NDT and GPR devices may be used to measure the thickness of concrete elements or the depth of embedded objects such as reinforcing or services.

Like with any Concrete NDT test the operator will need to choose the right device, with suitable range and penetration to measure the concrete element they are interested in.

What test methods are suitable for Slab Thickness Measurement?

Dedicated instruments like Olson Instruments' Concrete Thickness Gauge use Impact Echo testing. Ultrasonic Pulse Echo devices have similar capabilities and depth limits.

Ground Penetrating Radar is not a dedicated Concrete Thickness test, but within its maximum range of roughly 600 mm an operator may usually see the concrete slab thickness and details and record them as part of the scan.

PM8000 Cover Meter

Since the early 1970s, Proceq have been developing rebar locators and concrete cover meters. The result is the Profometer PM8000, the world's most compact, versatile and precise cover meter and the best Profometer yet!

durAbar Borehole Probe Cover Meter

The durAbar Cover Meter is used to detect reinforcing bars near to a hole drilled into a concrete structure. The system is a handheld battery powered unit with a 10 mm diameter probe.

Concrete Thickness Gauge 2

Verify Concrete Slab Thickness & Integrity No Coring — No Drilling — No Excavating

Pundit PI8000 - Pile Integrity & Impact Echo

The Pundit PI8000 is a combined Sonic Echo pile integrity and impact echo test system.

Pundit PD8050 - Ultrasonic Pulse Echo

Consolidated power in a single device for structural imaging, object and defect detection with ultrasound pulse echo Real-time imaging, weight optimisation and AI assistance Large scale 2D, 3D, heat map and AR visualisation modes Superior image clarity with control of all transmission parameters

GP8000 - Concrete GPR

The GP8000 is a portable concrete GPR radar. Faster, easier concrete inspections and structural imaging with SFCW ground penetrating radar technology.

GP8100 - Concrete GPR Array

Proceq's GP8100 is a highly productive portable concrete GPR array, built for fast scanning of large areas and to quickly locate objects in concrete structures.

GP8800 - Compact Concrete GPR

The Proceq GP8800 is a ultracompact, wireless, ground penetrating radar (GPR) system for concrete. It is used as a concrete scanner to locate rebar, post tensioning, embedded conduits and other embedded objects, with the ability to fit into tighter places than other GPR.

GS9000 - Subsurface Mapping GPR Array

The most efficient multichannel GPR system with real-time 3D visualization, interchangeable GPR arrays cover structure or underground mapping applications.

How to Determine Concrete Thickness with Sonic Testing?

When using Impact Echo or Ultrasonic Pulse Echo devices to measure concrete thickness, the quality of the measurement is controlled by choosing a suitable speed of sound in concrete, the velocity in m/s.

  • Confirm your testing system is in good condition and working as expected
  • Calibrate Velocity
    • Method 1: Ground Truithing
      • By taking a physical slab thickness measurement from an accessible region of the concrete element, the operator can set the velocity precisely to repeat the same measurement with the testing device. Precision of this methods can be as good as ± 2% of the measured distance.
    • Method 2: Use a reasonable velocity.
      • The approximate speed of sound in concrete is between 3500 to 4500 m/s in typical concrete mixes. This would introduce at least a variability of ± 15% if the assumed speed of sound is reasonable for the material under test.
    • Complete multiple measurements in a regions of similar geometry and take the average.