Abstract: An array of anode assemblies for insertion at a plurality of locations in a gap between a section of a reinforced concrete structure and another solid structure is provided. Each anode assembly comprises an expandable member, an anode attached to the expandable member for protecting a steel reinforcement in the reinforced concrete structure, and an anode connector for interconnecting the array of anode assemblies. During use, each anode assembly of the array of anode assemblies is inserted into the gap, between the section of the reinforced concrete structure and the solid structure, at the plurality of locations. The expandable member of each anode assembly is configured to expand so as to press the anode into contact with a surface of the reinforced concrete structure.

Abstract: A reinforced concrete structure comprising a hardened concrete containing at least one steel reinforcement, a plurality of anode cavities and interconnecting slots formed within the hardened concrete, with the interconnecting slots interconnecting adjacent anode cavities with one another. A discrete galvanic anode is installed within each of the anode cavities. At least one connector for connecting the plurality of discrete galvanic anodes with the at least one steel reinforcement. A plurality of interconnecting galvanic anodes which each comprises a metallic element which has an interconnecting connector extending from opposed ends thereof. Each of the interconnecting galvanic anodes is installed within a respective interconnecting slot. First and second ends of the interconnecting connector are respectively connected to adjacent first and second discrete galvanic anodes.

Abstract: An array of anode assemblies for insertion at a plurality of locations in a gap between a section of a reinforced concrete structure and another solid structure is provided. Each anode assembly comprises an expandable member, an anode attached to the expandable member for protecting a steel reinforcement in the reinforced concrete structure, and an anode connector for interconnecting the array of anode assemblies. During use, each anode assembly of the array of anode assemblies is inserted into the gap, between the section of the reinforced concrete structure and the solid structure, at the plurality of locations. The expandable member of each anode assembly is configured to expand so as to press the anode into contact with a surface of the reinforced concrete structure.

Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete comprises a sacrificial metal that is capable to supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven from the sacrificial metal [1] to the steel [10] using a power source [5] converting oxygen and water [14] into hydroxyl ions [15] on the steel and drawing chloride ions [16] into the porous material [2] around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is them applied. This is preferably sacrificial cathodic prevention that is applied by disconnecting the power source and connecting the activated sacrificial node directly to the steel.

Abstract: A method of protecting steel in a reinforced concrete element is disclosed. The reinforced concrete of the element contains an electrolyte. The method involves providing a primary anode, which is a sacrificial anode, and providing a secondary anode, which is connected to a positive terminal of at least one source of direct current, ‘DC’, power. The primary anode and secondary anode are arranged to have an ionic connection with the steel in the reinforced concrete element via the electrolyte. The primary anode is connected to the steel in the reinforced concrete element using an electron conductor. The negative terminal of the source of DC power is connected to the steel in the reinforced concrete element using an electron conductor.

Abstract: An anode and backfill steel protector combination for inserting into at least one cavity which is mechanically formed in steel reinforced concrete. The anode and the backfill steel protector combination comprises an anode for insertion into the at least one cavity with the anode comprising a sacrificial metal element less noble than steel and a backfill which comprises a viscous and pliable ionically conductive material for insertion into the at least one cavity. The backfill is packaged within a cartridge and the cartridge is a cartridge for use with a cartridge which facilitates injecting the backfill from the cartridge into the at least cavity formed in the concrete. The backfill in a cartridge has a shelf life of at least 2 days.

Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete comprises a sacrificial metal that is capable fo supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven fromt eh sacrificial metal [1] to the steel [10] using a power source [5] converting oxygen and water [14] into hydroxyl ions [15] on the steel and drawing chloride ions [16] into the porous material [2] around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is them applied. This is preferably sacrificial cathodic prevention that is applied by disconnecting the power source and connecting the activated sacrificial node directly to the steel.

Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete. The anode system comprises a sacrificial metal that is capable of supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven from the sacrificial metal (1) to the steel (10) using a power source (5) for converting oxygen and water (14) into hydroxyl ions (15) on the steel and drawing chloride ions (16) into the porous material (2) around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is then applied. This is preferably a sacrificial cathodic prevention which is applied by disconnecting the power source and connecting the activated sacrificial node directly to the steel.

Abstract: The installation and use of embedded sacrificial anodes to protect reinforced concrete may be improved. In one example a cavity [2] is formed in the concrete [3] and a puttylike backfill [4] is placed in the cavity and a compact discrete anode comprising a sacrificial metal element [1] is inserted into the backfill and a space is provided into which the backfill may move when subjected to a pressure arising from the formation of voluminous sacrificial meal corrosion products and a high current is passed from the anode to the steel in the concrete to arrest steel corrosion and activate the anode in the backfill. The space may be provided by venting the backfill to space outside the cavity through an opening [5] or by including a void space within the backfill [6] or a void space within the cavity [7].

Abstract: The installation and use of embedded sacrificial anodes to protect reinforced concrete may be improved. In one example a cavity [2] is formed in the concrete [3] and a puttylike backfill [4] is placed in the cavity and a compact discrete anode comprising a sacrificial metal element [1] is inserted into the backfill and a space is provided into which the backfill may move when subjected to a pressure arising from the formation of voluminous sacrificial meal corrosion products and a high current is passed from the anode to the steel in the concrete to arrest steel corrosion and activate the anode in the backfill. The space may be provided by venting the backfill to space outside the cavity through an opening [5] or by including a void space within the backfill [6] or a void space within the cavity [7].

Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete. The anode system comprises a sacrificial metal that is capable of supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven from the sacrificial metal (1) to the steel (10) using a power source (5) for converting oxygen and water (14) into hydroxyl ions (15) on the steel and drawing chloride ions (16) into the porous material (2) around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is then applied. This is preferably a sacrificial cathodic prevention which is applied by disconnecting the power source and connecting the activated sacrificial node directly to the steel.

Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete comprises a sacrificial metal that is capable of supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven from the sacrificial metal [1] to the steel [10] using a power source [5] converting oxygen and water [14] into hydroxyl ions [15] on the steel and drawing chloride ions [16] into the porous material [2] around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is then applied. This is preferably sacrificial cathodic prevention that is applied by disconnecting the power source and connecting the activated sacrificial anode directly to the steel.

Abstract: A method of protecting steel in concrete is disclosed. It consists of connecting the steel (6) to a discrete sacrificial anode assembly (7) comprising a base metal (1), a relatively small quantity of catalytic activating agent in contact with the base metal and a substantially inert porous layer (3) that surrounds the base metal and catalytic activating agent. The inert porous layer efficiently maintains a sustainable concentration gradient of the catalytic activating agent between the base metal and the surrounding environment as a result of the electric field across this layer. The preferred porous layer comprises a material that exhibits a net repulsion of negative ions from its pore system and the preferred catalytic activating agent comprises doubly charged sulphate ions as small electric fields maintain very high concentration gradients of these ions resulting in high concentrations at the base metal surface and insignificant concentrations at the assembly periphery.

Abstract: This assembly provides a flexible method of attaching discrete sacrificial anodes to exposed steel in concrete construction to achieve an advantageous distribution of protection current. It comprises a base metal [1] that is less noble than steel, a conductor [6] connected to the base metal, a tying point [2] formed at least in part by the conductor, and a tie [4] that passes through the tying point [2] and around the steel [5]. The tie is used to physically tie the anode between steel bars prior to placing the concrete and in the process to electrically connect the anode to the steel. The tying point is open to facilitate adjusting the tie. The separation of the tie from an anode assembly with a tying point allows the tie to be selected during installation when the properties required by the application are known.

Abstract: A single anode system used in multiple electrochemical treatments to control steel corrosion in concrete comprises a sacrificial metal that is capable of supporting high impressed anode current densities with an impressed current anode connection detail and a porous embedding material containing an electrolyte. Initially current is driven from the sacrificial metal [1] to the steel [10] using a power source [5] converting oxygen and water [14] into hydroxyl ions [15] on the steel and drawing chloride ions [16] into the porous material [2] around the anode such that corroding sites are moved from the steel to the anode restoring steel passivity and activating the anode. Cathodic prevention is then applied. This is preferably sacrificial cathodic prevention that is applied by disconnecting the power source and connecting the activated sacrificial anode directly to the steel.

Abstract: The installation and use of embedded sacrificial anodes to protect reinforced concrete may be improved. In one example a cavity [2] is formed in the concrete [3] and a puttylike backfill [4] is placed in the cavity and a compact discrete anode comprising a sacrificial metal element [1] is inserted into the backfill and a space is provided into which the backfill may move when subjected to a pressure arising from the formation of voluminous sacrificial metal corrosion products and a high current is passed from the anode to the steel in the concrete to arrest steel corrosion and activate the anode in the backfill. The space may be provided by venting the backfill to space outside the cavity through an opening [5] or by including a void space within the backfill [6] or a void space within the cavity [7].

Abstract: A method of protecting steel in concrete is disclosed. It consists of connecting the steel (6) to a discrete sacrificial anode assembly (7) comprising a base metal (1), a relatively small quantity of catalytic activating agent in contact with the base metal and a substantially inert porous layer (3) that surrounds the base metal and catalytic activating agent. The inert porous layer efficiently maintains a sustainable concentration gradient of the catalytic activating agent between the base metal and the surrounding environment as a result of the electric field across this layer. The preferred porous layer comprises a material that exhibits a net repulsion of negative ions from its pore system and the preferred catalytic activating agent comprises doubly charged sulphate ions as small electric fields maintain very high concentration gradients of these ions resulting in high concentrations at the base metal surface and insignificant concentrations at the assembly periphery.

Abstract: This assembly provides a flexible method of attaching discrete sacrificial anodes to exposed steel in concrete construction to achieve an advantageous distribution of protection current. It comprises a base metal [1] that is less noble than steel, a conductor [6] connected to the base metal, a tying point [2] formed at least in part by the conductor, and a tie [4] that passes through the tying point [2] and around the steel [5]. The tie is used to physically tie the anode between steel bars prior to placing the concrete and in the process to electrically connect the anode to the steel. The tying point is open to facilitate adjusting the tie. The separation of the tie from an anode assembly with a tying point allows the tie to be selected during installation when the properties required by the application are known.

Abstract: 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.