A hybrid sacrificial galvanic anode, an anodic system including the hybrid sacrificial anode, and a method of cathodically protecting steel reinforcement in concrete structures is provided. The hybrid anode provides initial steel polarization followed by long term galvanic protection without the use of batteries or external power supplies.

In a method for cathodically protecting and/or passivating a metal section in an ionically conductive material such as steel reinforcement in concrete or mortar, an impressed current or sacrificial anode communicates ionic current to the metal section and a storage component of electrical energy which can be a cell, battery or capacitor is provided as a component of the anode. The storage component can have replacement energy introduced by re-charging or replacing the component from an outside supply. Typically the cell or storage capacitor has an outer case which carries an anode material as an integral outer component. A mechanical clamp is provided to attach the assembly to a rebar. A current limiter is provided which prevents excess current draining the supply.

In a method for cathodically protecting and/or passivating a metal section in an ionically conductive material such as steel reinforcement in concrete or mortar, an impressed current or sacrificial anode communicates ionic current to the metal section and a storage component of electrical energy which can be a cell, battery or capacitor is provided as a component of the anode. The storage component can have replacement energy introduced by re-charging or replacing the component from an outside supply. Typically the cell or storage capacitor has an outer case which carries an anode material as an integral outer component. A mechanical clamp is provided to attach the assembly to a rebar. A current limiter is provided which prevents excess current draining the supply.

The present invention relates to a method for impregnating concrete with a non-aqueous electrolyte characterized in that an electric field is applied between electrodes mounted on the concrete surface and/or embedded in the concrete such that the non-aqueous electrolyte migrates into the concrete. Preferably, lithium ions are dissolved in the non-aqueous electrolyte.

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.

Provided is an aluminum alloy clad material including an aluminum alloy core material and a first brazing filler metal that is clad on one surface or both surfaces of the core material, wherein the core material and the first brazing filler metal each include an aluminum alloy having a predetermined composition, the existence density of AlMn based intermetallic compounds having a circle-equivalent diameter of at least 0.1 m in the first brazing filler metal before brazing heating is at least 1.010.sup.5 pieces/mm.sup.2, and the existence density of AlMn based intermetallic compounds having a circle-equivalent diameter of at least 2 m in the first brazing filler metal after brazing heating is at least 300 pieces/mm.sup.2. Further provided are a method for producing the aluminum alloy clad material and a heat exchanger employing the aluminum alloy clad material.

.[.A sacrificial anode assembly for cathodically protecting and/or passivating a metal section, comprising: (a) a cell, which has an anode and a cathode arranged so as to not be in electronic contact with each other but so as to be in ionic contact with each other such that current can flow between the anode and the cathode; (b) a connector attached to the anode of the cell for electrically connecting the anode to the metal section to be cathodically protected; and (c) a sacrificial anode electrically connected in series with the cathode of the cell; wherein the cell is otherwise isolated from the environment such that current can only flow into and out of the cell via the sacrificial anode and the connector. The invention also provides a method of cathodically protecting metal in which such a sacrificial anode assembly is cathodically attached to the metal via the connector of the assembly, and a reinforced concrete structure wherein some or all of the reinforcement is cathodically protected by such a method..]. .Iadd.A sacrificial anode assembly for cathodically protecting and/or passivating a metal section, includes a cell with an anode and a cathode, a connector attached to the anode of the cell for electrically connecting the anode to the metal section to be cathodically protected; and a sacrificial anode electrically connected in series with the cathode of the cell. The cell is otherwise isolated from the environment such that current can only flow into and out of the cell via the sacrificial anode and the connector. A method of cathodically protecting steel in concrete in which such the sacrificial anode assembly is connected to the steel in an initial step of passivation using a higher current and when the first step is terminated the sacrificial anode alone continues to provide protection. .Iaddend.

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 galvanic anode system for the corrosion protection of steel in concrete includes a galvanic anode material, which includes of zinc and alloys thereof, embedded in a solid electrolyte, and is characterized in that the galvanically available surface is larger, preferably at least twice as large, as the total geometrical surface of the metal anode. The galvanic anode system is also characterized in that, during operation, during which the anode disintegrates as a sacrificial anode, the galvanically active anode surface is reduced only slightly, preferably is not reduced up to at least 50%, in particular 75%, of the time during use.