Concrete X-Ray vs. GPR: How to Choose the Right Approach?
Ground penetrating radar is a geophysical method for imaging the subsurface. This method uses electromagnetic pulse signal to detect subsurface objects, voids or cracks.
GPR structural investigation is widely used by local government authorities, civil engineering, petroleum industries, landscaping and irrigation contractors, railway authorities, road authorities etc.
On the other hand, concrete x-ray gives benefit to any type of project that needs cutting, coring or drilling into concrete structures. This process is used to scan structural steel, post tension cables, live electrical wiring, heating lines etc.
How to Compare?
Both of these two processes have some advantages and some disadvantages. But one is considered to be the more practical means of scanning concrete. Here are some points of comparison between the two approaches:
1. Quality of Image:
In terms of quality, concrete ground X-ray provides a better result. The precise quality of an x-ray scan finds out the contents of a concrete slab.
Although GPR technology gets much closer but both approaches have their limits. Concrete x-ray can’t penetrate the slab thicker than 19 inches.
GPR image can be adjusted to penetrate the deep end of the slab, the image quality drops significantly.
Ground Penetrating Radar is more cost-effective. The main reason behind that is Concrete and structural x-ray requires scans of both sides of the concrete slab for proper imaging, whereas GPR only needs access to one side of the slab.
For that reason, slabs-on-grade cannot be scanned with X-ray but they’re routine and perfect for GPR.
GPR requires almost no set-up time. No costly off-site data processing is needed with GPR. Information is provided immediately and marked on the slab. This allows clients to do their work without delay, making the process cost-efficient.
An X-ray process uses a highly radioactive isotope cobalt-60. This requires extra precautions and the technicians need to go through rigorous training sessions before using this.
An X-ray scanning can take more than 5 hours. Yes, this is true that in areas with high electromagnetic activity, GPR scan results are skewed and unusable.
If there are many objects in a concrete slab, finding the right path for cutting becomes harder with this poor image quality, but in most of the cases, Ground Penetrating Radar gives perfect result.
GPR also gives on-site, on-screen imaging which X-ray does not. GPR unit is equipped with an odometer which enables the technician to back up over a target for another look and evaluation in real-time.
X-ray generates harmful radio waves, GPR is free from that. So there is no potential danger to the technicians or the clients with GPR.
Also, no designated safe area is necessary with GPR but a clear zone of around 100 feet in all directions away from the work area is needed for X-ray.
Ground Penetrating Radar provides a safer, cost-effective, more versatile option for concrete scanning than X-ray. GPR (Ground Penetrating Radar) is the concrete scanning technology of the future – the versatility outweighs the quickly reducing shortcomings of the image quality. Concrete x-ray is still not out of the market. When the image quality has to be perfect because of safety precautions or otherwise, the X-Ray is the only option.
Jon Armstrong is an expert in GPR and ground X-Ray techniques. He uses electromagnetic techniques in GPR structural investigation for great results. With many years of experience, he has excelled in these services.