From Wikipedia:
*******************
"The American Welding Society (AWS) D 1.4 sets out the practices for
welding rebar in the U.S. Without special consideration the only rebar
that is ready to weld is /W grade/ (Low-alloy --- A706). In the US,
most rebar is not suitable for welding. ASTM A 616 & ASTM A 617
reinforcing are re-rolled rail steel & re-rolled rail axle steel with
uncontrolled chemistry, phosphorus & carbon content."
*******************
Saying that rebar has "uncontrolled content" is somewhat of an
understatement, considering that (as far as I know) much of what you use
for normal construction could have come from old washing machines, bed
springs, wheelbarrows, 1971 Rambler frames, WWII destroyers, or even
older reclaimed rebar. Well, maybe not the Rambler frames ... even
rebar manufacturers have their dignity. Still, most rebar is spec'd for
a certain minimal tensile strength and as long as it meets that it gets
sold. I've worked with a LOT of rebar while building my house and the
difference from stick to stick bending and cutting it is significant.
Given the dependency of good welds on metallurgy and impurities it's no
wonder that welding rebar is discouraged except in critical situations
using rebar of known composition.
In my opinion, the best way to insure that a rebar cage has high
integrity is to use L-shaped bends that overlap at important junctions
(corners, etc). Ties merely hold the rebar in place prior to and during
the pour ... I'd use a bend/overlap if I really wanted to keep
everything bonded together afterward.
73,
Dave AB7E
On 9/22/2010 12:48 PM, Ryan Jairam wrote:
> I don't think that rebar is easy to weld. I haven't seen many places
> where it is welded. It's just formed into th cage, tied together and
> concrete is poured. I don't believe it makes a significant
> difference.
>
> Ryan, N2RJ
>
>
>
> On Wed, Sep 22, 2010 at 3:32 PM, Dan Bookwalter<n8dcj@yahoo.com> wrote:
>> I recall some discussion many years ago regarding welding re-bar , i do not
>> remember if the consensus was you shouldn't or you can ??
>>
>> Also , since I got my TX-472 about 8 years ago they have changed the re-bar
>> cage
>> configuration , anyone know why ? i assume they must have discovered the old
>> one
>> was inadequate or some jurisdictions didn't like it ?
>>
>> Dan N8DCJ
>>
>>
>>
>> _______________________________________________
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>
>
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