An electrochemical process for the removal of chloride ions from reinforced concrete which comprises: passing a direct current between (i) an anode in electrical contact with an adherent coating containing a water retaining adhesive material and an aqueous electrolyte applied to an external surface of the concrete and (ii) a cathode which is located internally in the concrete, which processes causes chloride ions to migrate to the anode and wherein to reduce the production of chlorine gas, the coating contains, as a chlorine scavenger, solid calcium hydroxide or barium hydroxide or mixtures thereof the chlorine scavenger being present in an amount of at least 8 %, preferably 20 to 50 %, by weight based on the dry weight of the water retaining material.