Anode assembly for selective corrosion protection of metal parts in concrete

Abstract

Disclosed is an anode assembly for the corrosion protection of metal parts embedded in concrete. An ion-conducting material is placed between the metal part that is to be protected and the anode, which ion-conducting material exhibits higher ionic conductivity than the surrounding concrete, thus directing the protective current specifically towards the metal part. A galvanic sacrificial anode may be provided, made, e.g., from zinc and its alloys or aluminum and its alloys. The purpose of the material with higher ionic conductivity than the surrounding concrete is to selectively direct the protective galvanic current towards the metal part that is to be protected. The selective enhanced corrosion protection is especially beneficial for the protection of metal parts that are highly important for the structural integrity of concrete members, such as assembly of pre- or post-tensioning of concrete members, such as anchor-heads. The ion conducting material exhibits 20%, and more preferably 50%, higher conductivity than the surrounding concrete. A suitable ion-conducting material that exhibits ion-exchange properties may comprise tecto-alumo-silicate materials. The anode may be placed in close contact to or may be embedded into the ion-conducting material as well.

1 . A system for the corrosion protection of metal parts embedded in a concrete member, comprising:
 a metal part embedded in said concrete member;   a first anode; and   an ion-conducting material between said metal part and said anode, said ion-conducting material exhibiting higher ionic conductivity than concrete embedding said metal part, and wherein said ion-conducting material is configured to direct a corrosion-protective current towards said metal part.   
     
     
         2 . The system of  claim 1 , wherein the first anode is a galvanic sacrificial anode. 
     
     
         3 . The system of  claim 1 , wherein the first anode is composed of zinc, zinc alloys, aluminum, or aluminum alloys. 
     
     
         4 . The system of  claim 1 , wherein the first anode is composed of a mesh, grid, perforated sheet, perforated plate, ribbons, perforated ribbons, or strands. 
     
     
         5 . The system of  claim 1 , wherein the ion-conducting material exhibits at least 20% higher conductivity than said concrete embedding said metal part. 
     
     
         6 . The system of  claim 1 , wherein the ion-conducting material exhibits at least 50% higher conductivity than said concrete embedding said metal part. 
     
     
         7 . The system of  claim 1 , wherein the ion-conducting material is composed of a tecto-alumo-silicate material. 
     
     
         8 . The system of  claim 1 , wherein the first anode is embedded into the ion-conducting material. 
     
     
         9 . The system of  claim 1 , wherein the ion-conducting material contains a corrosion inhibitor. 
     
     
         10 . The system of  claim 1 , wherein the metal part comprises steel or cast iron. 
     
     
         11 . The system of  claim 1 , wherein the metal part forms part of an assembly for pre- or post-tensioning of concrete members. 
     
     
         12 . The system of  claim 1 , wherein said ion-conducting material fills an opening in said concrete formed by carving out a portion of said concrete embedding said metal part. 
     
     
         13 . The system of  claim 12 , further comprising a precast plug formed from said ion-conductive material and inserted into said opening and embedded into a bonding ion-conductive material. 
     
     
         14 . The system of  claim 13 , wherein a galvanic anode is embedded in said precast plug. 
     
     
         15 . The system of  claim 14 , wherein said galvanic anode embedded in said precast plug further comprises a galvanic sacrificial anode. 
     
     
         16 . The system of  claim 14 , wherein said galvanic anode embedded in said precast plug is composed of zinc, zinc alloys, aluminum, or aluminum alloys. 
     
     
         17 . The system of  claim 14 , wherein said galvanic anode embedded in said precast plug is composed of a mesh, grid, perforated sheet, perforated plate, ribbons, perforated ribbons, or strands. 
     
     
         18 . The system of  claim 14 , wherein said galvanic anode is wrapped or folded. 
     
     
         19 . The system of  claim 14 , wherein said first anode extends along an exterior surface of said concrete member to provide a combined galvanic protection of metal parts embedded in said concrete member. 
     
     
         20 . The system of  claim 1 , wherein said first anode is electrically connected with single or multiple electrical connections for each said metal part. 
     
     
         21 . The system of  claim 20 , wherein the electrical connections are made by welding, mechanically joining, or gluing. 
     
     
         22 . The system of  claim 21 , wherein the electrical connections comprise a conductive metal wire, strap, rod, or bar. 
     
     
         23 . The system of  claim 22 , wherein the electrical connections further comprise copper, zinc, aluminum, titanium, steel, or stainless steel. 
     
     
         24 . The system of  claim 20 , wherein the electrical connections are made to any metallic member of a pre- or post-tensioned assembly that includes said metal part.