WO2018169495A1 - Sacrificial anode for steel reinforcement in concrete - Google Patents
Sacrificial anode for steel reinforcement in concrete Download PDFInfo
- Publication number
- WO2018169495A1 WO2018169495A1 PCT/TH2017/000021 TH2017000021W WO2018169495A1 WO 2018169495 A1 WO2018169495 A1 WO 2018169495A1 TH 2017000021 W TH2017000021 W TH 2017000021W WO 2018169495 A1 WO2018169495 A1 WO 2018169495A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- zinc
- assembly
- concrete
- anodes
- cementitious material
- Prior art date
Links
- 239000004567 concrete Substances 0.000 title claims abstract description 19
- 229910000831 Steel Inorganic materials 0.000 title claims description 8
- 239000010959 steel Substances 0.000 title claims description 8
- 230000002787 reinforcement Effects 0.000 title description 2
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims abstract description 40
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 18
- 239000011701 zinc Substances 0.000 claims abstract description 18
- 238000004210 cathodic protection Methods 0.000 claims abstract description 12
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims abstract description 10
- 239000004576 sand Substances 0.000 claims abstract description 9
- 229910001297 Zn alloy Inorganic materials 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims abstract 8
- 230000003213 activating effect Effects 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims 4
- 229910052751 metal Inorganic materials 0.000 claims 4
- 239000002184 metal Substances 0.000 claims 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims 2
- 229910001335 Galvanized steel Inorganic materials 0.000 claims 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 claims 1
- 239000008397 galvanized steel Substances 0.000 claims 1
- 239000010935 stainless steel Substances 0.000 claims 1
- 229910001220 stainless steel Inorganic materials 0.000 claims 1
- 238000002161 passivation Methods 0.000 abstract description 6
- 239000000203 mixture Substances 0.000 abstract description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 24
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 10
- 239000004570 mortar (masonry) Substances 0.000 description 10
- 230000007797 corrosion Effects 0.000 description 7
- 238000005260 corrosion Methods 0.000 description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 description 4
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical group [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000011150 reinforced concrete Substances 0.000 description 3
- 230000003014 reinforcing effect Effects 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000012190 activator Substances 0.000 description 2
- 239000000017 hydrogel Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 239000011440 grout Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- -1 seawater Chemical compound 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010455 vermiculite Substances 0.000 description 1
- 229910052902 vermiculite Inorganic materials 0.000 description 1
- 235000019354 vermiculite Nutrition 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
- E04B1/62—Insulation or other protection; Elements or use of specified material therefor
- E04B1/64—Insulation or other protection; Elements or use of specified material therefor for making damp-proof; Protection against corrosion
- E04B1/642—Protecting metallic construction elements against corrosion
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F2201/00—Type of materials to be protected by cathodic protection
- C23F2201/02—Concrete, e.g. reinforced
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F2213/00—Aspects of inhibiting corrosion of metals by anodic or cathodic protection
- C23F2213/20—Constructional parts or assemblies of the anodic or cathodic protection apparatus
- C23F2213/22—Constructional parts or assemblies of the anodic or cathodic protection apparatus characterized by the ionic conductor, e.g. humectant, hydratant or backfill
Definitions
- This invention is related to sacrificial anode cathodic protection of reinforcing steel in concrete.
- the alkaline environment of concrete will change the condition of reinforcing steel from corrosion state to passive state.
- This passive state will help to prevent the reinforcing steel from corrosion.
- concrete is porous. If concrete is surrounded by water or moisture containing chloride such as seawater, brackish water, deicing salt, salty ground water and etc. for many years, the concrete will be contaminated with chloride ions. Finally, chloride ions will attack the reinforcing steel and cause corrosion.
- Carbonation is another serious problem for reinforced concrete. Carbonation reduces pH in concrete from between 12.6 and 13.8 to about 8 which will cause the condition of the reinforcing steel to shift from passive state back to corrosion state.
- the first is to minimize or delay penetration of chloride ions or carbon dioxide using coating techniques or some additive to make concrete more difficult for penetration.
- the second is to allow chloride ions or carbon dioxide into the reinforced concrete but prevent the reinforcing steel from corrosion using cathodic protection technique.
- the first method cannot control the corrosion completely because the coating is damaged or the concrete is cracked always. Prevention of the coating or concrete from damage or crack is nearly impossible. Therefore, prevention of chloride ions or carbon dioxide to penetrate concrete is nearly impossible as well or will cost a lot of money.
- ICCP impressed current cathodic protection
- SACP sacrificial anode cathodic protection
- ICCP needs external power supply, inert anodes and wiring to complete the circuit of cathodic protection system.
- the ICCP will require additional maintenance and monitoring which will result in additional operating costs.
- SACP uses sacrificial anodes such as zinc, aluminium, magnesium and their alloys which have lower electrochemical potentials than steels or cathodes. Therefore, current flow in the cathodic protection system comes from the potential difference between the anodes and cathodes.
- the major advantages of SACP are easier installation, less initial cost, maintenance and monitoring, higher reliability and less risk to hydrogen embrittlement in high strength prestressed steel because of low driving voltage.
- the ionically conductive hydrogel is attached to at least a portion of the anode.
- the anode is in elongated foil form.
- the anode and the hydrogel are flexible and are conformed to the eroded area.
- LiOH lithium hydroxide
- the electrochemical activating agent is lithium nitrate (L1NO 3 ), lithium bromide (LiBr) or mixture of L1NO 3 and LiBr to enhance the performance of embedded anodes.
- the electrochemical activating agent is lithium nitrate (L1NO 3 ), lithium bromide (LiBr) or combination.
- the performance of sacrificial anode is enhanced by the use of mixture of chemicals and inert water absorbent solids, bentonite, vermiculite or combination, in a cementitious grout.
- the present invention relates to sacrificial anode cathodic protection of reinforcing steel in concrete.
- the sacrificial anodes for reinforced concrete in many patents are zinc, aluminium and alloys thereof.
- zinc and its alloys are preferred as sacrificial anode.
- Aluminium and its alloys tend to cause cracking in concrete because of higher volume expansion after they provide the current to the reinforcing steel for some period of time.
- the zinc or zinc alloys must be surrounded in the environment with high pH to prevent passivation. The pH should be at least 14.
- LiOH, NaOH or potassium hydroxide (KOH) can be used to activate zinc or zinc alloys. However, NaOH and KOH will react with silica aggregates to form gel.
- This reaction is called alkali silica reaction or ASR.
- Lithium ion can provide protection against ASR in concrete so LiOH is preferred as activator.
- NaOH or KOH can also be used as activator for zinc and zinc alloys but they need to mix with LiOH to prevent ASR.
- the amount of LiOH, NaOH and KOH in mortar is greater than 2%, 4% and 5% by weight respectively.
- concentration of LiOH, NaOH and KOH in mortar will become lower after the anode has been used for many years because of the reaction and dilution. This will result in the passivation of anodes.
- higher concentration of the chemicals minimum 4% LiOH, 8% NaOH or 10% KOH
- the control of sand size or combination is used. The best combination is minimum 4% LiOH by weight and sand size about 30 to 60 of
- Figure 1 illustrates the average results of the current output of the zinc anodes encased in different mortar.
- the solid line represents average current output of zinc anodes covered by the mortar with sand size number about 30 to 60 of US standard sieve and minimum 4% LiOH by weight. While the dash line represents current output of zinc anodes covered by the mortar with sand size number higher than 60 of US standard sieve and minimum 4% LiOH by weight.
- the letter F, S and D stand for fresh water, salt water with 3% NaCl and dry condition in the dam as described in ASTM G109 - 99.
- the zinc anodes covered by the mortar with sand size number about 30 to 60 of US standard sieve and minimum 4% LiOH by weight can provide better uniform current output.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Architecture (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Prevention Of Electric Corrosion (AREA)
Abstract
The sacrificial anode cathodic protection for reinforcing steel in concrete is accomplished and enhanced by mixture control of cementitious material covering zinc or zinc alloy anode. At least 4% lithium hydroxide by weight of the cementitious material is required to prevent the passivation of the zinc anodes after use for many years. The zinc anodes covered by the cementitious material with sand size number about 30 to 60 of US standard sieve provide better uniform current output. Combination of minimum lithium hydroxide and sand size control in the cementitious material will improve the anodes performance and prevent them from passivation.
Description
SACRIFICIAL ANODE FOR STEEL REINFORCEMENT IN CONCRETE
Technical Field
This invention is related to sacrificial anode cathodic protection of reinforcing steel in concrete.
Background Art
Normally, the alkaline environment of concrete will change the condition of reinforcing steel from corrosion state to passive state. This passive state will help to prevent the reinforcing steel from corrosion. However, concrete is porous. If concrete is surrounded by water or moisture containing chloride such as seawater, brackish water, deicing salt, salty ground water and etc. for many years, the concrete will be contaminated with chloride ions. Finally, chloride ions will attack the reinforcing steel and cause corrosion.
Carbonation is another serious problem for reinforced concrete. Carbonation reduces pH in concrete from between 12.6 and 13.8 to about 8 which will cause the condition of the reinforcing steel to shift from passive state back to corrosion state.
To prevent these corrosion problems, there are two favorite methods. The first is to minimize or delay penetration of chloride ions or carbon dioxide using coating techniques or some additive to make concrete more difficult for penetration. The second is to allow chloride ions or carbon dioxide into the reinforced concrete but prevent the reinforcing steel from corrosion using cathodic protection technique.
The first method cannot control the corrosion completely because the coating is damaged or the concrete is cracked always. Prevention of the coating or concrete from damage or crack is nearly impossible. Therefore, prevention of chloride ions or carbon dioxide to penetrate concrete is nearly impossible as well or will cost a lot of money.
For cathodic protection system (CP), there are two types, impressed current cathodic protection (ICCP) and sacrificial anode cathodic protection (SACP). ICCP needs external power supply, inert anodes and wiring to complete the circuit of cathodic protection system. Thus, the ICCP will require additional maintenance and monitoring which will result in additional operating costs.
SACP uses sacrificial anodes such as zinc, aluminium, magnesium and their alloys which have lower electrochemical potentials than steels or cathodes. Therefore, current flow in the cathodic protection system comes from the potential difference between the anodes and cathodes. The major advantages of SACP are easier installation, less initial cost, maintenance and monitoring, higher reliability and less risk to hydrogen embrittlement in high strength prestressed steel because of low driving voltage.
In US Patent 5,292,411 by Bartholomew et al., the ionically conductive hydrogel is attached to at least a portion of the anode. The anode is in elongated foil form. The anode and the hydrogel are flexible and are conformed to the eroded area.
In US Patent 6,022,496 by Page, zinc or zinc alloy anode is surrounded by mortar containing lithium hydroxide (LiOH). LiOH is added to maintain high pH in the mortar and prevent the anode from passivation.
In US Patent 6,193,857 by Davison and Gorrill, at least 2% of LiOH or 4% of sodium hydroxide (NaOH) is added to mortar surrounding the anode to prevent passivation.
In US patent 7,488,410 by Bennett et al., the electrochemical activating agent is lithium nitrate (L1NO3), lithium bromide (LiBr) or mixture of L1NO3 and LiBr to enhance the performance of embedded anodes.
Finally, in the PCT, WO 2007/126715 by Bennett, the electrochemical activating agent is lithium nitrate (L1NO3), lithium bromide (LiBr) or combination. Moreover, the performance of sacrificial anode is enhanced by the use of mixture of chemicals and inert water absorbent solids, bentonite, vermiculite or combination, in a cementitious grout.
Disclosure of Invention
The present invention relates to sacrificial anode cathodic protection of reinforcing steel in concrete. The sacrificial anodes for reinforced concrete in many patents are zinc, aluminium and alloys thereof. In this invention, zinc and its alloys are preferred as sacrificial anode. Aluminium and its alloys tend to cause cracking in concrete because of higher volume expansion after they provide the current to the reinforcing steel for some period of time.
The zinc or zinc alloys must be surrounded in the environment with high pH to prevent passivation. The pH should be at least 14. LiOH, NaOH or potassium hydroxide (KOH) can be used to activate zinc or zinc alloys. However, NaOH and KOH will react with silica aggregates to form gel. This reaction is called alkali silica reaction or ASR. Lithium ion can provide protection against ASR in concrete so LiOH is preferred as activator. NaOH or KOH can also be used as activator for zinc and zinc alloys but they need to mix with LiOH to prevent ASR.
Conventionally, the amount of LiOH, NaOH and KOH in mortar is greater than 2%, 4% and 5% by weight respectively. However, the concentration of LiOH, NaOH and KOH in mortar will become lower after the anode has been used for many years because of the reaction and dilution. This will result in the passivation of anodes. To prevent this problem and enhance the anode performance in concrete, higher concentration of the chemicals (minimum 4% LiOH, 8% NaOH or 10% KOH), the control of sand size or combination is used. The best combination is minimum 4% LiOH by weight and sand size about 30 to 60 of
US standard sieve. The zinc anodes with cover are installed in the test specimens conformed to ASTM G109 - 99. ASTM C0876 - 91 is used to determine the potentials of the reinforcing steels and 100 mV polarization decay method is used to prove the cathodic protection of the reinforcing steels in concrete. The current flows from the zinc anodes to the steel cathodes are also measured. Both mortar with sand size number about 30 to 60 and higher than 60 of US standard sieve and minimum 4% LiOH by weight help to improve the performance of zinc anodes and result in minimum 161 mV polarization decay of the reinforcing steels which prove the cathodic protection.
Description of the Drawing
Figure 1 illustrates the average results of the current output of the zinc anodes encased in different mortar. The solid line represents average current output of zinc anodes covered by the mortar with sand size number about 30 to 60 of US standard sieve and minimum 4% LiOH by weight. While the dash line represents current output of zinc anodes covered by the mortar with sand size number higher than 60 of US standard sieve and minimum 4% LiOH by weight. The letter F, S and D stand for fresh water, salt water with 3% NaCl and dry
condition in the dam as described in ASTM G109 - 99. The zinc anodes covered by the mortar with sand size number about 30 to 60 of US standard sieve and minimum 4% LiOH by weight can provide better uniform current output.
Claims
1. An assembly for cathodic protection of reinforcing steel in concrete structure, comprising:
at least one metal anode having more negative electrode potential than steels;
at least one elongated metallic conductor bonded to the metal anode(s);
an ionically conductive material which contains electrochemical activating agent for covering the metal anode(s).
2. The assembly as claimed in claim 1 wherein the metal anode is zinc or zinc alloy.
3. The assembly as claimed in claim 1 wherein the elongated metallic conductor is mild steel, galvanized steel or stainless steel.
4. The assembly as claimed in claim 1 wherein the ionically conductive material is a cementitious-based material.
5. The assembly as claimed in claim 4 wherein the cementitious-based material is made from sand size number about 30 to 60 of US standard sieve.
6. The assembly as claimed in claim 1 wherein the electrochemical activating agent is alkaline hydroxide present in sufficient amount to raise the pH of the covering material above about pH 14.
7. The assembly as claimed in claim 6 wherein the alkaline hydroxide is at least 4% lithium hydroxide by weight of the cementitious-based material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/TH2017/000021 WO2018169495A1 (en) | 2017-03-16 | 2017-03-16 | Sacrificial anode for steel reinforcement in concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/TH2017/000021 WO2018169495A1 (en) | 2017-03-16 | 2017-03-16 | Sacrificial anode for steel reinforcement in concrete |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2018169495A1 true WO2018169495A1 (en) | 2018-09-20 |
Family
ID=63522480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/TH2017/000021 WO2018169495A1 (en) | 2017-03-16 | 2017-03-16 | Sacrificial anode for steel reinforcement in concrete |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2018169495A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115304323A (en) * | 2022-07-21 | 2022-11-08 | 中交四航工程研究院有限公司 | Conductive mortar and preparation method and application thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6193857B1 (en) * | 1998-10-29 | 2001-02-27 | Foseco International Limited | Connector for use in cathodic protection and method of use |
| JP2016098596A (en) * | 2014-11-25 | 2016-05-30 | クリディエンス株式会社 | Simple repair method and simple repair structure of reinforced concrete structure without requiring cross section repair using sacrificial anode material |
| JP2017014566A (en) * | 2015-06-30 | 2017-01-19 | デンカ株式会社 | Cross-sectional repair process for concrete structure |
| JP2017014567A (en) * | 2015-06-30 | 2017-01-19 | 西日本高速道路株式会社 | Monitoring method for sacrificial anode construction method in concrete structure |
-
2017
- 2017-03-16 WO PCT/TH2017/000021 patent/WO2018169495A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6193857B1 (en) * | 1998-10-29 | 2001-02-27 | Foseco International Limited | Connector for use in cathodic protection and method of use |
| JP2016098596A (en) * | 2014-11-25 | 2016-05-30 | クリディエンス株式会社 | Simple repair method and simple repair structure of reinforced concrete structure without requiring cross section repair using sacrificial anode material |
| JP2017014566A (en) * | 2015-06-30 | 2017-01-19 | デンカ株式会社 | Cross-sectional repair process for concrete structure |
| JP2017014567A (en) * | 2015-06-30 | 2017-01-19 | 西日本高速道路株式会社 | Monitoring method for sacrificial anode construction method in concrete structure |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115304323A (en) * | 2022-07-21 | 2022-11-08 | 中交四航工程研究院有限公司 | Conductive mortar and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Goyal et al. | A review of corrosion and protection of steel in concrete | |
| US11519077B2 (en) | Galvanic anode and method of corrosion protection | |
| US9598778B2 (en) | Treatment process for concrete | |
| EP1749119B1 (en) | Sacrificial anode assembly | |
| CA2880235C (en) | Galvanic anode and method of corrosion protection | |
| US8157983B2 (en) | Composite anode for cathodic protection | |
| EP1861522B2 (en) | Treatment process for concrete | |
| Araujo et al. | Cathodic protection for concrete structures | |
| WO2018169495A1 (en) | Sacrificial anode for steel reinforcement in concrete | |
| WO2008118589A1 (en) | Composite anode for cathodic protection | |
| US20090183998A1 (en) | Activating matrix for cathodic protection | |
| Sekar et al. | Cathodic protection of steel in concrete using conductive polymer overlays | |
| Bennett | Corrosion of reinforcing steel in concrete and its prevention by cathodic protection | |
| Bennett et al. | Extending the life of concrete patch repair with chemically enhanced zinc anodes | |
| Goodwin | Next Generation Galvanic Anodes | |
| Bhuiyan et al. | Residual protection on a wharf structure following application of impressed current cathodic protection | |
| ElSafty et al. | CONCRETE REPAIR AND CATHODIC PROTECTION OF CORRODED REINFORCED CONCRETE STRUCTURE | |
| Costa | Corrosion of steel reinforcing in concrete and masonry structures | |
| Brueckner et al. | Conservation of defence heritage structures using corrosion protection techniques | |
| Yang et al. | Life extension strategy of brotherson dock wharf structures | |
| Ellingson et al. | Advancements in Galvanic Protection for Marine Structures | |
| Giorhini et al. | Galvanic Cathodic Protection System Complying With Code Based Protection Criteria | |
| Sham-sul-nisa et al. | Sacrificial Cathodic Protection Method of Reinforcement from Corrosion | |
| Oleiwi et al. | Experimental study of cathodic protection for reinforced concrete submerged in saline water | |
| PSA | 30 CATHODIC PROTECTION OF PORTCULLIS HOUSE: PSA 5-YEAR TRIAL PROVES THE SYSTEM CC MORTON PSA Specialist Services, DCES, Croydon, UK |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17901070 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 17901070 Country of ref document: EP Kind code of ref document: A1 |