Technical Bulletin
Ground Penetrating Radar for Concrete Scanning

INTRODUCTION

Delta Geophysics Inc. is committed to providing our clients with solutions to the critical problem of locating utilities and reinforcing bar within poured concrete slabs.  Ground Penetrating Radar (GPR) technology is typically the methodology of choice, and has replaced X-ray imaging because of health concerns and accessibility issues.  Concrete GPR can save on concrete cutting or coring time, provide a safe working environment for personnel, and minimize equipment and property damages. 

OVERVIEW

Concrete GPR is a non-destructive and non-invasive method, works fast, and is generally accepted as the industry standard for most concrete investigation.  Reliability is greatly improved when experienced personnel use a high-frequency GPR antenna with maximum band width.  Even then success is not assured and should not be taken for granted.  This is because concrete is not homogeneous, and slabs contain various objects such as rebar, metallic/non-metallic conduits, post-tension cables and other embedded and overlapping features.  As a result concrete GPR is subject to shadowing and signal attenuation effects that can degrade survey results.

Another difficulty in executing a floor scan is the size of the antenna.  The size of most GPR antennas block access to small areas like closets and corners of rooms. Delta’s GPR equipment includes the latest GSSI 2000 MHz “Palm Antenna”.

This is one of the newest instruments on the market and is capable of providing high-resolution data in corners and close to walls, significantly improving the thoroughness of a concrete scan.

Concrete mark-outs can never be fool-proof, and are a great example of where reliance on inaccurate information can be more harmful than having no information at all.  

Concrete GPR Applications:

  • Locate metallic/non-metallic conduits
  • Locate Rebar
  • Locate Post-Tension Cables
  • Locate Metal Studs
  • Locate Voids
  • Concrete Layer Thickness
  • Inspection of Walls, Floors and Columns
  • And More..

We feel the personal at Delta are especially sensitive to the risks inherent in drilling a finished slab, and have the knowledge and experience to communicate unique survey concerns to your project manager at the jobsite.   Please contact us to determine if Concrete GPR will work for you.