[Antennas] RE:Re-bar "Cage" To Use For Your Tower

Mon, 9 Sep 2002 17:18:30 -0500

>From my observation, Jacqui, and talking to varius concrete/re-bar experts 
in the area, it is not a good idea to "weld" re-bar when constructing a 
cage for a foundation or tower base (also a foundation).
Welding at the intersections of re-bar severely weakens the elements of 
the "cage" (both in the vertical and horizontal planes) and should not be 
used!
Instead, the pieces of re-bar (or "rebar" as more commonly used) should be 
tied together using galvanized wire, much like you would use a "twistie-ty" 
to seal a trash bag or the end opening of a bag of sliced bread.
Check your local highway construction designs (that is, if they use 
concrete) and you'll see that the re bar elements are "connected" by using 
steel wire "wraps", and not by welding.
I don't know the details of why all of this is so, but it just is, Jacqui! 
 I would tend to follow the real experts in this respect when it comes to 
rebar.
Karl K - W8TIF
McKinney, Texas
-----Original Message-----
From:	Jacqui [SMTP:[email protected]]
Sent:	Monday, September 09, 2002 4:39 PM
To:	Lyn Williams
Cc:	[email protected]
Subject:	Re: [Antennas] RE:Concrete To Use For Your Tower
I seem to remember a like article in QST not too long ago. It mentioned 
how
a hit would not blow up the base with this type of system. The rebarb was
welded together in a cage if this is the same thing. Jacqui N1DVE
Lyn Williams wrote:
> Theres another reason to use a re-bar cage in concrete.......
> lightning grounding! There is a type of ground system (specificially
> for lightning discharge...not good for rf) call an Uffer ground that was
> designed by the guys doing the grounding for nuclear facilities.
>> I've got a book around here somewhere at home on the topic.....I'll
> forward the title/author/publisher information this evening.
>> regards to the list
>> lyn
> wa4geh
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Your moderator for this list is:
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