Building codes now REQUIRE Ufer grounds in many jurisdictions for new
foundations. Codes also REQUIRE that rebar be covered with concrete,
usually a minimum of 3" to prevent corrosion ingress along the rods. So
it is reasonable to extrapolate that ground wires connected to the rebar
should not exit the concrete below grade and certainly ground rods into
soils shouldn't be embedded in structural concrete below grade. Per
codes, buried connections need to be brazed or Cadweld. Foundation
Ufer's are connected to by bending the end of a 20' rebar to above top
of the footing so the connecting ground wire isn't buried and the
connection can be inspected.
I've read about some ground rods installed into concrete cylinders to
increase the soil contact surface area, but don't know how widely this
is used.
Grant KZ1W
On 7/17/2013 9:18 AM, Skip K3CC wrote:
I'm not sure I understand the thread however, NEVER EVER, ground
anything
into the concrete base !!!!!!! NEVER use any ground rods in
concrete !!!!
If you would get a lightening strike, the current would carry into the
concrete
and boil off the water. When this happens the concrete will explode !!!
If you must ground a tower base I use 4 rods spaced about 4 ft from
the base, Cad weld
the wire onto the rod and make a physical connection to the tower on
all legs. Bond
the wire with at least 2 clamps onto the tower base using a conductive
paste . Years ago I would pour Copper Sulfate
around the tower to aid in the ground conductivity. As a point check
the tightness of the
clamps every few months
it's not the best but who can afford the grounding system that works
de Skip K3CC _______________________________________________
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