My opinion:
Typically the rebar only adds strength to the concrete base. IOW, You
don't need as large a base, or as strong a mix when rebar is used. If
you were "positive" the base could maintain structural integrity under
any conditions you wouldn't need rebar.
Regardless of whether welded or tied, The rebar normally doesn't need a
rigid connections. The ties only keep the rebar in place during the pour.
If you don't need precision and are not making sharp bends in big stuff
you might be able to do the bending with a manual conduit bender.
Welding just makes building a rugged cage that can stand rough handling
easier. Just be sure to use rebar made for welding. Welds on the
normal stuff are quite fragile.
Bending rod, rerod, pipe, etc...into a circle is usually done with three
rollers. The rollers (Which usually have a radius cut into them to
keep the rod centered) are mounted in a triangular shape with the bottom
of the center one slightly below the tops of the outside rollers (The
height of this roller is adjustable). To bend much of anything, these
things can be pretty hefty. The distance between the rollers is
surprisingly short. Having them close reduces, or eliminates waste.
There is a bit of a learning curve, but it's neither steep nor long. A
rough explanation: The center roller is raised so the rod can be
inserted over the outside rollers and under the center roller. Then the
center roller is lowered and tension applied. The first pass produces a
shallow arc. The center roller is lowered for each successive pass which
tightens the arc eventually into a circle
I've seen the rollers mounted into the top of a steel bench with a
movable center wheel. The rollers are powered and a center screw, or
hydraulic ram powers the movement of the center roller. With those you
have to be aware of the thd of tht piece coming back, or you could
skewer yourself.
73
Roger (K8RI
On 10/20/2015 11:29 AM, StellarCAT wrote:
Rohn says to use 8 #7 rebar (SERIOUSLY! 7/8”!!) ... and then it shows ‘#4 circular ties 2 1/2” OC
with 2” cover with 24” laps’
huh?
I’ve always just dug a hole – usually around 3 x 3 x 3 ... put the tower section in (with temp guys) ... put in a
few pieces of 1/2” re bar and been done with it .... but now I have to follow the Rohn specifications which seem onerous
at best (I know, I know – guys that say “follow it to the letter”) ... and I’ve no clue what #4
circular tie is. SURELY its not #4 rebar BENT in a circle!?
Googling so far hasn’t shown me anything that helps.
Gary
K9RX
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
--
73
Roger (K8RI)
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|