Thanks Glenn, Harold & Scott.
The bar does not meet the weight limit of A615 due to a lesser diameter. Specific weight/density, yield strength, elongation etc are within limits.
Now if we rephrase, if these bars are used by decreasing the spacing appropriately and providing an equal As/ft2 and a greater perimeter of bars/ft2; any comments from an engineering point of view (keeping codes aside). Wouldn't the performance improve as we are providing a greater perimter area and matching the steel area.
Best regards,
Shiraz Shahid.
From: Scott Maxwell [mailto:smaxwell@umich.edu]
Sent: August 12, 2009 23:37
To: seaint@seaint.org
Subject: Re: Deformed bars - Permissible variation in weight
I generally agree with Harold.
Where I might differ a little from a philosophical point of view would be that I might find out WHY the weight is not meeting the ASTM spec. If it is just because the bar's diameter is less than what it should be or was specified (i.e. Just less bar material per bar) but that it is otherwise ASTM qualifying material, then it might be OK to accept and just make sure that you decrease spacing or up the specified bar diameter (i.e. Change from say a #5 to a #6), but that would be purely a choice of the engineer.
If the weight is off because the material is not of the proper density, however, then I would definitely reject it.
But that is purely looking at it from pure engineering/technical basis. If you factor in what the code may or may not permit, then strictly speaking ACI 318 requires reinforcement to be ASTM A615, A706 or ASTM A996. Technically, if the bar then does not meet ASTM specs, ACI 318 does not technically permit it. How strictly that may or may not be enforced is really a question for the local code official. But, even if the local code official will allow it, your rear end could be left hanging out in the breeze for "violating" the "standard of care".
So, from a non-technical point of view (i.e. Potential liability or code point of view), I would likely reject it.
Regards,
Scott
Adrian, MI
On 8/12/09 12:44 PM, "Harold Sprague" <spraguehope@hotmail.com> wrote:All of the testing done for rebar in bond, anchorage, lap, etc. was predicated on testing of bars meeting the ASTM (I presume A 615 or 706). Without compliance with the ASTM, that empirically derived information is void.
If your particular application is fairly forgiving or conservative and you have assurance of the other parameters of the ASTM are in compliance, it is your judgment call as an engineer to accept the rebar or not.
I would not accept the rebar. I have been asked too many times to accept lesser quality. When I was an iron worker, I would not even ask. I would provide my work in compliance with the specifications. If I screwed up, I would fix it. Rebar suppliers are no different.
Regards, Harold Sprague
From: sshahid@engineering-solutions.biz
To: seaint@seaint.org
Subject: Deformed bars - Permissible variation in weight
Date: Wed, 12 Aug 2009 16:28:13 +0500
We have a situation where the test results give under weight bars (approx 15%), exceeding the 6% permissible variation in weight by ASTM. If we account for the reductions in weight/diameter by decreasing spacings and providing ample steel area, is there any codal provision restricting it.
Best regards,
Shiraz Shahid.
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Thursday, August 13, 2009
Re: Deformed bars - Permissible variation in weight
It is engineering judgement to use the rebar or not; but please consider that there is a problem with these bars not meeting A615. Perhaps the weight loss is not in the diameter but actually in the deformation ribs? If this is the case, bond of the concrete to the bar is impacted.
I would reject the bars for not meeting specs. If you want, ask the supplier for certification to a small bar size. I would not take on the liability of the bar manufacturer.
Paul.
Phoenix
On 8/12/09, Shiraz Shahid <sshahid@engineering-solutions.biz> wrote: