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RE: Welding Rebar

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Ed,

Yes, you are technically allowed to weld rebar.  I would advise against it.
I have seen too many instances where the weld was not successful.  In order
to properly weld standard A615 rebar:
1.	You must have the mill test reports or assume the highest carbon in
the AWS procedure
2.	You must preheat and hold the temperature during welding.  (Small
bars do not hold temperature well)
3.	You must special inspect, and verify welder certification.

And after all that, you might have an adequate splice.

If you do allow it, smack it with a hammer enough to deform the bar at the
connection.  If it holds, it might be O.K.

Grade 40 rebar infers, but does not guarantee a lower carbon equivalent.
The lower the carbon, the more weldable.

I went to the mat on this one a few years ago.  When the testing was done,
the precast manufacturer changed its policy and required A706 rebar for all
its welded bar whether or not I was the engineer.  It scared them.

Regards,
Harold Sprague

> -----Original Message-----
> From:	Ed Fasula [SMTP:tibbits2(--nospam--at)metro.lakes.com]
> Sent:	Thursday, January 20, 2000 3:10 PM
> To:	seaint(--nospam--at)seaint.org
> Subject:	Welding Rebar
> 
> I understand that AWS allows welding A615 rebar with low hydrogen rods,
> and it seems to be an accepted procedure.  However, I have seen A706 rebar
> noted for use where weldability is important.  I can't see when
> weldability wouldn't be important when used in a welded application,
> unless it were a non-structural connection.  (In our area of rural
> construction, specifying A706 would probably be a first.)  
> 
> Chief Industries shows tie-rod welding details for A615 Gr. 40 with E70XX
> low hydrogen rods.  Does it matter that it's grade 40?  I don't find a
> reference telling if A615 is a carbon, high-carbon, or low-allow steel.  I
> would think Gr. 60 would be sort of a higher carbon mild steel, but I have
> no idea how it's made stronger than Gr. 40.  What if it's welded on a 20
> below zero day like we have in MN (well, rare this year), couldn't it get
> brittle?
> 
> Thanks for any information and/or advice.
> 
> Respectfully,
> 
> Ed Fasula EIT
>