Infrastruct was part of an engineering team that carried out a range of structural testing and investigations on reinforced concrete track slabs in a tunnel in Scotland.

Infrastruct used combination of non-destructive testing systems on this project to investigate the integrity of two separate sections of track slab.

The non-destructive testing systems used by Infrastruct to locate and target weaker areas or to locate areas with structural changes in the track slab were as follows:

  1. s’MASH Impulse Response to survey on the top surface of the concrete track slab. This testing was completed in a grid pattern on the top surface of the track slab to rapidly identify suspect areas for further investigations using other testing systems. In total, there were 328 s’MASH test points recorded and analysed.
  2. MIRA Pulse Echo Tomography on the top surface of the concrete track slab to graphically examine the concrete integrity in the suspect areas of the track slab.  Selected areas on the slab were scanned using the MIRA pulse echo system to determine if major voids or anomalies were present within or beneath the track slab.
  3. Impact Echo (Olsen CTG-2D) to survey the selected locations and map the changes in the slab thickness.
  4. Ground Penetrating Radar (GPR) to survey the slab using a 1GHz antenna on the top surface and locate embedded reinforcement and other services.

The combination of s’MASH Impulse Response, MIRA Pulse Echo Tomography, CTG-2D Impact Echo and GPR proved successful on this project in determining the defects under the track slab.

The results of the non-destructive testing were recorded on-site by our Engineers and a comprehensive report, with interpretation was prepared for our Client.

For more information on non-destructive testing on structures, please contact Dr Thomas Callanan in Infrastruct Asset Management Services Limited.