What is it?
3D GPR is a non-destructive technique for pavement surveys to identify the thickness of the different paving layers, voids or areas of damage. This ground penetrating radar survey is completed at the appropriate speed to capture the level of data required for specific projects which reduces the time required for surveying the UK’s network.
3D GPR uses electromagnetic pulses which are transmitted into the pavement and receiving the reflections from the interfaces. 3D GPR can be used to determine pavement make up (depths/thickness of individual layers, construction changes) and detect services, voids and high moisture locations. 3D GPR surveys are achieved at appropriate speed to capture the level of data required for specific projects.
Why do it?
With an antenna width of 2.1m, 3D GPR covers a greater area. With 2 passes of the chosen highway we get a full coverage of the pavement. 3D GPR allows Engineers to interpret the data, identifying;
- Construction thicknesses and changes (bound and unbound layers)
- Defects (e.g cracking, high moisture content, debonding, voiding)
- Detect mid-lane longitudinal construction joints and concrete edge beam if present
- Presence of Services
- Control budget by limiting other works and road closures
PTS have demonstrated the benefits of full carriageway width 3D GPR on various schemes for clients such as Highways England, County Councils and Contractors, from small schemes to full network coverage projects. Our clients benefit from our services when requesting inspections of bridge decks and also specific moisture and void assessments.
If you have any queries or requests for GPR Surveying then please contact the lab and we will be happy to help.
Our GPR technology offers one of the best solutions for the mapping of rebars and detecting the thickness of concrete slabs. We provide an extensive range of rebar location services and we scan concrete structures to detect voids and discontinuities. We scan and report rebar information in 3-dimensions (X, Y, Z) and can deliver visual, vector, and CAD reporting formats.
The condition assessment of concrete bridge decks, as part of a scheduled maintenance programme, forms a key requirement for both transportation companies and local authorities. Traditional methods of assessment, for example hammer sounding and chain drag techniques, depend on the experience and proficiency of the inspector.
The application of Ground Penetrating Radar techniques offers an invaluable alternative due to the higher level of accuracy that can be achieved through this non-intrusive and highly cost-effective technology. GPR is used for detecting the reinforcements embedded in the concrete, the concrete slab thickness, and the asphalt layer thickness. The data can be interpreted and used to develop a corrosion map for the steel rebars, which in turn supports maintenance decisions.
The Benefits of GPR Surveys
- Data Collection at Traffic speed
- True 3-Dimensional data
- Optimal resolution at all depths
- Pavement – Delamination. Dowel Bar Alignment. Rebar
- Bridge Decks – Rebar health. Overlay. Delamination
- Voids – Sinkholes
- Utility mapping – Power cables. Pipes