Ferroscan and GPR Rebar Mapping Surveys

Ferroscan and Ground Penetrating Radar (GPR) both offer an effective means of reinforcement detection and imaging within concrete. Sandberg can undertake detailed reinforced concrete investigation and rebar mapping using either Ferroscan or GPR. Which method is better? What are the differences?

Both enable detected rebar to be viewed in a longitudinal section or as ‘slices’ at different depths. The Ferroscan can provide estimates of rebar diameter, while GPR can provide slab and screed thickness.

Both Ferroscan and GPR data can be downloaded onto a personal computer for further analysis, interpretation and printed output using specialist software provided by the respective manufacturers.

To help you decide which method is more suitable for your specific requirements, we have produced the following table which offers a comparison between the Hilti PS200 Ferroscan and a GSSI SIR3000 GPR system used with a 1.5GHz antenna (based on the manufacturer’s specification and our experience). GPR also has the flexibility of being used with different frequency antennas so better resolution or extra depth can be achieved.

 FerroscanGPR
Maximum detection depth~120mm (20mm diam)
~180mm (36mm diam)
~450mm
Rebar diameter determinationYes *No
Rebar diameter range6 – 36mm5mm – steel beam
Number of rebar layers resolvedtypically 1**typically 2**
Metal detectedFerrous onlyYes
Plastic detectedNoYes
Voids detectedNoYes
Slab thickness determinedNoYes
Screed thickness determinedNoYes
Real-time rebar locationYesYes
Single line scanQuickscan up to 30mUp to ~350m
Rebar imaging600x600mm areaAny size

* Max depth of rebar = 60mm. In our experience the calculated rebar diameter is indicative.
** Depends on rebar spacing and depth.

For more information, contact our in-house expert:
Portrait photo of Ewa Krylowicz
Direct Tel: 020 7565 7056

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