The present invention relates to a method of installing an unbonded flexible pipe with a bore for transportation of fluid wherein the unbonded flexible pipe comprises an outer sheath, an inner sealing sheath inside the outer polymer sheath, an annulus between said outer sheath and said inner sealing sheath and at least one metallic armor layer comprising iron located in said annulus, wherein the method comprises filling at least a part of the annulus with a corrosion promoting liquid before or after installing the unbonded flexible pipe between a first installation and a second installation.

Corrosion protection of steel in concrete is provided by locating an anode assembly including both a sacrificial anode and an impressed current anode in contact with the concrete and providing an impressed current from a power supply to the anode. The impressed current anode forms a perforated sleeve surrounding a rod of the sacrificial anode material with an activated ionically-conductive filler material between. The system can be used without the power supply in sacrificial mode or when the power supply is connected, the impressed current anode can be powered to provide an impressed current system and/or to recharge the sacrificial anode from sacrificial anode corrosion products.

In a method of corrosion protection of rebar in concrete the sacrificial anode is held in place by wrapping a first wire around a first rebar portion and a second wire at second rebar portion and twisting together the first and second free ends to tension the wrappings. This can be used either on two separate rebars which are parallel or at right angles or can be used at longitudinally spaced positions on a single rebar where the rebar roughening prevents the two wrappings from sliding as the wires are tensioned by the twisting. In many cases a covering material such as a porous mortar is cast onto the outer surface of the anode and in this case the mortar and the wire are located such that the wire exits from the sacrificial anode at a position separate from the layer of covering material.

A method for producing cathodic protection for protecting reinforcing steel (2) in a reinforced concrete structure (1) is provided, in which reinforced concrete structures subjected to chloride-induced corrosion can be simply and durably protected against corrosion. Furthermore, the cathodic protection is also intended to be producible particularly quickly both for new buildings as well as when carrying out renovation/retrofitting work. For this purpose, a textile-reinforced concrete (8) is applied to the reinforced concrete, wherein the textile-reinforced concrete (8) comprises a carbon fabric (10) and a mortar, wherein a continuous electrical voltage is applied between a cathode and an anode and wherein the reinforcing steel (2) is used as the cathode and the carbon fabric (10) is used as the anode.

A corrosion protection cathode using an external power supply in which a reinforcing layer formed of a fiber base material is laminated with an adhesive layer on one surface of a conductive layer formed of a graphite sheet, and an electrolyte layer of an electrolyte-containing resin formed in a sheet shape and having adhesive power such that the layer is capable of being adhered to the conductive layer and to a surface layer of an object to be protected from corrosion is adhered by the adhesive power thereof to the other surface of the conductive layer, wherein the conductive layer always has a resistance value of 4 or less between any two points on the surface thereof on a side that comes into contact with the electrolyte layer.

A cathode protection method of embedded CFRP anode for reinforced concrete structure includes the following steps. Provide a preformed groove with a predetermined shape and size in a surface of a protection area of a reinforced concrete body, and remove dust in the preformed groove. Provide a CFRP member on the surface of the protection area of the reinforced concrete body. Coat an electrical conductive adhesive material between side surfaces of the reinforcing column of the CFRP member and the preformed groove and between the reinforcing plate and the reinforced concrete body. Connect the CFRP member with a positive electrode of an external DC power supply and the steel reinforcing element with a negative electrode of the external DC power supply.