This may be a place to start. http://www.geosearches.com/pages/355846/index.htm
Have a good day
Gerald
Hi Brian,
Here's a couple of links that may be helpful:
This link is to the ASTM Standards related to corrosion and wear :
http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/MARKETINGCODES/CD1.htm?U+mystore+imoq3345
This link is related to the corrision of steel in concrete:
http://www.corrosionsource.com/discuss2/ubb/Forum18/HTML/000006.html
Southwest Research Institute (SwRI) has developed a sensor called a "magnetostrictive sensor" that has been demonstrated to find remote flaws in a wide range of components such as bridge cables, etc. and would probably be applicable to embedded rebar. I believe the instrument has moved from research to commercialization. Check the following info: http://www.swri.org/3pubs/brochure/d17/magneto/magneto.htm
The principle researcher, Dr. Kwun is an enthusiastic and helpful guy.
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Hi Bill,
I noticed during my brief search, that there are newer ways of *locating* the rebar in reinforced concrete with access to only one side, but didn't see any that could *evaluate* them for corrosion. There are ways to *predict the amount of corrosion* based upon the ingredients in the concrete times the length of time that they have been exposed to those elements. I'd like to know if anyone else found out anything more about this. This is interesting.
John Wright
The article I referenced is about 10 years old. I'm quite sure the magnetostrictive sensor technology has evolved significantly since then and that it will find corrosion in embedded rods as long as one end is accessible to fit the sensor to the rod. I am not sure how well the instrument can quantify the metal loss, but I think its fairly good.
I would be very wary of corrosion predictions in concrete, although I have no direct experience with them. It seems you would have to rely upon very good to excellent characterization of the concrete and the environment and hope for a very narrow range of predicted corrosion rates so that when you multiply rate x time you get a meaningful estimate of metal loss. Theoretical models may be OK if you want to do a very coarse sort on which concrete formulation or operating environment might be worse, but I would not want to rely on them as an absolute indication of remaining strength in the rebar.
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Hi Bill,
If it's anchor bolts (anchor rods-correct term) that he's checking, I would think you would have access to one end and therefore could use the info you are talking about. I'll have to look a little harder for some more info about this NDT method you have described, it sounds interesting.
John Wright
AFter your research on the various items listed, let us know what you found. I'm a little lazy today :)
GA