Method for the galvanic protection of a reinforced concrete structure

Abstract

The invention relates to the galvanic protection of a concrete structure ( 10 ) comprising metal reinforcements ( 12 ). Holes ( 15 ) are previously made in the structure, for receiving sacrificial anodes. Before arranging said sacrificial anodes, decontamination electrodes ( 16 ) and an electrolyte are inserted into the holes in order to carry out a decontamination phase wherein the negative terminal of a power supply ( 18 ) is electrically connected to the reinforcements of the structure and the positive terminal of the power supply is electrically connected to the decontamination electrodes. Once the power supply has been activated for a certain amount of time in order to attract the chloride ions to the decontamination electrodes and the electrolyte, the electrolyte and the decontamination electrodes are removed from the holes ( 15 ) and the sacrificial anodes are sealed therein and then electrically connected to the reinforcements.

1 . A method for galvanic protection of a concrete structure having metallic armatures, the method comprising:
 boring holes in the structure;   inserting a decontamination electrode and an electrolyte into at least one of the holes;   electrically connecting a negative terminal of a current source to the armatures and a positive terminal of the current source to each decontamination electrode;   activating the current source;   removing the electrolyte and each decontamination electrode;   arranging and sealing sacrificial anodes in the holes bored in the structure; and   electrically connecting the sacrificial anodes to the armatures.   
     
     
         2 . The method of  claim 1 , wherein the decontamination electrode is made of a stainless material, in particular titanium, of stainless steel or of carbon. 
     
     
         3 . The method according to  claim 1  wherein the decontamination electrode is formed as a tube or spirally wound wire. 
     
     
         4 . The method according to  claim 1  wherein the decontamination electrode is electrically connected to the positive terminal of the current source by a wire made of stainless material, in particular titanium, on at least part of its length on the side of the decontamination electrode. 
     
     
         5 . The method according to  claim 1  wherein the electrolyte is removed from each hole by applying a stream of water or air. 
     
     
         6 . The method according to  claim 1  wherein the electrolyte is in the form of a gel. 
     
     
         7 . The method according to  claim 6 , wherein the electrolyte is a mixture comprising water, a gelifying agent or water retainer, such as methylcellulose, and a base. 
     
     
         8 . The method according to  claim 7 , wherein the base is sodium hydroxide. 
     
     
         9 . The method according to  claim 7 , wherein the base is potassium carbonate to re alkalinize the concrete around the armatures. 
     
     
         10 . The method according to  claim 1  wherein the current source comprises a battery or DC power supply connected to the mains, activated to supply current in a range of 0.5 to 1 A per square meter of armatures. 
     
     
         11 . The method according to  claim 1  wherein the sacrificial anodes are zinc-based. 
     
     
         12 . The method according to  claim 1  wherein the decontamination electrode is a tool used several times. 
     
     
         13 . The method according to  claim 1  wherein the holes have a depth greater than a depth required for inserting the sacrificial anodes.