GPR & x-ray concrete

[SperlingPE]

How good is ground penetrating radar? Can it detect reinforcing size?
Typical situation, CIP building with no drawings of information on reinforcing.
Is x-ray the better way to go to find reinforcing sizes?

 

[a2mfk]

GPR has been great for me, been using them a lot lately for location of filled cells and rebar in CMU and concrete. Pretty accurate, +/- a bar size, and I want to say location within 1-2". They can scan a lot of linear feet quickly. I found a local company that is reasonable in price and turn-around time (FL).

Just emailed them about a new job a couple hours ago for a project with elevated concrete slab and CMU walls, even though we have some old drawings, who knows how it actually was built?

 

[LittleWheels]

X-ray (betatron or gamma) needs good access to opposing sides of whatever you are investigating. GPR only needs single-side access.

 

[jerseyshore]

I've had bad success with a local GPR company, I was lucky if they found the locations of rebar in the slab, let alone being to tell the actual size, that seems like a pipe dream.

Hopefully you can find a better company that is more accurate in their testing.

 

[EdStainless]

I knew of an engineering Co that expanded their parking lot.
The made a very detailed map of the rebar and use different sizes and spacing.
When someone wanted to offer GPR services they had to first inspect the parking lot.
If they didn't get a specific score they were no allowed to quote.

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P.E. Metallurgy, consulting work welcomed