Method 08
Concrete scanning in Abu Dhabi, Dubai & Al Ain
Ground penetrating radar survey of slabs, walls and beams. Reinforcement, post-tension cables, conduit and voids located and marked on the surface before anything is cut.
What it is
When to specify concrete scanning
A slab is never just concrete. Reinforcement, post-tension cables, electrical conduit, chilled water lines and drainage all run through it, and a drawing issued years ago is not evidence of where any of them sit today. Ground penetrating radar is how you find out before a blade goes in rather than afterwards.
GPR sends a radar pulse into the concrete and reads what comes back. Changes in material density show as reflections, which is why it detects both metallic and non-metallic objects, unlike a simple cover meter that only picks up steel. Plastic conduit, voids and honeycombing all show up, and so do post-tension cables.
We scan the cut zone, mark every finding directly on the surface in survey paint, and issue a plan with depths noted. If the proposed cut conflicts with something, you know before mobilisation and can move the cut or refer it back to the engineer. Scanning is included in the price of any structural cut we carry out, and is also available as a standalone survey.
Applications
What we use it for
Pre-cut surveys
Scanning ahead of core drilling, wall sawing and floor sawing so cut positions clear reinforcement and services.
Post-tension cable location
Locating and marking PT tendons in suspended slabs and beams, where cutting one is both dangerous and expensive.
Rebar mapping and cover survey
Bar positions, spacing and cover depth recorded for structural assessment or remedial design.
Buried service location
Conduit, drainage and chilled water lines traced through slabs and walls before penetrations are formed.
Void and defect detection
Honeycombing, delamination and voids identified in structural elements during condition surveys.
Anchor point verification
Confirming fixings can be installed at the designed positions without hitting reinforcement.
Sequence
How the job runs
Define the zone
Cut positions or survey area agreed from your drawing and confirmed physically on site.
Grid and scan
Surface gridded and scanned in both directions so the reinforcement mat and any services are fully mapped.
Mark on the surface
Findings marked directly on the concrete in survey paint, with depths written alongside.
Issue the plan
Marked-up drawing or annotated photograph issued before we leave, with conflicts flagged in writing.
Site control
What scanning cannot tell you
Being honest about limitations is more useful than overselling the equipment. GPR is very good at locating objects and very good at depth, but it does not identify what an object is with certainty. A radar reflection tells you something dense sits at a given depth; whether it is a conduit or a drainage pipe is inference.
Detection depth also varies with the substrate. Dense, heavily reinforced concrete attenuates the signal faster than a lightly reinforced slab, and a congested top mat can mask what sits beneath it. Wet concrete and some aggregates reduce range further.
Where a finding is critical and ambiguous, the correct answer is a small inspection core to confirm visually rather than a confident guess. We will tell you when we think that is warranted instead of signing off a survey we are not sure about.
Questions