It's a 'picosecond' and it is also the measurement of pulse duration in the application of Ground Penetrating Radar (GPR)
Developed in the 1970’s, alongside great discoveries inventions such as the Cellular Phone and the Apple Computer, Ground Penetrating Radar (GPR) made significant advances through that decade. Innovations made in impulse radar (also referred to as short-pulse radar) saw GPR being applied to locate the boundaries between soil types. Later with expanded applications due to advances in pulse durations, GPR results are now able to be measured in ‘picoseconds.’
Scan before you excavate/’break’ the surface:
GPR is considered as a very effective NDT (Non-Destructive Testing) method for investigating the existence ‘buried’ services and objects. Before any cutting, sawing or drilling ensues, scanning concrete with such a tool a GPR can help determine the location of steel reinforcement, post-tensioning cables, electrical cables and conduits, etc. This us, GPR assists with retro-fit design and prevents avoidable damage and costs. GPR can also detect voids in and below slabs, delaminations in the slab, and determine slab-thickness, this information assisting with the design of repairs.
The selection of GPR over other non-invasive tools:
When compared to X-Ray for example, some of the advantages of GPR include the fact that it is very portable, safe to use and provides accurate information in rapid time.
The GPR equipment is compact, light and very portable and can readily be transported with our experts to your project.
2. Safe to Use:
Aside from being non-intrusive, GPR is also safe to use, emitting no radiation nor creating any hazard to the operator nor any surrounding persons or objects. Unlike other procedures that can only be carried out by certified radiographers wearing critical personal protective equipment (PPE), with GPR, there are no such requirements or precautions necessary
Unlike many other tools that require off-site processing and the development of the collected data, GPR’s ‘real-time’ imaging provides immediate information to our clients and engineers. Scanning can, for example, be performed rapidly without significant disruption or delays to work operations or business activities. Additionally, GPR normally only requires access to only one side of the slab, thus saving significant set-up time and potential inconvenience.
4. Reliable and Accurate:
GPR provides real-time 3D images of the area being scanned, with information being received by the engineer within minutes for both metallic and non-metallic objects, concrete depths and thicknesses with accuracy that can be down to as little a few millimetres.
5. Cost Effective:
Budget is a critical aspect of project management. Typically, other concrete scanning technologies such as X-Ray, can cost 3 to 10 times more than scans with GPR.
Tullamarine Freeway Widening, Melbourne:
As part of the above $1.3 billion project, there was a need to strengthen the prestressed concrete beams on the Mickleham Road Bridge. The design required passing bolts through the beams, a critical requirement being to ensure that the bolt drill holes avoided the prestressing strands/conduits. Infracorr utilised specialist GPR equipment and aids to locate the strands so that the contractor could confidently drill the bolt holes. In excess of 8,000 holes were ultimately drilled, with not one prestressed cable being encountered in the process.
GPR could’ve helped:
Swan Bridge Widening, Melbourne
The design for the widening of the 70 year old Swan St Bridge over the Yarra River was based on information obtained from the original construction drawings. When the contractor commenced drilling into the bridge, steel reinforcement was encountered indicating that the old drawings were not truly representative of the actual construction. Infracorr utilised sophisticated GPR techniques to produce 3D models indicating the locations of the reinforcement, thus providing the contractor with the information needed to ensure critical reinforcement was not damaged during the drilling process.
Talk to us about how we use Ground Penetrating Radar to help you cut costs in investigating deterioration and concrete health.