My store bought rebar cage came welded up using weldable rebar. No tying
involved. The three vertical rebars are over an inch in diameter and
are skip welded to 3 inch wide 3/8 thick (I think) about 3 ft long
lengths of bar stock. The three pieces of bar stock have 3/4 inch holes
on 2 1/2 inch centers on the upper portion to mate with similar pieces
that are the three legs of the tower base. Tying the bar stock to the
rebar with wire would not be an option. Welding required. The cage was
hot dip galvanized after welding.
Patrick NJ5G
On 5/10/2017 1:23 AM, Roger (K8RI) on TT wrote:
They don't weld rebar, because, tying the cage together with wire is
faster and cheaper. It also allows cheaper material in the rebar. The
wiring came about with rebar covering large areas with may
crossovers. Those wires or welds just serve to hold the rebar in
place before and during the pour. The rebar's purpose is to keep the
concrete from cracking, or breaking under stress.
73, Roger (K8RI)
On 5/6/2017 Saturday 11:11 AM, Kevin Stover, AC0H wrote:
All
Welding rebar is not for your average Ham Radio doofi.
You need the right steel, the right sticks, the right wire/gas if MIG
welding, the correct technique (the hard part).
A welded connection when done right will be stronger that either the
base metal and weld medium used to make it. You are creating an alloy
when you weld. You don't need that for a tower base.
If welding rebar were the magic bullet they'd be doing it everywhere.
They aren't.
Below is the way it's supposed to be done.
On 5/5/2017 6:54 PM, Shawn Donley wrote:
Here's what I did. I found a local company that would supply, cut
and bend the rebar per the cage design specs. They had the
professional machinery to do this properly and accurately. That's
the hard part. Took it all home in my pickup truck and put it
together on-site using conventional rebar wires ties. I did order
several pieces of small diameter rebar and tied them on as diagonals
on each side to provide rigidity and have the cage hold it's shape.
Had the backhoe guy lower it into the hole after excavation, laying
it so that each vertical rebar was on thick concrete pavers to keep
the rebar from touching dirt (a bad thing which will cause the rebar
to rust, expand and fracture the concrete). Also want at least 3.5
inches between the cage and the dirt sidewalls for the same reason.
Good luck with your project.
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