Ground Penetrating Radar (GPR) is a non-destructive pavement survey technique for identifying the thickness of the different paving layers, voids, or areas of damage. This method of subsurface profiling uses electromagnetic pulses transmitted into the pavement, and when the pulse encounters a change in material properties (e.g. pavement layer, pipe, reinforcement bar, etc.) the energy bounces off the target and returns to a receiving antenna. This returning signal is recorded as single line scans, colour coded, and stacked to create a detailed subsurface profile.
Our 3D GPR multi-channel array, which operates at traffic-speed, overcoming the limitations and expense of more traditional methods, can determine pavement make up, thickness of individual layers, construction changes, services, voids, and high moisture locations. This survey technique delivers numerous and significant benefits for our clients by providing a greater understanding of the sub-surface make-up and condition of paved network assets, as well as providing a safer and more cost-effective survey methodology. We can support you with your projects from small schemes to full network coverage.
We also utilise the latest Proceq GPR Subsurface GS8000, which provides intuitive real-time visualization in 2D and 3D alongside superior data clarity. The GS8000 is a light weight and easy to use GPR device perfect for providing single line scans in remote locations where traffic-speed surveys are not possible.
GPR applications include:
- Pavement thickness measurement
- Subsurface void detection
- Evaluating pavement integrity
- Detection of reinforcement steel (rebar)
- Assessing subgrade conditions
- Locating underground utilities
- Foundation layer evaluation
- Monitoring pavement deterioration over time
- Filter drain assessments
- Bridge deck inspections
- Layer interface mapping
- Detecting water infiltration
Filter Drain GPR Applications
Filter drains are gravel filled trenches that collect and move water as well as treating pollution, and over time their ability to remove water from the pavement surface and surroundings degrades due to sediment contamination. Floating water brings blocking agents (e.g. small size particles, dust etc.) that fill existing voids within the filter drains medium (aggregate). The objective of filter drain surveys is to measure the extent and intensity of clogging within the filter medium in accordance with CS 551.
Our step-frequency Proceq GS8000 system is mounted to a lightweight trolley and is suitable for walked surveys of filter drains. It offers manoeuvrability, allowing precise survey lines to be followed. A visual survey will also be carried out on the filter drain to record the overall asset service level and the structural condition grading of the filter medium. Filter drains are graded based on the void ratio and structural condition, to allow targeted treatments where required.
Bridge Deck GPR Applications
The 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, such as hammer sounding and chain drag, rely heavily on inspector experience. GPR offers a non-intrusive, cost-effective alternative, delivering higher accuracy and more reliable results.
GPR detects embedded reinforcement, concrete slab thickness, and asphalt layer depth. The data can be used to create corrosion maps of steel rebars, supporting informed maintenance decisions.
Why choose XAIS-PTS?
At XAIS-PTS our team has a wealth of experience, and we deliver comprehensive pavement investigations across major infrastructure. We also deliver a wide variety of asset management surveys, software, professional services, programme development & design, materials testing, and certification services.
If you have any questions or queries about our services, please contact us today – our team will be more than happy to have a conversation with you regarding your project requirements!