Decoding foreign rebar markings

[mikeiniraq]

Hoping someone can help here. I'm a U.S. military contracting officer in Iraq with absolutely no background or knowledge of the concrete business. The QA tech assigned to assist me came from the Air Force Space Command; he's just about as clueless as I am here. One of our projects specs ASTM A615 Grade 60 rebar. The rebar the Turkish contractor has brought in is marked KWT 16 560. This doesn't match any of the marking systems I've been able to find in my googling... can anyone interpret these markings and tell me if it's equivilant? Any net resources I can reference to document a decision to allow/disapprove use? Any help would be greatly appreciated; this is holding up a vital project to protect troops. Thanks, Mike

 

[Ussuri]

Can you ask the contractor to provide a technical note and certification for the reinforcement? Find out what standard the rebar has been manufactured too? I think your best bet is to go the company that supplied it.

In my experience marking on rebar usually indicates the country of manufacture and the specific mill, not the material properties of the bar itself. That said I have no idea what they do in Turkey.

You might also want try posting on the general concrete forum or the structural forum.

 

[mikeiniraq]

Tried getting cert from contractor; best he can come up with is invoice showing he ordered the right thing.

 

[SlideRuleEra]

mikeiniraq - Follow these links from the US Concrete Reinforcing Steel Institute:

http://www.crsi.org/rebar/id.html

and the UK Certification Authority for Reinforcing Steels

http://www.ukcares.co.uk/index.htm

Perhaps you can download helpful information (probably for a fee)

Best Wishes,
SlideRuleEra, USAFR (Ret)

http://www.SlideRuleEra.net

 

[Ingy]

mikeiniraq,

The 560 is probably 560 Mpa which is higher that 60 ksi. However, I spoke to someone who has done contracting work in Turkey and he agrees that mill certs are pretty universal. No mill cert, no approval. Contractors (and I am one) can get pretty motivated to produce documentation when their materials get rejected.

You may have some difficulty getting ASTM A615 specs in Turkey. I imagine that they use different standards, probably the European ones. You'll need to find out what European standard is the equivalent of A615. Sounds like someone should have specified products that are available in the area, not the US ones.

Good luck,

 

[Zambo]

mikeiniraq,

can you get the rebar tested. I know this may sound ridiculous but I've spent the last 20 years working overseas (I have to admit better postings than Iraq) and testing rebar has never been a problem. You need a tensile test and a bend test, chemical analysis of the steel would be useful but could perhaps be ignored as you don't have a mill cert to compare against anyway. Once you find the tensile strength you should be able to use the rebar even if you have to change the bar spacing to modify the construction to suit the design.

 

[4wilmar]

Sorry I missed your post, I don't often look under Concrete Formwork.

I spent a number of years working in the United Arab Emirates and a lot of Turkish rebar was used there, some good, some bad. I don't recall the KWT mark, but it has been a few years since I worked there. I suggest you contact Emirates Industrial Labs, Costain Labs or some of the other metalurgical labs in Dubia. They might be able to identify the manufacturer and let you know how reliable their rebar is. The 560 probably means MPA as Ingy mentioned but this seems a bit high. As I recall the typical strength was a 460 MPA European grade which corresponds to about 67 ksi. The 16 may be the bar diamenter in mm.

That said, I would also get some tested just to be sure. There may be some labs in Kuwait that can do it, if not, I am sure you can find a lab in Dubia that can do complete physical and chemical testing as per ASTM A615. You might also have them measure the bar deformations (some manufacturer's never change their rolling dies). You can also do a bend tests on site. Simply bend the bars 180 degree about the correct size mandrel as described in ASTM A615 and visually check for cracking on the outside radius.

The bars should also be delivered relatively free of rust and must be kept well covered to keep them that way. Don't forget that metric sizes are slightly different than typical american sizes (you may have to adjust your spacing).

Hope all this helps

 

[Ussuri]

460MPa used to correspond to high yield deformed rebar. However with the introduction of standardisation across europe 500MPa (types A, B, C) is now becoming more common.