Jim,
Universal Towers in their instructions for their free-standing aluminum
towers states that rebar is not needed for their concrete bases. Should I
put in rebar anyway?
73,
-john, W7AAY
----- Original Message -----
From: "Jim Lux" <jimlux@earthlink.net>
To: <K7LXC@aol.com>; <towertalk@contesting.com>
Sent: Friday, December 30, 2005 11:32 AM
Subject: [TowerTalk] rebar (was 900 MHz tower)
> At 06:43 AM 12/30/2005, K7LXC@aol.com wrote:
>
>> > However as far as welding goes, rebar CAN be welded, but it takes a
>>special
>>technique, and requires some knowledge of the bar material and the right
>>welding rod. This isn't a "get the old buzz box out and tack everything
>>together" kind of operation. And, as always with structural kinds of
>>things, you need to talk to your local regulators.
>>
>> It's been my experience that rebar in tower bases isn't usually
>>'structural'. It's primary purpose is to hold the concrete together while
>>it
>>cures to prevent cracks in it.
>
>
> Concrete has no real tension strength, so the rebar provides the needed
> tension strength. If your tower is a guyed tower with only compression
> loads on the big block o'concrete, you're right, the rebar might not be
> doing much. However, if you have a free standing tower which transmits
> bending loads to the concrete as tension (on the upwind side) and
> compression (on the downwind side), you'd better have the rebar in there.
> Even on a guyed tower, there are shear loads on the concrete, which, by
> definition, are a combination of tension and compression loads.
>
> Upshot.. rebar is most definitely structural.
>
>
>>Rebar schedules are in the drawings for each tower
>>so be sure to follow them.
>>
>> BTW rebar comes in # sizes; i.e. #4, #6, etc. This refers to 1/8
>> inch
>>increments. For example, #4 is 4/8ths or 1/2 inch; #6 is 6/8ths or 3/4
>>inch.
>>
>>Cheers,
>>Steve K7LXC
>>TOWER TECH
>
>
> Jim
>
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