Abstract: Mixed-metal-oxide (MMO) coated precious-metal tape is installed directly on concrete surfaces using an electrically non-conductive adhesive with semi-conductive coating or overlay, thereby obviating the need for slots or holes to the concrete structures which are not subject to direct moisture. The tape anodes may be installed on the concrete surfaces exposing metals without developing an electrical short circuit between the anode and the metals due to the non-conductive adhesive. The semi-conductive layer over the metal tape can distribute the CP current uniformly to the entire concrete surface without developing electrical short circuit. Overall the invention provides for quick and low cost installation on many concrete structures. Interconnections between the tape anodes and bare metal distribution elements may be made with conductive adhesive or spot welding.

Abstract: Improved deep well grounding systems of the kind used for cathodic protection of ground installations according to the invention employ a combination of materials for the casing of the central metallic anode and the backfill in the well which exhibit a degree of permeability sufficient to allow by-product gases develop in ordinary use of this system to escape, avoiding unwanted cavitation, while minimizing the migration of ground water and the attendant undesirable environmental pollution.