On 9/22/2010 4:20 PM, Ron W8RJL wrote:
> Per Tashjian Towers, rebar that is to be welded should be type A706 and no
> smaller than #8 (1 " diameter). I talked to him when doing my cage for a
> LM-354. Also, Wicapedia says under Welding Rebar: 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. To
> weld rebar you must obtain a mill statement that the reinforcing is suitable
> for welding.Welding can reduce the fatigue life of the rebar, and as a
> result rebar cages are normally tied together with wire. Besides fatigue
> concerns welding rebar has become less common in developed countries due to
> the high labor costs of certified welders. Steel for prestressed concrete
> may absolutely not be welded. I hope this helps. 73, Ron W8RJL
If you look at the construction of most rebar cages it appears the cage
does little. It's the individual sections of rebar, their shape, and
overlap. IOW the cage is there to keep the concrete from losing
structural integrity.
I've welded quite a bit of rebar, but it was in uses where strength was
not paramount. "so far" I've never run into a problem with the welding,
but as has been stated the content of all but given specifications is
uncontrolled. It could be easy to come up with some alloys that would
end up with crystalline welds containing very little strength.
73
Roger (K8RI)
>
> ----- Original Message -----
> From: "Dan Bookwalter"<n8dcj@yahoo.com>
> To:<towertalk@contesting.com>
> Sent: Wednesday, September 22, 2010 3:32 PM
> Subject: [TowerTalk] Re-bar Cage - welding ??
>
>
>> 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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