WHAT IS DIGITAL X-RAY Imaging?
Digital X-ray imaging produces a clear, accurate image of the features embedded in concrete.
Digital concrete x-ray imaging involves the non-destructive use of hard X-rays or gamma rays to image the interior of a concrete target to identify and locate rebar, conduit, post tension cables and other embedded objects. We capture images using an x-ray machine. We also capture images digitally, which increases productivity and safety compared to using film. Digitally rendering the X-ray image means that we can process and produce an accurate image of the subsurface in mere seconds, without the time-intensive lab processing necessary for film-based X-ray imaging.
We recommend using X-ray imaging when you need to:
- Definitively identify the location and type of hazard in concrete
- Inspect green concrete, as moisture makes GPR less effective
- Core or cut in a congested area
- Maintain operations without extended shutdowns
SAFETY AND EFFICIENCY
Digital X-ray imaging is safer and more efficient than film-based X-ray.
Cutting, coring, and breaking concrete can be dangerous, as the potential to strike subsurface features is high. Before commencing work, it is necessary to establish the location and type of embedded feature within the concrete surface. This allows your crew to safely and efficiently cut, core, or break concrete.
Penhall proudly offers industry-leading advancements in X-ray imaging with our digital X-ray solution. We employ radiographers who undergo specialized training and certification, and can perform digital X-ray imaging in a variety of settings. Due to our service industry, and our position as the nation’s leader in concrete solutions, our technicians are completely knowledgeable of common and not-so-common on-the-job hazards, and the safety procedures necessary to mitigate these hazards. Increase worksite safety with digital X-ray imaging and finish work without interruption or delay.
DIGITAL X-RAY VS GPR SCANNING
Digital X-ray produces a clear, definitive image of the subsurface, whereas ground penetrating radar (GPR) uses radio waves to produce a radargram, which shows subsurface undulations.
There are two ways in which to locate subsurface features within concrete: X-ray imaging or GPR. There are advantages and limitations to each process. At Penhall, we provide both services—we can work with you to determine the concrete scanning type most suitable for your project.
Digital X-ray imaging:
X-ray can be used in situations in which GPR is not effective, or when clear, definitive imaging is required. Highly congested slabs are ideally suited for the application of digital X-ray. Scanning concrete with X-ray can be performed on concrete of various thicknesses. Penhall’s digital X-ray technology acquires images immediately, allowing the radiographer to examine and mark the location and exact type of subsurface feature without the need to develop film at a lab.
Digital X-ray does require access to both sides of the concrete slab and is not suitable for scanning slab-on-grade concrete. Also, unlike GPR, digital X-ray cannot be used to determine the depth of subsurface features, only the location, size, and type.
GPR scanning:
Ground penetrating radar is also used to detect subsurface features, including rebar and rebar patterns, post-tension cables, and pipes and conduits. GPR can detect voids and deterioration within concrete, making the process ideal for avoiding potential structure collapse. GPR emits radio waves that travel through concrete and map the various undulations in the waves’ paths. This produces a radargram, which is interpreted to determine location, depth, and type of feature within the concrete. It does not require access to both sides of the concrete and can be used to scan slab-on-grade.
GPR cannot produce a clear, definitive image of the subsurface like digital X-ray imaging. The data GPR produces must be interpreted once scanning is complete in order to identify the types of features present in the slab.
| Feature | GPR | X-Ray |
|---|---|---|
| Radiation Exposure | NO | YES |
| Access to both sides? | NO | YES |
| Power required? | NO | YES |
| Restricted Area? | NO | YES |
| Resulting Image? | NO IMAGE | CLEAR IMAGE |
| Interpretation? | SUBJECTIVE | DEFINITIVE |
| Determine Size? | NO | YES |
| Determine Depth? | YES | NO |
Digital X-ray imaging vs GPR:
Digital X-ray and GPR both locate features within concrete. However, they accomplish this result differently.
X-ray can definitively identify the location and type of feature embedded in concrete because it produces a clear image. Because Penhall uses digital processing, the scanning process is safe and efficient. Digital X-ray is more specialized as it cannot be used to scan slab-on-grade concrete.
GPR does not produce images, but rather 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 slab-on-grade and other concrete that is only accessible from one side.
frequently asked questions
Film-based X-ray imaging requires processing images at a lab, which can take days. Digital X-ray imaging is different—images are created in real time as the concrete is scanned. We can produce a clear image of the subsurface in as little as five seconds using digital X-ray.
Concrete X-ray imaging does emit radiation. However, the radiation emitted using X-ray imaging is minimal and far below state-mandated levels. On top of this, Penhall X-ray operators are trained and certified, and wear the correct personal protective equipment when scanning. Digital X-ray is a safe way to scan concrete.
You should use digital X-ray imaging if:
- You have access to both sides of the concrete.
- You need an exact image of what lies within the concrete.
- You suspect the slab to be highly congested.
You should use GPR scanning if:
- You do not have access to both sides of the concrete (i.e. slab on grade).
- You can complete the job without exact images of what lies within concrete.
- You want a more cost-effective scanning method.