Infrastruct AMS with a well-known civil engineering contractor recently completed a Phase 3 Post-Tensioned Special Inspection (PTSI) on a large three span bridge in the West of Ireland.

Combining the techniques of Ground Penetrating Radar (GPR), Impact Echo and Linear Polarisation Resistance (LPR) we were able to plot the post-tensioning duct profiles in each beam, non-destructively assess if voiding was present in the ducts and measure the rate of corrosion on the embedded reinforcing bars.

Duct and tendon exposures at selected locations confirmed the Impact Echo test results showing fully grouted sections as well as partially or fully voided sections in the ducts.

The pictures below show the marked-up duct profiles on the beams, the Impact Echo testing and a duct and tendon exposure in a fully voided section of post-tensioning duct.

For more information on any of the specialist testing described above or indeed any structural testing and investigations please contact Dr Thomas Callanan in Infrastruct Asset Management Services Limited.