Method of repairing steel reinforced concrete structure affected by chloride induced corrosion

Patent metadata

Field	Value
Publication number	US-9969656-B2
Application number	US-201414906609-A
Country	US
Kind code	B2
Filing date	Jul 21, 2014
Priority date	Jul 22, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A method of repairing a steel reinforced concrete structure ( 100 ) affected by chloride induced corrosion, comprising:
subjecting the reinforced concrete structure ( 100 ) to an electrochemical treatment so as to enrich material ( 102, 120, 140 ) embedding the steel reinforcement ( 110 ) with chlorides originating from corrosion pits ( 112 ) in the steel reinforcement; and replacing the material ( 102, 120, 140 ) embedding the steel reinforcement ( 110 ), which has been enriched with chlorides during the electrochemical treatment, with a repair material ( 124 ) that is relatively poor in chlorides.

First claim

The invention claimed is:

1. A method of repairing a steel reinforced concrete structure affected by chloride induced corrosion, comprising:
subjecting the reinforced concrete structure to an electrochemical treatment so as to enrich original material embedding a steel reinforcement with chlorides originating from corrosion pits in the steel reinforcement; and
replacing the original material embedding the steel reinforcement, which original material has been enriched with chlorides during the electrochemical treatment, with a repair material that is relatively poor in chlorides.

2. The method according to claim 1 , wherein the original material embedding the steel reinforcement is substantially concrete.

3. The method according to claim 2 , further comprising:
before subjecting the reinforced concrete structure to the electrochemical treatment, repairing a defect in the concrete embedding the steel reinforcement with temporary electric resistivity-matched repair mortar to ensure electrical homogeneity.

4. The method according to claim 3 , wherein replacing the concrete embedding the steel reinforcement after the electrochemical treatment comprises:
removing the concrete embedding the steel reinforcement that has been enriched with chlorides;
cleaning a surface of the steel reinforced concrete structure that was exposed due to the removal of the enriched embedding the steel reinforcement; and
applying and curing the repair material.

5. The method according to claim 2 , further comprising:
before subjecting the reinforced concrete structure to the electrochemical treatment, replacing concrete embedding the steel reinforcement with an electrolyte that will serve as the material embedding the steel reinforcement during the electrochemical treatment.

6. The method according to claim 5 , wherein replacing the electrolyte embedding the steel reinforcement after the electrochemical treatment comprises:
removing the electrolyte embedding the steel reinforcement that has been enriched with chlorides by the electrochemical treatment;
cleaning a surface of the steel reinforced concrete structure that was exposed due to the removal of the enriched electrolyte embedding the steel reinforcement; and
applying and curing the repair material.

7. The method according to claim 5 , wherein the electrochemical treatment comprises:
applying a distributed electrode to the electrolyte embedding the steel reinforcement, and
applying a DC voltage across the distributed electrode, as a positive terminal, and the steel reinforcement, as a negative terminal, thereby effecting a distributed current between the distributed electrode and the steel reinforcement.

8. The method according to claim 1 , wherein the repair material is concrete.

9. The method according to claim 2 , wherein the electrochemical treatment comprises:
applying a distributed electrode to the concrete embedding the steel reinforcement, and
applying a DC voltage across the distributed electrode, as a positive terminal, and the steel reinforcement, as a negative terminal, thereby effecting a distributed current between the distributed electrode and the steel reinforcement.

10. The method according to claim 9 , wherein the DC voltage is in the range of 5-40 V.

11. The method according to claim 9 , wherein a current intensity of the distributed current is in the range of 1-10 A/m 2 of steel reinforcement surface.

12. The method according to claim 9 , wherein the distributed current is flowing during a period in the range of 8-48 hours.

13. The method according to claim 9 , wherein a total charge that is exchanged between the terminals during the electrochemical treatment is in the range of 8-480 Ah/m 2 of steel reinforcement surface.

14. The method according to claim 13 , wherein a total charge that is exchanged between the terminals during the electrochemical treatment is in the range of 24-240 Ah/m 2 of steel reinforcement surface.

Assignees

• TNO
• Norwegian Univ Of Science And Technology

Inventors

• Polder Robert Benjamin
• Geiker Mette Rica

Classifications

• C04B41/5376 Primary

  Electrochemical desalination (electrochemical re-alkalisation C04B41/4566; drying by electro-osmosis E04B1/7007) · CPC title

• C04B41/72

  involving the removal of part of the materials of the treated articles, e.g. etching · CPC title

• C04B41/009

  characterised by the material treated · CPC title

• C04B32/02

  with reinforcements {(contains no documents; reinforcing elements E04C5/00)} · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title