22:21 Jan-05-2010 James Gauthier NDT Inspector, Operations Manager GE Inspection Services, USA, Joined Nov 2007 25
Concrete Inspection (8ft thick/access one side only)
I am familiar with GPR systems and technology as we have a couple of these units. Good for approx. 3 ft as a rule of thumb (dependent on concrete type and condition). My question is "does anyone know of a way to inspect an 8ft thick concrete specimen that you only have access to one side?"
Impact Echo systems come to mind but I am unfamiliar with the depth capabilities of that particular system. (I think it is similar to the GPR)
10:40 Jan-06-2010 Martin Schickert R & D, Institute for Materials Research and Testing, Germany, Joined Jan 2000 18
Re: Concrete Inspection (8ft thick/access one side only)In Reply to James Gauthier at 22:21 Jan-05-2010 (Opening).
The largest thicknesses measured non-destructively I have heard of were in the range of 1.5 to 2 m. We haven't done such measurements ourselves.
Success would depend strongly on the concrete and its surface conditions on both sides. Possible techniques would be ultrasound and impact-echo, using the best equipment and all filtering and averaging possibilities available. To be able to discriminate between back wall echoes and other reflections, I would use line scanning (B-scan) or planar scanning, possibly followed by SAFT reconstruction in the ultrasonic case.
I would be surprised if thickness measurements larger 2.5 m in conrete could be done. If somebody has achieved this, he might drop a note.