JP3335153B2 - External electrode structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external electrode structure used in a method for electrochemically desalinating and / or re-alkalizing a concrete structure. The present invention relates to an external electrode structure applicable to a concrete structure.

[0002]

2. Description of the Related Art Repair of reinforced concrete and reinforced concrete structures (hereinafter collectively referred to as "concrete structures") due to corrosion of steel materials involves painting methods for concrete surfaces and section restoration (repair) methods. There is an electrochemical repair method for preventing corrosion of steel from the root by flowing an electric current from the surface of the concrete to the steel inside the concrete. As the above-mentioned electrochemical repair method, an electrolytic protection method, a desalination method, a re-alkalization method, an electrodeposition method and the like are known.

[0003] Among the above-mentioned electrochemical repairing methods, the desalination method is a method in which chloride ions in a concrete structure are corroding or possibly corroding steel materials in concrete. It is installed as a non-destructive repair method to remove outside. When chloride ions are present in a concrete structure, sea sand is used during the construction of the concrete structure.If the structure already contains chloride, seawater, snow melting agent, In such a case, the chloride ions have permeated. In such a case, the reinforcing steel rusts and expands, so that the concrete is deteriorated or destroyed. The above desalination method was developed focusing on the movement of chloride ions in the concrete structure in the direction of the anode (concrete surface). This is a construction method aimed at energizing a large current density (about 1 A / m ² ) for one to two months to take out chloride ions in the concrete out of the concrete. This method has characteristics that the applied current density is large and the processing period is relatively short.

[0004] The re-alkalization method is applied as a non-destructive repair method when carbonation of concrete occurs and the steel material in the concrete is corroded or possibly corroded. The neutralization of the concrete means that carbon dioxide and water in the air penetrate through pores and voids in the concrete, thereby causing calcium hydroxide in the concrete to be carbonated and the PH in the concrete to decrease. As a result, the reinforcing steel rusts and expands, so that the concrete is deteriorated and destroyed. In the re-alkalization method, a relatively large current density (about 1 A / m ² ) is applied between the temporary external electrode and the internal steel material in the concrete for about one week, and the alkalinity held in the temporary external electrode structure is maintained. This method aims to restore the neutralized concrete to an alkaline state by forcibly penetrating the solution into the concrete, thereby giving the concrete an anticorrosion effect.

[0005] Among the conventional electrochemical repair methods, there are various methods in the desalination method and the re-alkalization method, depending on the configuration of the external electrode structure, such as the cellulose fiber method, the panel method, and the nonwoven fabric. There is known a method using the like.

The cellulose fiber method is a method in which a cellulose fiber containing an electrolytic solution (electrolyte holding material) is sprayed on a concrete surface, and then an electrode material is attached. This method cannot be used when it is used outdoors, or when it is used near the edge of a river or coast, since the cellulose fibers (electrolyte holding material) holding the electrolyte are easily washed away.

The panel method has an external electrode structure shown in FIG. In FIG. 2, a panel 24 made of vinyl chloride, acrylic, etc.
It is attached to a concrete structure 29 via a waterproof member 28 and an adhesive with a holding member 22 such as L-shaped steel through a frame member 23 such as a square pipe. Holding material 22
Are fixed to the concrete structure 29 with a spacer 21 at a predetermined distance, and are fixed with anchor bolts 27. Electrodes 25 are located in the electrolyte 26 between the panel 24 and the concrete surface 28 and are connected to an external power supply (not shown). A valve (not shown) is provided on the external electrode structure for injecting an electrolyte and discharging gas generated by energization.
Is installed. However, in the panel method, it is difficult to safely dispose of the vinyl chloride panel, so that there is a problem in use. On the other hand, acrylic panels are expensive and easily broken, so care must be taken to prevent breakage and damage during construction. In addition, in order to install a panel on a curved surface of concrete such as a bridge pier having a cylindrical shape or an elliptical cross section, it is necessary to process a panel, a mounting member, and the like according to the curved surface. Furthermore, when installing a concrete panel having an uneven surface, it is difficult to completely block water with only a water-stopping sealing material.

[0008] The method using a non-woven fabric is a method in which a non-woven fabric and an electrode are laminated on a concrete surface, an upper surface thereof is hermetically sealed, and an external electrode structure filled with an electrolyte is provided between the non-woven fabric and the electrode. No. 11-110558). However, this method also has the same problem as the panel method when a panel is used as a sealing material. Also, when sealed with a flexible material such as a waterproof sheet,
Gas removal in electrolyte due to non-woven fabric in electrolyte,
There is a problem that circulation of the electrolyte is insufficient.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and solves the above-mentioned problems. It can be securely, easily and securely fixed to a concrete surface, and the fixing work time is short. In particular, it is an object of the present invention to provide an external electrode structure that can be applied to a concrete structure having a curved surface or an uneven surface, or a concrete structure at the edge of a wave.

[0010]

The present invention SUMMARY OF] is a concrete structure, the water stopping sealant circumferential and set, from the top of the electrode, hippopotamus
Keep the distance between the sealing material and the concrete structure constant
The covering member having a projection portion of the role spacers fixed lamination, Ri na satisfies the electrolyte solution between the covering member and the concrete surface, the electrode is
An object of the present invention is to provide an external electrode structure having a space in a portion corresponding to the projection . It is preferable to attach a slack preventing material on the covering material. The external electrode structure may be fixed to the concrete structure by covering a fastening member. It is preferable that the water-stopping sealing material is in contact with the concrete surface via an easily peelable non-land correction material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The waterproof sealing material of the present invention is provided around a place where a desalting method or a re-alkalizing method of a concrete structure is performed, and is used for holding an electrolytic solution. As a material constituting the water-stop sealing material of the present invention, butyl rubber,
It is a molded product such as foamed rubber, and among them, a butyl rubber extruded molded product is preferable from the viewpoint of flexibility, water stopping property and the like. The thickness and width of the waterproof sealing material vary depending on the concrete structure used, but the thickness is usually 1.0 to 3.0 cm, preferably 2.0 to 2.5 cm, and the width is usually 2.0 to 2.5 cm. 6.0
cm, preferably 4.0-5.5 cm. As the physical properties of the waterproof sealing material, it is necessary to have excellent alkali resistance and acid resistance.

The electrode (anode) used in the external electrode structure of the present invention may be a commonly used electrode, such as a metal or a conductive material having a low ionization tendency, such as titanium, platinum, or a metal material or a conductive material plated with them. Corrosion-resistant electrodes such as conductive resin materials. Preferably, it is a titanium electrode. The above-mentioned electrode (anode) can be used repeatedly after the work is completed. The electrodes are expanded and
Mesh processing is preferred. When the opening of the mesh is diamond-shaped, the preferred size of the opening is 70 mm × 3.
0 mm, the preferred wire diameter of the mesh is 1-2 mm
It is.

[0013] The covering material of the present invention is laminated from above the electrode via a spacer, and is used for sealing the external electrode structure and holding the electrolyte. The thickness of the covering material is preferably about 2 to 3 mm. As the material of the covering material, a material excellent in hermeticity, flexibility, chemical resistance, and strength is preferable. For example, polyethylene, polyester, ethylene-propylene-diene copolymer (EPD)
M) Coating polyester fabric, thermoplastic polyurethane and the like. Among them, a high-density polyethylene sheet such as HDPE is preferable.

The spacer may be of any type as long as it serves to keep the distance between the covering material and the concrete structure constant. The depth of the spacer is
Preferably 5 to 30 mm, more preferably 7 to 15 m
m. When the shape of the spacer is cylindrical, the diameter is preferably 5 to 30 mm, more preferably 5 to 30 mm.
It is about 20 mm. The spacing between the spacers may be any, but when using meshed electrodes,
An interval that matches the size of the mesh opening of the electrode is preferred. The spacer may be arranged as a protrusion on the covering material and integrated with the covering material. The arrangement state can be selected as appropriate, for example, in a staggered manner.

When a covering material having a projection as the spacer is used, an electrode having a space (for example, a mesh opening) in a portion corresponding to the projection may be used to separate the electrode from the concrete structure. preferable. In the external electrode structure of the present invention, when a covering material having a projection is used, the safety and ease of working on a concrete structure having a curved surface or an uneven surface or a concrete structure at the time of waving is high.

The electrolyte filled between the covering material of the external electrode structure of the present invention and the concrete surface may be a commonly used electrolyte. Water, which is the main component of the electrolytic solution,
Ordinary water such as industrial water and tap water may be used, and seawater may be used as long as the object of the present invention is not impaired. Examples of the electrolyte component contained in the electrolyte include various salts of alkali metals such as calcium, sodium, and lithium, and alkaline earth metals such as hydroxides, chlorides, and borates. Preferably, it is a saturated aqueous solution of calcium hydroxide and sodium chloride. Here, the concentration of the aqueous solution may be any as long as it can be used as an electrolytic solution.

It is preferable that a slack preventing material is attached to the outside of the covering material of the external electrode structure of the present invention. The anti-sag material helps the covering material adhere to the concrete structure and prevents deformation of the covering material, especially deformation due to water pressure. Examples of the material of the anti-sagging material include polyamides such as polyethylene, polypropylene, nylon 6, and nylon 6,6, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and cores such as aramid fiber, ultra-high-molecular polyethylene fiber, and amorphous metal fiber. The material is preferably polyethylene reinforced with aramid fiber.

The shape may be either a net or a sheet, but is preferably a net. The net may be a woven fabric or a knitted fabric, or may have a woven stitch fused thereto. The weight of the net is preferably 500-1,500 g
/ M ² . Net size is preferably 2-4c
m.

A fastening member may be provided on the covering material of the external electrode structure of the present invention. The fastening member is used to fix the external electrode structure to the concrete structure, but also serves to protect the covering material. When the fastening member is used, for example, when installing the external electrode structure of the present invention around a column such as a pier,
It can be firmly fixed without using anchor bolts, pins, nails and the like. As the shape of the fastening member,
Any material may be used as long as it does not contradict the object of the present invention. Preferably, a cloth fastening belt made of cloth such as synthetic fiber can be used as appropriate. The fastening member may be applied in any manner as long as it does not violate the purpose of the present invention, and may be fixed vertically and / or horizontally. In addition, the external electrode structure of the present invention can be fixed to a concrete structure by a fixing method using a frame member or an anchor bolt similar to the conventional method without using the above-mentioned fastening member.

The waterproof sealing material of the external electrode structure of the present invention comprises:
It is preferable that it is in contact with the concrete surface via an easily removable material for correcting unevenness. When the concrete surface to be applied is a curved surface and / or an uneven surface, the use of an easily releasable terrain correcting material is effective in preventing leakage of the electrolyte. Conventionally, polymer cement has been used as a material for correcting unevenness, but peeling from concrete is not easy,
If the ironing of the polymer cement is not carefully performed at the time of construction, water leakage occurs, and there is a problem that workability is poor. Any material can be used as the material for the non-land correction material that can be easily peeled, as long as it is easily peelable and has elasticity. For example, a special rubber-based peelable crack seal material [manufactured by Kanebo NSC Ltd. And the like. The method of applying the uneven land correction material depends on the sealing material to be used, but in the case of the crack seal material, ironing is generally applied. Here, the easy-to-peel land repair material of the present invention is:
The workability is very good because it can be brought into close contact with the construction site by simply pressing it, and can exhibit water-stopping properties.

A schematic plan view showing a longitudinal section of a preferred example of the external electrode structure of the present invention will be described below with reference to FIG. 1, but the present invention is not limited to this. As shown in FIG. 1, the external electrode structure of the present invention is a concrete structure 1
8, a waterproof sealing material 16 is provided around the portion where the desalting method or the re-alkalization method is to be performed, and the electrode 12 and the covering material 13 having a projection 19 as a spacer are laminated and fixed. The electrolyte 11 is filled between the concrete surface 13 and the concrete surface. In FIG. 1, a slack preventing member 14 is attached on the covering member 13 and a fastening member 15 is covered. In addition, the water-stop sealing material 16
It is in contact with a concrete structure 18 via an unevenness correction material 17.

In FIG. 1, the electrode 12 is located between the waterproof sealing member 16 and the concrete structure 18, and is pressed against the concrete structure 18 by the projection of the covering material 13, and Structure 1
It is preferable not to make close contact with 8. In FIG. 1, the upper portion is an opening, which functions as an inlet for the electrolytic solution and an outlet for gas generated by temperature change or reaction at the electrode portion. A valve may be appropriately provided for injecting gas and discharging gas generated by energization.

The electrochemical desalting method and / or the re-alkalization method using the external electrode structure of the present invention installed as described above are performed as follows. First, a negative electrode of a DC power supply (not shown) is connected to a conductive reinforcing material (not shown) in a concrete structure to form an internal electrode. A reinforcing bar is usually used as the conductive reinforcing material. Next, the anode of the DC power supply is connected to the electrode 12 of the external electrode structure 10 according to the present invention, and current is applied. The energizing condition of the DC power source when energizing between the anode and the negative electrode is that the electric current is preferably the concrete surface area 1
m ² is 1 amperes per. When the current is low, the desalting effect and the re-alkalization effect are low, and a long-time energization is required. On the other hand, when the current is high, the amount of generated hydrogen around the conductive reinforcing material as the negative electrode increases, and hydrogen embrittlement of iron occurs. Further, the voltage is preferably 10 to 40 volts, and more preferably 30 to 40 volts. If it is less than 10 volts, the desalting effect and the re-alkalization effect are low, and a long-time energization is required. On the other hand, if it exceeds 40 volts, the danger increases. The energizing time of the DC power supply can be appropriately selected depending on the amount of salt contained in the concrete and the degree of neutralization.

[0024]

EXAMPLES The present invention will now be described more specifically with reference to examples, but the present invention is not limited to the following examples. In addition,% in an Example is a weight% unless there is particular notice.

EXAMPLE The external electrode structure of the present invention was installed on a concrete structure as shown in FIG. Waterproof sealing materials, electrodes,
The covering material with a projection, a slack preventing material, a fastening member, a material for correcting unevenness, and an electrolytic solution are shown below.

Waterproof sealing material; thickness 20 mm, width 50 mm
Butyl rubber extruded product electrode; titanium plate expanded and meshed (rhombus opening 70 mm × 30
mm) covering material with electrode projections; depth 10m
m, 2-3 mm thick high-density polyethylene sheet (HD
PE) spacing between protrusions 16.5 × 20 mm (K.
Carbofor NAP sheet manufactured by F.C.) Anti-sag material; aramid fiber reinforced polyethylene net of 4,500 denier (net weight 1,100 g / m ² ,
Scale 2.8 × 2.6cm, Maeda Kosen Co., Ltd.) Tightening member; Cloth packing belt Non-land correction material; Special rubber-based peelable crack seal material [Kanebo NS Co., Ltd.] Electrolyte ; Saturated aqueous solution of calcium hydroxide

[0027] The electrodes made by the external electrode structure to the anode of a DC power supply, and connect the reinforcement of the internal concrete negative electrode of the DC power source, the concrete surface 1 m ² per ampere 25
A current of ± 15 V was applied. After turning on electricity for 2 months,
A significant decrease in the amount of chloride in concrete was observed.

[0028]

The external electrode structure of the present invention is safe, easy,
The external electrode can be securely fixed to the concrete surface, and the fixing work time is shortened. In particular, the present invention can be applied to a concrete structure having a conventionally difficult surface such as a concrete structure having a curved surface or an uneven surface or a wavy concrete structure. Further, according to the present invention, when the fastening member is covered on the covering material, it is not necessary to use anchor bolts or the like which are conventionally used for fixing the external electrode structure. Not affected by waves. Also,
The fixing work is easy and the cost is reduced. As described above, the external electrode structure of the present invention is very useful for the electrochemical desalination method and / or the re-alkalization method of a concrete structure, and can shorten the construction period and reduce the construction cost.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a longitudinal section of a preferred example of an external electrode structure of the present invention.

FIG. 2 is a schematic plan view showing a longitudinal section of an example of an external electrode structure used in a conventional method (panel construction method).

[Description of Signs] 10 External electrode structure 11 Electrolyte solution 12 Electrode 13 Covering material with projection 14 Anti-slack material 15 Clamping member 16 Waterproof seal material 17 Uneven correction material 20 External electrode structure 21 Spacer 24 Panel 28 Waterproof seal Lumber

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shihibe Nishiura 3-7 Horina, Arazudo-cho, Katsuyama-shi, Fukui Prefecture (72) Inventor Hiroshi Enami 43-28-3 Shimotsuke, Ono-shi, Fukui Examiner Takeshi Inami (56) References JP-A-8-40783 (JP, A) JP-A-7-315957 (JP, A) JP-A-8-119768 (JP, A) JP-A-3-93681 (JP, A) Kaihei 8-319182 (JP, A) Registered utility model 3066045 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E04G 23/02 C04B 41/60

Claims (4)

(57) [Claims] 1. A watertight seal material is provided around a concrete structure, and a covering material and concrete are placed over the electrode.
A spacer that plays a role in keeping the distance from the structure constant
Laminate and fix the covering material with all the protrusions ,
The covering material and Ri Na meets electrolyte between the concrete surface, the electrode portions corresponding to the protrusion portion
An external electrode structure having space . 2. The external electrode structure according to claim 1, wherein a slack preventing material is attached to the outside of the covering material. 3. The external electrode structure according to claim 1, wherein the external electrode structure is fixed to the concrete structure by covering a fastening member. 4. The concrete structure according to claim 1, wherein said water-stopping sealing material is in contact with the concrete surface via a non-repairable material which is easy to peel off.
The external electrode structure according to claim 1.