[Antennas] RE:Concrete To Use For Your Tower

Sun, 8 Sep 2002 20:20:55 -0500

For non structural applications, fiberglass should do fine.  4 inch slabs,
small retaining walls, lightly loaded concrete tanks, etc.  Where there will
be thousands of pounds of tension, good old 5/8 and larger rebar will remain
king.  Concrete has very good compressive strength - hence the 3000 - 5000
psi rating.  In tension it breaks very easily.  High strength concrete is
never made from a pea gravel (sack-crete) mix, rather using 1 to 1 1/2 inch
rock in the mix to add tensile strength, when combined with rebar in the
areas of the concrete that will be put under tension, it is a very strong
structural member.  The rebar has ridges that prevent it pulling out and
does not depend on a good bond with the concrete mix, although if you have
ever taken a sledge and broken it off, it bonds better than you think.

Don't wait to put up your tower for a replacement to re-bar.

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Chris BONDE
Sent: Sunday, September 08, 2002 7:03 PM
To: Karl Kanalz
Cc: [email protected]
Subject: RE: [Antennas] RE:Concrete To Use For Your Tower

At 01:12 PM 2002-09-08 -0500, you wrote:
>Yes there are, Dave!  Again, the user must refer to the manufacturer's
>recommendations for the size of re-bar to be used and the recommended
>"pattern" of how the re-bar(s) are connected together (usually in a sort of
>"cage" shape).
>
>Karl K -  W8TIF
>McKinney, Texas
Has anyone studied the use of concrete with fibre glass ans
reinforcing?  There are a few reports out that the concrete is
stronger!  The rebar is usually oxidized before the concrete is pured hence
a poor bond sithe the concrete.  The fibre glass (I think that is the
strings that is mixed with the concrete) adheres and the mass is much
stronger as it becomes a solid mass rather than a mass interupted with poor
iron.

Has anyone anything thereon?

Chris opr Ve7HCB

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