I'm doing some reasearch for an applications note I'm preparing on power and
grounding for audio and video systems, and wanted to mention the use of a Ufer
ground electrode. This got me into a google search on the resistivity of
concrete. It is
clear that resistivity varies over at least four orders of magnitude, depending
formulation, the mix of concrete and water, and how the concrete is poured.
I've come across an interesting webpage for what appears to be a small company
(garage?) selling specialty concrete.
There is now a lot of interest in the use of conductive concrete for snow
protection, and a variety of other uses. Here's a study of concrete for use as
ties in electric railroads.
It seems logical that varying the formulation of concrete could significantly
structural properties. But there would seem to be significant benefit from
structural steel within a poured concrete foundation into the ground system of
Several questions. Does anyone have experience with any of this? Pros and
I've seen suggestions that there are corrosion issues for steel within the
Would you want to use one of these specialty concretes to pour the base of your
Or would you use a more conventional concrete and mix it for lower resistivity?
The key issues with respect to grounding for lightning protection seem to be
of interconnecting wiring and the impedance to earth of the ground electrodes.
the electrode in conductive concrete will greatly increase the surface area in
with the earth, which should significantly reduce that portion of the impedance.
I would appreciate the collective wisdom of the assembled multitudes on these
While the thing that got me looking at this was this work-related project, the
is one of interest to all of us in our ham shacks.
Jim Brown K9YC
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