Hold on now.....
Do not weld the rebar... unless it is ASTM A706 grade or
you preheat the bars to 300 degrees F for #6 and smaller
and 500 degrees F for #7 and larger. This is from the
ANSI/AWS D1.4-98 Structural Welding Code - Reinforcing
Steel. This code in included in all Building Codes in
the US by citation.
Wire up the rebar cage and set in the hole. Use dobie
blocks at the bottom of hole to space the bars 3" clear
of the soil. Make sure the cage is 3" clear at the sides
also.
Dobie blocks are available at Building supply outlets
all over the US. Use 2x lumber and wire to hold the cage
in place from the top.
Try a search of towertalk using "reinforcing, rebar and
welding of rebar" as a keyword for many postings of mine
and others from the past concerning this subject.
Happy pouring and good luck
Hank Lonberg, S.E.,P.E. / KR7X
Lonberg Design Group
> In addition, welding all joints helps the rebar distribute lightning
> discharges through the concrete, making your base a "Ufer" ground, named
> after the investigator who established its value. The welded cage
> assembly can then be set into the hole and braced with 2X4, with wires
> or ropes to pull them out as the concrete is poured.
>
> 73 de Red
>
> FireBrick wrote:
>
> >As a retired mason contractor, I can see where you are going.
> >You want the verticals stable so you can easily wire the horizontals on
> >while in the hold.
> >Ideally, rebar should not extend through the concrete, rebar should not be
> >within 4" of the concrete.
> >This is to minimize moisture reaching the rebar and eventually rusting.
> >
> >If your worried about the rebar cage maintaining it's shape during
> >construction.
> >Stick the verticals in the ground at the surface. It's easier to work on
> >then in the hole.
> >Then have someone help you lift it and place in the hole.
> >
> >I also strongly suggest a little gravel in the bottom of the hole which
> >makes positioning the cage easier. You can wiggle it a bit to get it plumb.
> >
> >The trick with all rebar cages is to maintain their shape and position while
> >dumping and vibrating the concrete.
> >If you gut a couple boards and drill holes to match the vertical rears, you
> >can nail/clamp to braces on the surface.
> >
> >
> >----- Original Message -----
> >From: "Andrew Pfeiffer" <va3pl@cuic.ca>
> >To: <towertalk@contesting.com>
> >Sent: Thursday, September 19, 2002 11:36 AM
> >Subject: [Towertalk] Rebar Cage
> >
> >
> >>I become happy owner of TX455 crank up tower. I began planning the rebar
> >>cage.
> >>My questions is:
> >>Can vertical rebar members be driven let say 2 feet deep to the ground at
> >>the bottom of the hole or this is NO NO...
> >>
> >>Andy - VA3PL
> >>
> >>_______________________________________________
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> >>
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> >
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> >>
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> >
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> >>
> >>
> >
> >
> >_______________________________________________
> >Self Supporting Towers, Wireless Weather Stations, see web site:
> http://www.mscomputer.com
> >Call 888-333-9041 to place your order, mention you saw this ad and take an
> additional 5 percent off
> >any weather station price.
> >_______________________________________________
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>
>
>
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> _______________________________________________
> Self Supporting Towers, Wireless Weather Stations, see web site: >
> http://www.mscomputer.com
> Call 888-333-9041 to place your order, mention you saw this ad and take an
> additional 5 percent off
> any weather station price.
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