Cathode protection method and apparatus for reinforced concrete structure and composite structure and processing method for reinforced concrete structure

Abstract

A cathode protection method of embedded CFRP anode for reinforced concrete structure includes the following steps. Provide a preformed groove with a predetermined shape and size in a surface of a protection area of a reinforced concrete body, and remove dust in the preformed groove. Provide a CFRP member on the surface of the protection area of the reinforced concrete body. Coat an electrical conductive adhesive material between side surfaces of the reinforcing column of the CFRP member and the preformed groove and between the reinforcing plate and the reinforced concrete body. Connect the CFRP member with a positive electrode of an external DC power supply and the steel reinforcing element with a negative electrode of the external DC power supply.

Claims

1. A cathode protection method for a reinforced concrete structure, comprising the steps of: (a) embedding a plurality of steel reinforcing elements in a surface of a protection area of a reinforced concrete body, and electrically connecting said steel reinforcing elements with each other in said protection area; (b) treating said surface of said protection area of said reinforced concrete body by the steps of polishing and smoothing said surface of said protection area of said reinforced concrete body, applying an adhesive on any uneven and non-flat area of said reinforced concrete body, removing air mixed in said adhesive in said protection area, and removing excessive adhesive in said protection area; (c) forming a preformed groove with a predetermined shape and size on said surface of said protection area of said reinforced concrete body, and removing dust in said preformed groove; (d) forming a CFRP member which comprises a reinforcing column and a reinforcing plate integrally connected with said reinforcing column, wherein said reinforcing column is sized and shaped matching with said preformed groove; (e) applying an electrically conductive adhesive material on said CFRP member and placing said CFRP member on said protection area of said reinforced concrete body at a position that said reinforcing column is inserted into said preformed groove and said reinforcing plate covers said surface of said protection area of said reinforced concrete body, wherein via said electrically conductive adhesive material, said reinforcing column is adhered in said preformed groove and said reinforcing plate is adhered on said surface of said protection area of said reinforced concrete body so as to embed said reinforcing column in said preformed groove of said reinforced concrete body and to cover said preformed groove by said reinforcing plate; and (f) electrically connecting an external DC power supply with said CFRP member and said steel reinforcing elements in said reinforced concrete body by electrically connecting said CFRP member with a positive electrode of said external DC power supply and electrically connecting said steel reinforcing elements with a negative electrode of said external DC power supply, wherein said steel reinforcing elements and said electrically conductive adhesive material are electrically connected via said reinforced concrete body, said CFRP member and said external DC power supply to form a closed electrical conductive circuit.

2. The method, as recited in claim 1, wherein the step (e) further comprises the steps of: (e.1) coating said electrically conductive adhesive material on side surfaces of said reinforcing column and said preformed groove to adhere said reinforcing column in said preformed groove; and (e.2) coating said electrically conductive adhesive material between said reinforcing plate and said surface of said protection area of said reinforced concrete body to adhere said reinforcing plate on said surface of said protection area of said reinforced concrete body.

3. The method, as recited in claim 1, wherein said electrically conductive adhesive material is cement grout not only adhering said CFRP member on said surface of said protection area of said reinforced concrete body but also filling cracks in said protection area of said reinforced concrete body.

4. The method, as recited in claim 2, wherein said electrically conductive adhesive material is cement grout not only adhering said CFRP member on said surface of said protection area of said reinforced concrete body but also filling cracks in said protection area of said reinforced concrete body.

5. The method, as recited in claim 1, wherein said electrically conductive adhesive material is epoxy glue with graphite powder.

6. The method, as recited in claim 2, wherein said electrically conductive adhesive material is epoxy glue with graphite powder.

7. A cathode protection apparatus for a reinforced concrete structure, comprising: a reinforced concrete body defining a protection area and having a preformed groove indented on a surface of said protection area; a plurality of steel reinforcing elements embedded in said protection area of said reinforced concrete body, wherein said steel reinforcing elements are electrically connected with each other; at least a CFRP member comprising a reinforcing column and a reinforcing plate integrally extended with said reinforcing column, wherein said reinforcing column which is shaped and sized matching with said preformed groove, wherein said CFRP member is placed on said protection area of said reinforced concrete body at a position that said reinforcing column is inserted into said preformed groove and said reinforcing plate covers on said surface of said protection area of said reinforced concrete body; an electrically conductive adhesive material applied on said CFRP member to adhere said reinforcing column in said preformed groove and to adhere said reinforcing plate on said surface of said protection area of said reinforced concrete body so as to embed said reinforcing column in said preformed groove of said reinforced concrete body and to cover said preformed groove by said reinforcing plate; and an external DC power supply electrically connecting with said CFRP member and said steel reinforcing elements in said reinforced concrete body, wherein said CFRP member is electrically connected with a positive electrode of said external DC power supply and said steel reinforcing elements are electrically connected with a negative electrode of said external DC power supply, wherein said steel reinforcing elements and said electrically conductive adhesive material are electrically connected via said reinforced concrete body, said CFRP member and said external DC power supply to form a closed electrical conductive circuit.

8. The cathode protection apparatus, as recited in claim 7, wherein said electrically conductive adhesive material is coated on side surfaces of said reinforcing column and said preformed groove to adhere said reinforcing column in said preformed groove, and is coated between said reinforcing plate and said surface of said protection area of said reinforced concrete body to adhere said reinforcing plate on said surface of said protection area of said reinforced concrete body.

9. The cathode protection apparatus, as recited in claim 7, wherein said electrically conductive adhesive material is cement grout not only adhering said CFRP member on said surface of said protection area of said reinforced concrete body but also filling cracks in said protection area of said reinforced concrete body.

10. The cathode protection apparatus, as recited in claim 8, wherein said electrically conductive adhesive material is cement grout not only adhering said CFRP member on said surface of said protection area of said reinforced concrete body but also filling cracks in said protection area of said reinforced concrete body.

11. The cathode protection apparatus, as recited in claim 7, wherein said electrically conductive adhesive material is epoxy glue with graphite powder.

12. The cathode protection apparatus, as recited in claim 8, wherein said electrically conductive adhesive material is epoxy glue with graphite powder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is structural perspective view of a cathode protection apparatus of embedded CFRP anode for a reinforced concrete structure according to a preferred embodiment of the present invention.

(2) FIG. 2 is a block diagram of a cathode protection method of embedded CFRP anode for the reinforced concrete structure according to the above preferred embodiment of the present invention.

(3) FIG. 3 is a structural perspective view of a composite structure for reinforced concrete structure with automatic cathode protection CFRP structure according to a second preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(4) The following description is disclosed to enable any person skilled in the art to make and use the present invention. Preferred embodiments are provided in the following description only as examples and modifications will be apparent to those skilled in the art. The general principles defined in the following description would be applied to other embodiments, alternatives, modifications, equivalents, and applications without departing from the spirit and scope of the present invention.

(5) Referring to FIG. 1 of the drawings, a cathode protection apparatus of embedded CFRP anode for reinforced concrete structure according to a preferred embodiment of the present invention is illustrated, wherein the cathode protection apparatus of embedded CFRP anode for reinforced concrete structure comprises a plurality of steels reinforcing elements 4 embedded in a concrete body 3, (for example, two steel reinforcing elements are shown steel reinforcing element in FIG. 1), wherein each of the steel reinforcing elements is electrically connected together by conductive wires. The cathode protection apparatus of embedded CFRP anode for reinforced concrete structure further comprises at least a CFRP member 1, wherein the concrete 3 is a reinforced concrete body 3 having a preformed groove 31 indentedly provided therein and defining adjacent side surfaces thereon adjacent to the preformed groove 31. The shape and size of the preformed groove 31 and the substantial number of such preformed groove are determined according to the requirement of the cathode protection.

(6) The CFRP member 1 comprises a reinforcing column 11 and a reinforcing plate 12 integrally connected with the reinforcing column 11, wherein the reinforcing column 11 is shaped and sized to match with and insert in the preformed groove and the reinforcing plate 12 is affixed to the adjacent side surfaces of the protection area of reinforced concrete body 3 respectively via electrically conductive adhesive material 2. Ire other words, the reinforcing column 11 and the reinforcing plate 12 of the CFRP member 1 is connected with preformed groove 31 and the adjacent side surfaces of the reinforcing concrete body by means of the adhesive material 2 so as to reduce a distance between the CFRP member and the steel reinforcing elements in the reinforcing concrete body 1, so that the resistance therebetween is decreased accordingly and thus rendering the protective current thereof being more uniformly and evenly.

(7) In substantial application, the adhesive material is required to meet the requirements of providing electrical conductivity and enabling the CFRP rigidly affixed on the surface of the concrete. For example, the adhesive material 2 can be cement grout, such as inorganic cementations materials, or conductive particles, such as epoxy glue with graphite powder that can achieve the above requirements. Preferably, according to the present invention, the cement grout is used as the adhesive material 2 that can adhere to the surfaces of the CFRP member 1. It not only has a really high strength and it can also connect the CFRP member with the concrete that can substantially increase the stability, as a whole, for the application of the cathode protection method of embedded CFRP anode for the reinforced concrete structure, wherein the preferred thickness of the adhesive material 2 is about 3 mm.

(8) The CFRP member 1 is connected to a positive electrode of an external direct current (DC) power supply (not shown in Figures), and the steel reinforcing element 4 is connected to a negative electrode of the external power supply, wherein the steel reinforcing elements 4 is connected with the CFRP member 1 via the adhesive material 2 and the concrete 3 to form a close electrical conductive circuit.

(9) The carbon fiber reinforced polymer (CFRP) material not only has excellent dynamic property. Its essential element, carbon fiber, has good electrical conductivity and its electrode potential is closed to the electrochemical property of the noble metal. Therefore, in the above described apparatus of the present invention, the using of the CFRP member 1 as the cathode of the electric current to assist the anode can adequately utilize its dynamic performance and electrochemical property. It provides cathode protection and technical performance while considering the structural reinforcement. In addition, the cost of using CFRP material is cheaper than cathode made of mixture of metal and titanium oxide so that the cost of the present invention is reduced. Also, it can be various sectional forms, rendering easy utilization in application.

(10) Preferably, when the adhesive material is cement grout, the surface contact between the adhesive material and the CFRP is ensured and its thickness adhesive material is suggested to be about 3 mm.

(11) In the above described apparatus of the present invention, the number of the steel reinforcing elements may be plenty according to different areas needed to be protected. The steel reinforcing elements are required to be connected with each other by electrical conductive wires, wherein their electric conductivity must be tested to ensure the steels reinforcing elements within the concrete structure area can be well protected.

(12) It is worth mentioning that the reinforced concrete structure of the present invention is not limited to rectangular structure as shown in FIG. 1. It can be other structures and shapes, such as cylindrical concrete, etc.

(13) According to the embedded CFRP anode for a reinforced concrete structure and apparatus described above, a cathode protection method for embedded CFRP anode for a reinforced concrete structure is provided, as shown in FIG. 2, wherein the method comprises the steps of:

(14) S1. Provide a preformed groove 31 with a predetermined shape and size in a protection area of a reinforced concrete body 3, and remove dust in the preformed groove.

(15) Before the step S1, in order to enable the concrete within the protection area can become continuous electrolyte, it is required to remove any loose concrete within the protection area of the reinforced concrete body 3, to explode the firm and solid portion, to polish and smoothen to flat and clean, to add adhesive material to any uneven and non-flat area of the concrete, and to squeeze out air within any area mixed with adhesive material, and to remove the excessive adhesive material.

(16) S2. Provide at least a CFRP member on the respective surface of the protection area of the reinforced concrete body, wherein the CFRP member includes at least a reinforcing column 11 shaped and sized with respect to the preformed groove 31 and at least a reinforcing plate 12 integrally connected with the reinforcing column 1 and affixed on the portion adjacent to the preformed groove 31 of the surface of the protection area of the reinforced concrete body 3.

(17) That is the CFRP member 1 is connect to the reinforced concrete body 3, wherein the CFRP member 1 comprises the reinforcing column 11 and a reinforcing plate 12 integrally connected to the reinforcing column 11, wherein the reinforcing column 11 is embedded and inserted in the indented preformed groove 31 while the reinforcing plate 12 is a CFRP plate affixed to the adjacent side surfaces in the protection area of the reinforced concrete body.

(18) S3. Coat an adhesive material 2 with electrical conductive ability on side surfaces of the reinforcing column 11 and the preformed groove 31 of the reinforced concrete body 3 to be connected with each other and between the reinforcing plate 12 and the reinforcing concrete body 3. Embed the reinforcing column 11 in the preformed groove 31 of the reinforced concrete body 3 and connect the reinforcing plate 12 with the reinforced concrete body 3.

(19) That is to coat the adhesive material 2 between the CFRP member 1 and the reinforced concrete body 3. In other words, the adhesive material 2 is applied between the reinforcing column 11 and the preformed groove 31 and between the reinforcing plate 12 and the reinforced concrete body 1 so as to adhere the reinforcing column 11 in the preformed groove 31 and the reinforcing plate 12 with the reinforcing concrete body 3 in order to connect CFRP member 1 with reinforced concrete body 3.

(20) S4. Connect the CFRP member 1 with a positive electrode of an external DC power supply, and connect the steel reinforcing elements with a negative electrode of the external DC power supply, so that the steel reinforcing elements 4 and the adhesive material 2 are electrically connected via the concrete of the reinforced concrete body 3 to form a closed electric conductive circuit.

(21) In the step S4, if the number of the of the steel reinforcing element within the protection area is more than one, all the steel reinforcing elements 5 within the protection area must be electrically connected with each other, wherein the electrical conductivity between the steel reinforcing elements 4 must be examined and ensured, as well as the electrical conductivity between the reinforced concrete body 3 and the CFRP member 1 must also be examined and ensured, so as to ensure the entire circuit can transmit cathode protective current.

(22) The adhesive material 2 is required to have electrical conductivity and its strength must be strong enough. Preferably, the adhesive material 2 used in the present method is cement grout. In a preferred embodiment, the cement grout is needed to fill the cracks in the concrete to ensure the concrete becomes a continuous electrolyte.

(23) The present invention provides a cathode protection method of embedded CFRP anode for reinforced concrete structure and apparatus thereof, wherein the apparatus utilizes the more cost effective CFRP material as auxiliary anode to substitute the conventional mixture of metal and titanium oxide. In addition, the present invention utilizes adhesive material with electrical conductivity and larger strength to connect the steel reinforcing elements and the CFRP material, so as to achieve ideal protection while reducing the cost and enhancing the stability of the protection apparatus. The using of the column shaped section for the CFRP member substantially reduces the distance between the CFRP member and the steel reinforcing elements as well as the resistance therebetween, so as to provide a more even distribution of the protective current in the concrete structure and achieve a better protection effect.

(24) Referring to FIG. 3 of the drawings, a composite structure for reinforced concrete structure with automatic cathode protection CFRP structure according to a second preferred embodiment of the present invention is illustrated, wherein the composite structure comprises two structural bodies, which are a reinforced concrete body and cathode protection body.

(25) The reinforced concrete body comprises a concrete 3*, a plurality of steel reinforcing elements 2*, a CFRP pipe 1*, wherein the steel reinforcing elements 2* are embedded within the concrete 3*, wherein the CFRP pipe 1* is arranged on a surface of the reinforced concrete body, and is electrically connected with the steel reinforcing element 2* via the concrete 3*. And, an external power supply 5* is connected to at least one steel reinforcing elements 2* of the reinforced concrete body and the CFRP pipe 1* for impressing current to the steel reinforcing element 2*. In the present invention, the reinforced concrete body is integrally mounted with the CFRP pipe 1*.

(26) The CFRP pipe 1* is a composite material mixing with different fibers or matrix materials, such as carbon fiber and glass fiber (a fiber-reinforced composite material).

(27) The present invention utilizes the advantages of the excellent dynamic, and electrochemical properties of the CFRP, the CFRP is not only used to be a reinforcing material, but also can be used to an auxiliary anode. Therefore, the structural reinforcement system and the cathode protection system are integrated to be one structural system, According to the above described composite structure, even if the steel reinforcing elements 2* are embedded into a concrete with rich of corrective media, such as sea sand type concrete, all steel reinforcing elements 2* therein are well protected. The steel reinforcing elements 2*the concrete 3*the CFRP pipe 1* (connected by a conductive wire 6*) form a complete conductive circuit to smoothly transmit the cathode protection current. The present invention utilizes an external power supply 5* with a constant output current or voltage to impress weak current to the steel reinforcing elements 2* to achieve the cathode protection, such that the cathode current is applied to the steel reinforcing elements 2* for forcing the potential of the steel reinforcing elements 2* in the corrosion-free area so as to reach the protection purpose for the steel reinforcing element 2*. And, the external power supply 5* is a DC power supply providing a constant output current and voltage.

(28) According to the above second preferred embodiment of the present invention, the reinforced concrete body can be a circular concrete column or a rectangular structure, and FIG. 3 shows the cylindrical reinforced concrete body structure. Referring to FIG. 3 of the drawings, a plurality of steel reinforcing elements 2* are arranged around a peripheral of the concrete 3*, and each of the adjacent steel reinforcing elements 2* is electrically connected, so the electrically-connected steel reinforcing elements 2*, the concrete 3*, and the CFRP pipe 1* are integrally mounted with each other so as to omit the installation process for the cathode protection body. In other words, the external powers supply 5* of the cathode protection body is directly connected to the reinforced concrete body. For example, the external power supply 5* has a negative electrode connecting to any of the steel reinforcing elements 2*, and a positive electrode connecting to the CFRP pipe 1*, so as to from the cathode protection body.

(29) The CFRP pipe 1* is a reinforcing material and an auxiliary anode in the present invention, and the CFRP member must have a reliable dynamic property, electrochemical properties and durability properties under a long term usage, environmental factors and the interaction of the protection current interaction, so as to achieve structural reinforcement and cathode protection.

(30) In the above described apparatus of the present invention, the number of the steel reinforcing elements 2* must be at least one. When the number of the steel reinforcing elements 2* is larger than one, each of the steel reinforcing elements 2* is required to be connected with each other by an electrical conductive wire 4*, wherein their electric conductivity must be tested. The number of the steel reinforcing elements 2* is not limited, which can be three, four, five, or other number thereof.

(31) The carbon fiber reinforced polymer (CFRP) has the advantages of light in weight, high in strength, high in modulus, and having good corrosion resistance, so CFRP is a well-known structural reinforcing material. Actually, including the well-known dynamic properties of CFRP, its essential element, carbon fibers, has good electrochemical properties, which has good electrical conductivity and the electrode potential is closed to the electrochemical property of the noble metal. Therefore, the electrochemical properties of the CFRP can be applied to the auxiliary anode of the impressed current cathode protection system for the reinforced concrete structures.

(32) Furthermore, according to the dynamic properties and electrochemical properties of CFRP, a composite structure having cathode protection and steel reinforcing element protection function is provided. That is to say, the CFRP not only has advantages in the composite structure, but also can be an auxiliary anode in the impressed current cathode protection system. The present invention can achieve a purpose of achieving a structural reinforcement and cathode protection function in the same structure, and the CFRP is an auxiliary anode to eliminate to install a control system and an investigation system.

(33) A processing method for reinforced concrete structure with automatic cathode protection CFRP structure comprises steps of:

(34) A. integrally mounting a reinforced concrete body with a CFRP member 1*:

(35) B. mounting the CFRP member 1* on a surface of a reinforcing region of the reinforced concrete body;

(36) C. embedding at least one steel reinforcing elements 2* around an inner peripheral of the reinforced concrete body; and

(37) D. connecting an external power supply 5* to the CFRP member 1* for impressing current to the steel reinforcing elements 2*.

(38) Moreover, the CFRP member 1* is a composite material, which mixes with different fibers or matrix materials.

(39) The present invention provides a composite structure and method for reinforced concrete structure with cathode protection CFRP structure, wherein the present invention provides a cathode protection, and the steel reinforcing elements 2* within the concrete 3* are impressed by a weak current via the CFRP materials so as to achieve the protection purposes, so the corrosion of the steel reinforcing elements 2* within the sand concrete has been actively prevented. And, the CFRP has dual-functions of the structural reinforcement and the cathode protection. While present invention is applied to the reinforced concrete structure, the steel reinforcing elements 2* can be well-protected under rich of corrective media within the concrete and under harmful external working environment. In addition, the present invention provides a stable output current so as to omit the conventional control and investigation system and simplify the configuration of the present invention. At the same time, the CFRP member 1*, the concrete 3*, and the steel reinforcing elements 2* are integrally mounted to be a whole unit so as to omit the installation process of the cathode protection body and improve the efficiency of the construction.

(40) One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.

(41) It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.