I would suggest anyone interested in this subject should Google "Ufer
ground" and get the real facts on the subject. The key to the "concrete
encased ground electrode" is a properly installed rebar reinforcing in
the concrete base.
Burt VE2BMQ
Ed Bathgate wrote:
>
>
>
> I'm going to disagree with the following posting:
>
> If the tower is bolted to galvanized pipe that is embedded in concrete of
> which a significant amount is in contact with soil, you have a
> "concrete-encased grounding electrode" which is hard to improve upon. It is
> not likely that a ground rod would be worthwhile, since damp concrete
> (concrete in intimate contact with soil at grade level) is a fairly good
> conductor, and such a footing or foundation has hundreds of times the
> surface area of a ground rod.
>
> I have read Ericsson specs for cellular tower installation in that
> disagrees with the previous statement.
>
> Standard concrete without conductive enhancing materials can crack, pop
> or crumble if subjected to a direct lightning strike if ground rods are
> not properly installed. The water contained within the concrete will
> vaporize instantly causing the concrete to fail.
>
> There are types of conductive concrete mixes or additives that can be
> used, but the most common practice is to use a ground rod from each leg
> with a copper wire bonded to each tower leg.
>
> Our mfg building at work is made from steel I-Beams into concrete. I
> have noticed each I-Beam has its own ground connection. The strap is
> bolted to the beam about 1" above the concrete, then disappears into the
> concrete, and suspect there is a ground rod going into the soil beneath
> the concrete piling, but that’s just a theory, as I dident see it before
> the mud was poured.
>
> Ed N3SDO
>
>
>
>
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