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Applications
Concrete scanning and imaging
Before anybody cores, cuts or drills. Rebar, post-tension tendons, conduit and slab thickness located and marked on the surface, with the crew standing there waiting.
The one that cannot be got wrong
Cutting a post-tension tendon releases stored energy violently and can compromise a structural bay. Drilling through a conduit is an electrical incident. Coring through a top mat weakens the slab exactly where somebody is about to load it.
This is the work where the margin for error is smallest and the cost of a mistake is measured in days of a stopped site, not in the price of the scan. It is also the work most often commissioned at the last minute, which we plan for rather than complain about.
How it is done properly
High-frequency GPR antennas — 1.6 to 2.6 GHz — give millimeter resolution through roughly the top 18 in of concrete. On anything that matters we collect a grid, not two crossing lines, because a tendon that drapes between the passes is a tendon nobody saw.
Targets are marked on the slab in the orientation and depth they actually occupy, and clear core positions are ringed — a positive instruction, not just a set of hazards to avoid. Where nothing safe exists within the requested location we say so on site rather than in a report that arrives after the hole is cut.
What it resolves
- Reinforcement — top and bottom mats, bar spacing, cover depth.
- Post-tension tendons, including drape through the span.
- Conduit and embedded services in slabs, walls and columns.
- Slab thickness and the presence of a second pour.
- Voids and loss of support beneath slab-on-grade.
- Underfloor heating, often better resolved with thermography than with radar.
Limits, stated before we start
A densely reinforced top mat shields what is beneath it — the first layer of steel can mask a second. Wet slabs and some lightweight and high-moisture concretes attenuate badly. Where the answer has to be certain and radar cannot give it, the honest advice is a small inspection opening, and we will give that advice rather than sell another pass.
Equipment and capability
- 1.6 – 2.6 GHz concrete antennas
- Grid collection, not crossing lines
- On-slab marking and ringed clear core positions
- Slab thickness and second-pour detection
- Void and loss-of-support detection beneath slab
- Rapid mobilization for stopped works
What you receive
Marked on the slab immediately, and where required a photographic record with the marked surface against the radar data, so there is a defensible record of what was cleared and what was not.
Ask before you commission
Tell us the target, the ground and the constraint and we will say whether this method answers it, whether it needs a second method alongside, or whether something else entirely is the better route. That conversation is free and it is usually short.