GPR vs XRAY

 

Before you begin your next project and start drilling, cutting, coring, or sawing into concrete, it’s important to make sure that there is nothing embedded or hidden that could cause harm to workers or damage the infrastructure causing costly repairs.

Since taking a risk without a GPR scan or X-Ray is not an option, how do you decide which one to use? Let’s break down the advantages and disadvantages of each.

GROUND PENETRATING RADAR (GPR)

Pros:

  • Access to only one side of the slab or deck is needed
  • Process takes less time
  • Immediate results mapped out on slab or deck
  • When you need to find a quick, clear area to core or drill
  • Job site does not need to be shut down
  • Does not pose a hazard to people or objects–safer than a cell phone
  • Scan’s can penetrate deeper than X-Ray with proper antenna
  • Items mapped on slab are accurate to within 1/4″
  • Lower cost than X-Ray

Cons:

  • Scanned images can be more difficult to evaluate without a properly trained technician
  • Areas with strong electromagnetic signals can often times interfere with the GPR scan
  • Immediate results mapped out on slab or deck
  • In highly congested areas with minimal scan room, it can be harder to sort out what each image represents

X-RAY

Pros:

  • X-Ray provides a very accurate image which can be important in determining if the image is conduit or rebar
  • The interpretation isn’t subjective

Cons:

  • The X-Ray process uses cobalt-60, a highly radioactive isotope, introducing radiation hazards to your jobsite
  • Job site gets shut down during the X-Ray process
  • Special procedures must be followed to ensure everyone’s safety, including erecting radiation signs and barriers; policing the safety area during the X-Ray
  • Conduct work during off hours
  • Access to both sides of concrete is necessary
  • Slab thickness is limited to 20 inches
  • Results can take at least 6 hours just to reproduce and then items will still need to be mapped onto existing surface
  • Transferring items from X-Ray to slab often results in items being off by up to 2″
  • More expensive than GPR

CONCLUSION

Both GPR and X-Ray can provide useful information prior to cutting, coring, sawing, and drilling. The decision about which option to use often depends on the parameters set by the owner. However, if the owner allows the contractor a choice, with the properly trained Scan2Core GPR technician, X-Ray should almost never be used. The costs to use it on a given project coupled with the health risks and the possible mistakes that are often made when transferring items from the X-Ray negative the concrete deck or wall should steer any well informed contractor away from the use of X-Ray. With all of this in mind, give Scan2Core, Inc. a call today and let our GPR techs save you time and money on your current or future project(s).