents.
The last comparative difference between these technologies, and for many firms the determining factor, is cost. GPR is consistently less expensive versus concrete-ray when you just look at imaging techniques. You also have to factor in loss of productivity which results from the evacuation of the work space and additional personal protection equipment that further increases the difference between GPR and concrete x-ray. The last cost benefit to GPR imaging over concrete x-ray imaging is related to the digital image and usability of the final image. The increased technological increase of GPR software allows for easier processing and manipulation of the digital image post-test.
If your firm requires a high resolution image and can deal with all of the extra costs and added time for safety precautions, than concrete x-ray is the imaging solution for you. But for the vast majority of people and companies using GPR technology will give you want you need for a much lower cost. Because of this GPR is the preferred choice of most municipalities and industry as it is more versatile and cost effective in almost every situation over concrete x-ray imaging.