High frequency GPR

Phase were recently called in to utilise their expertise in ground penetrating radar (GPR) at a water treatment site.  There was concern that some of the reinforced slabs that made up an above ground tank may be failing and so, to assist in their structural assessment, our client asked us to provide information on the rebar structure at key points around two tanks.

We undertook a high frequency GPR survey and also utilised a Ferroscan to obtain additional information on the approximate diameter of the rebars.

The survey was successfully able to identify the rebars and other structural features within the slabs, including several areas where reinforcement was unexpectedly missing or had slumped / been deformed.  Some information on rebar diamter was obtained but the values obtained by the ferroscan seemed quite variable and would need proving by intrusive investigation.