A rebar cage sitting on gravel at the base of the hole is the same as
sitting on the dirt.
Moisture, seepage, that's what we want to protect the rebar from.
Gravel is suggested for tubular tower bases, where it is necessary to have a
drainage path for moisture/condensation that will build up inside the tower
tubes.
A concrete building footing may have gravel at the base, but the rebar is
still suspended inside the body of the concrete and is not to contact any
surface.
----- Original Message -----
From: "Sid Ashen-Brenner" <sashen@swbell.net>
To: <TowerTalk@contesting.com>
Sent: Sunday, August 10, 2003 3:53 PM
Subject: Re: [TowerTalk] Rebar cage for tower footing
> How about suspending the rebar cage from a couple of 2 x 4's above the top
> of the form with some rebar ties?
> Or the paving stones / bricks under the cage .. any of these should work!
> Shouldn't there be some Sand or Gravel at the bottom of the hole also??
>
> 73 de Sid n0obm
>
> At 16:21 08/10/2003 -0400, you wrote:
> >Bob,
> > Not a Civil Engineer by any stretch of the imagination but one of the
> >reasons for not having the rebar breach the concrete is rust. That
exposed
> >end will make a super-highway for rust and assuming there is a path,
> >eventually there will be no more rebar in your concrete. Instead there
will
> >be nice 1/2 inch paths with nothing but air - or worse - moisture in
them.
> > No idea where or when I read it but seem to recall the proper method
is to
> >put something like paving stones of the appropriate size under the rebar
> >such that, when the concrete is poured, the paving stones keep the rebar
> >away from the surrounding earth and themselves become sealed in the
> >concrete.
> >
> >Mike / W8DN
> >
> >----- Original Message -----
> >From: "Bob Gates" <regates@kingwoodcable.com>
> >To: "Tower Talk" <towertalk@contesting.com>
> >Sent: Sunday, August 10, 2003 4:11 PM
> >Subject: [TowerTalk] Rebar cage for tower footing
> >
> >
> > > I've noted the UST footing design for most/all their towers, and they
> >specify a
> > > rebar cage with the vertical pieces set approximately 3" above the
bottom
> >of the
> > > footing. This is obviously a clumsy undertaking in the real world,
> >because it
> > > would entail pouring 3" of concrete in the hole, let it set up, insert
the
> >cage
> > > and continue the pour. After 30 years in the construction business,
I've
> >seen a
> > > few footings poured, and many were designed by engineers who never had
to
> > > actually install their designs, such as spread footings which are
> >extremely
> > > labor intensive, and for no reason. To make a long question short,
any
> >civil
> > > engineers out there who see a problem with the rebar cage sitting on
the
> >dirt
> > > floor of the hole and pouring around it?
> > >
> > > Regards,
> > > Bob KG7KW
> > > _______________________________________________
> > >
> > > See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> >Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any
> >questions and ask for Sherman, W2FLA.
> > >
> > > _______________________________________________
> > > TowerTalk mailing list
> > > TowerTalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > >
> >
> >
> >_______________________________________________
> >
> >See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> >Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> >any questions and ask for Sherman, W2FLA.
> >
> >_______________________________________________
> >TowerTalk mailing list
> >TowerTalk@contesting.com
> >http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
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