On Jan 20, 2015, at 6:14 PM, Roger (K8RI) on TT <K8RI-on-TowerTalk@tm.net>
wrote:
On 1/20/2015 10:34 AM, Patrick Greenlee wrote:
It can be done that way and is often easier, but construction sites often have their own
way of doing things. The soil around here is often very moist (read, sloppy. The heavy
concrete casting "sometimes" can force its way through the muck that rapidly
fills the bottom portion of the hole. so for those conditions its easier, or even the
only way.. A form in the hole defeats the purpose of the concrete.
My front yard would be ideal for boring the hole and casting in place. It'd never work
in the back yard. In the NW corner, holes are temporary. They last long enough that the
casting could displace 2 or even three feet of mud "if you hurry" but would be
questionable as to what you'd get with a pour.
As an example: I dug the holes for the guy anchors for my 100' 45G. with the
intention of making and installing forms the next morning and doing the 3 pours
in the afternoon. The problem was that the next morning there were only two
holes and a 10' wide depression, about a foot deep where the hole had been for
the NW guy anchor. It would have worked if we had, had the form ready and
dropped it in the hole. We might have had to pump out the water but the hole
would have still been there. We didn't even need a form for the South hole.
My tower base http://www.rogerhalstead.com/ham_files/tower11.htm Undisturbed
soil was easily done!
and the hole that needed to be dug again
http://www.rogerhalstead.com/ham_files/tower12.htm It looks dry, but believe
me, it was only dry on top. It's almost like very wet Peat on the side toward
the camera.
We had no choice except to use a form, but Id make the forms differently if
doing it again. I'd set it up so as the pour filled the form the internal
braces could easily be pulled out. Getting those sides out was a real PITA. I
didn't worry about the braces. With the forms back-filled before the pour and
nature took car of at least half of that, the sides could have easily been
pulled up.after the concrete set.
OTOH if doing it again, I'd spend the money and go with a large crank-up had I
known I'd no longer be able to climb 7 years later..
The concrete in slop is still more effective than a single ground rod in slop.
73
Roger (K8RI)
On 1/20/2015 2:46 AM, Roger (K8RI) on TT wrote:
The ones I have seen are formed by using a large cardboard tube as a form to
cast the ground rod in concrete. (remove the form before planting the ground!)
An auger digs a hole of the proper diameter to the proper depth and the encased
rod is lowered into place. Not cheap, but very effective.
I don't get it. Why not augur the hole and place the rebar in it (with proper clearance
from dirt contact) and pour concrete into the hole? Why complicate the process, adding
the extra hassle and expense of the Sonatube. The hole in the ground is a
"wash", needed either way but no heavy equipment needed to pick up the formed
rebar filled concrete cylinder and you don't buy and destroy a big sonatube (cylindrical
cardboard form typically used to extend a pier hole above grade and similar.) Also it is
much easier to pour concrete into a hole in the ground than to fill a big sonatube.
Patrick NJ5G
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73
Roger (K8RI)
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