Abstract: Cathodic protection system for the cathodic protection of a reinforced concrete structure, which system comprises a concrete structure containing steel reinforcement bars and an electrically conductive coating bonded to an external surface and in electrical contact with the structure, and wherein said electrically conductive coating is a non-cementitious coating comprising a matrix of an organic polymer containing electrical conductivity-providing particles of carbon coated with a conductive metal of a type possessing a natural passive oxide film which is itself electrically conductive, and an alkaline buffer material or combination of materials for inhibiting or preventing the build up of acidity in the coating when the cathodic protection system is in operation.

Abstract: Cathodic protection system for the cathodic protection of a reinforced concrete structure, which system comprises a concrete structure containing steel reinforcement bars and an electrically-conductive coating bonded to an external surface and in electrical contact with the structure, and wherein said electrically conductive coating is a non-cementitious coating comprising a matrix of an organic polymer containing electrical conductivity-providing particles of carbon coated with a conductive metal of a type possessing a natural passive oxide film which is itself electrically conductive, and an alkaline buffer material or combination of materials for inhibiting or preventing the build up of acidity in the coating when the cathodic protection system is in operation.

Abstract: An electrode comprising a first structure of a low conductivity non-metallic material spaced from a second structure of a high conductivity material which acts as a current distributor to the first structure, and a low melting metal or alloy of bismuth between and in contact with the structures.

Abstract: An electrolytic cell comprising at least one anode and at least one cathode and pipework for charging liquor to the electrolytic cell and pipework for discharging liquor from the electrolytic cell, in which at least one of the pipeworks is made in part of an electrically non-conducting material and which also comprises an electrically conducting electrode material positioned in the pipework, e.g. a section of pipework made of a metallic electrode material, and in which the electrode material is electrically connected directly or indirectly to the anode or cathode by means of an electrical connection external of the electrolytic cell.