JP7368068B2 - Manufacturing method of repaired structure - Google Patents

Description

The present invention relates to a crack repair material composition and a crack repair method.

For example, in concrete structures, cracks may occur in the concrete frame due to expansion and contraction of the concrete frame due to changes in environmental temperature.
As a method for repairing cracks, there is a method of injecting a repair material such as epoxy or cement into the crack (for example, see Patent Document 1).

Japanese Patent Application Publication No. 11-139858

However, in the case of structures containing metal reinforcing materials, such as reinforced concrete structures, it is sometimes difficult to increase the durability of the structure using the above-mentioned repair materials.

One aspect of the present invention aims to provide a crack repair material composition and a crack repair method that can enhance the durability of a structure containing a metal reinforcing material.

One aspect of the present invention provides a crack repair material composition containing an epoxy resin and a rust inhibitor.

Preferably, the rust inhibitor includes mineral oil, sorbitan fatty acid ester, and petroleum sulfonate.

Another aspect of the present invention provides a crack repair method in which a crack repair material containing an epoxy resin and a rust preventive agent is injected into cracks in a structure containing metal reinforcement.

In the crack repair method, a plurality of crack repair materials having different viscosities at the time of preparation are prepared, a first crack repair material among the plurality of crack repair materials is injected into the crack, and then the plurality of crack repair materials are injected into the crack. A method may be adopted in which a second crack repair material having a higher viscosity than the first crack repair material among the repair materials is injected into the crack.

It is preferable that the amount of the rust preventive agent in the first crack repair material is greater than the amount of the rust preventive agent in the second crack repair material.

According to one aspect of the present invention, a crack repair material composition and a crack repair method capable of increasing the durability of a structure containing a metal reinforcing material are provided.

It is a perspective view showing an example of a structure containing metal reinforcing material to which the crack repair method of the embodiment can be applied. It is a perspective view explaining the repair method by a 1st embodiment. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure. It is a sectional view explaining the repair method by a 1st embodiment. It is a sectional view explaining a repair method following the previous figure. It is a sectional view explaining a repair method following the previous figure. It is a sectional view explaining a repair method following the previous figure. It is a perspective view explaining the repair method by a 2nd embodiment. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure. It is a perspective view explaining the repair method following the previous figure.

Hereinafter, a crack repair material composition and a crack repair method according to embodiments will be described in detail with reference to the drawings.

[Structures with metal reinforcement]
FIG. 1 is a perspective view showing an example of a structure containing metal reinforcing material to which the crack repair method of the embodiment can be applied.
The reinforced concrete structure 10 shown in FIG. 1 is a reinforced concrete (RC) structure, and is a specific example of a structure containing metal reinforcement. The reinforced concrete structure 10 is a wall section erected on a base 11. The reinforced concrete structure 10 includes internal reinforcing bars 12 and a concrete frame 13. The internal reinforcing bars 12 are buried inside the concrete frame 13. The internal reinforcing bars 12 include vertical reinforcing bars 14 extending in the height direction of the reinforced concrete structure 10 and horizontal reinforcing bars 15 extending in a direction orthogonal to the longitudinal reinforcing bars 14. Internal reinforcing bars 12 are an example of metal reinforcement.

Cracks 20 (cracks) are formed in the concrete frame 13 of the reinforced concrete structure 10. The crack 20 is formed from the first main surface 10a of the reinforced concrete structure 10 toward the inside of the reinforced concrete structure 10. The cracks 20 occur, for example, when the concrete body 13 expands and contracts due to changes in environmental temperature, changes in the water content of the concrete body 13, and the like. For example, the cracks 20 are formed when the concrete body 13 is divided by tensile stress caused by expansion and contraction of the concrete body 13. The cracks 20 include defects and defects formed in the concrete body 13. The crack 20 reaches, for example, the internal reinforcing bar 12.

[Crack repair material composition]
The crack repair material composition of the embodiment contains an epoxy resin and a rust preventive.
The epoxy resin may be a two-part type or a one-part type. A two-component epoxy resin contains a base resin and a curing agent. The base agent is produced, for example, by polymerizing bisphenol A and epichlorohydrin. The base agent has two or more epoxy groups in one molecule. The base agent includes, for example, a phenol novolac type epoxy resin, n-butyl-2,3-epoxypropyl ether, and a reactive diluent. The viscosity of the reactive diluent is lower than the viscosity at the time of preparation of the epoxy resin (the viscosity immediately after mixing the base resin and the curing agent). The main ingredient may include silica.

Examples of the curing agent include amine compounds, organic acids, acid anhydrides, and the like. Examples of the amine compound include tetraethylenepentamine, diethylenetriamine, modified aliphatic polyamine, aliphatic polyamine, metaxylylene diamine, and polyamide amine. These amine compounds may be used alone or in combination of two or more.

The curing agent may include phenols. Examples of phenols include 2,4-di-tert-butylphenol, phenol, and cresol. These phenols may be used alone or in combination of two or more.

Examples of rust preventives include mineral oils, esters, petroleum sulfonates, carboxylic acids, nitrogen compounds, phosphates, thiophosphates, and the like.
Examples of the mineral oil include paraffinic mineral oil and naphthenic mineral oil. Examples of esters include sorbitan fatty acid ester and pentaerythritol monooleate. Examples of sorbitan fatty acid esters include sorbitan monoisostearate and sorbitan monooleate. Examples of petroleum sulfonates include calcium petroleum sulfonate, sodium petroleum sulfonate, barium petroleum sulfonate, and the like. Examples of the carboxylic acids include alkali metal salts of aliphatic carboxylic acids, alkali metal salts of alkenylsuccinates, and alkali metal salts of aromatic carboxylic acids. Examples of the nitrogen compound include dicyclohexylammonium nitrite and diisopropylammonium nitrite.

Rust is caused, for example, by oxidation reactions caused by electrical and chemical effects on metal surfaces. It can be assumed that the rust preventive agent suppresses the occurrence of rust, for example, by the following actions. The rust preventive agent adsorbs to the surface of the target metal (for example, internal reinforcing bars 12), suppresses adsorption of water and oxygen, and makes it difficult to ionize the metal. Therefore, the rust preventive agent can reduce the reactivity of the metal (for example, the internal reinforcing bars 12) and suppress the occurrence of rust.

It is preferable that the rust preventive agent contains at least mineral oil, sorbitan fatty acid ester, and petroleum sulfonate. Thereby, the rust prevention effect in reinforced concrete structures can be enhanced.
The amount of rust preventive added to the epoxy resin can be, for example, 0.5 to 10 parts by weight (preferably 0.5 to 5 parts by weight) per 100 parts by weight of the epoxy resin.
It is preferable to mix the rust preventive agent with the curing agent in advance. This facilitates the work of preparing the crack repair material at the construction site.

[Crack repair method] (1st embodiment)
2 to 6 are perspective views illustrating a crack repair method (hereinafter sometimes simply referred to as a repair method) according to the first embodiment. 7 to 10 are cross-sectional views illustrating the repair method according to the first embodiment. Hereinafter, a crack repair method according to an embodiment will be described with reference to FIGS. 2 to 10.

(Cleaning process)
As shown in FIG. 2, on the surface (first main surface 10a) of the reinforced concrete structure 10, a band-shaped area including the crack 20 (a band-shaped area along the crack 20) is cleaned to remove foreign matter.

(Sealing process)
As shown in FIG. 3, a temporary sealing material 21 is applied to the band-shaped region along the cracks 20. As shown in FIG. The crack 20 is covered in the area where the temporary sealing material 21 is applied, thereby closing the opening of the crack 20. As shown in FIGS. 3 and 7, the temporary sealing material 21 is not applied to the injection site 22, which is a part of the band-shaped region. At the injection site 22, a crack repair material is injected into the crack 20 in a process described below. There may be one injection site 22, or there may be multiple injection sites. The plurality of injection points 22 are secured at intervals in the direction along the crack 20.

As shown in FIGS. 4 and 8, an injection device 23 for injecting the crack repair material is attached to the injection site 22. The injection device 23 includes a mounting seat 25 and an injection conduit 26. The mounting seat 25 is formed into a disk shape. The injection conduit 26 extends from one surface of the mounting seat 25 in a direction perpendicular to the mounting seat 25. The injection conduit 26 and the mounting seat 25 have an internal flow path through which the crack repair material flows. The mounting seat 25 of the injection device 23 is adhered to the first main surface 10a with a temporary sealing material 21.
As shown in FIGS. 5 and 6, a pressure tank 28 is attached to the injection line 26 via a branch line 27.

(Injection process)
The crack repair material composition described above is prepared. When using a two-component epoxy resin, the base resin and curing agent are mixed immediately before injection into the crack 20 to obtain a crack repair material composition. An epoxy resin is produced by mixing the base resin and the curing agent. A rust preventive agent is blended into the crack repair material composition. When a rust preventive agent is mixed in advance with the hardening agent, a crack repair material composition containing an epoxy resin and a rust preventive agent can be obtained by mixing the base agent and the hardening agent.

As shown in FIG. 5, the crack repair material composition is filled into the reservoir 30a of the injection pump 30 as the crack repair material 31. The crack repair material 31 is injected into the crack 20 through the injection device 23 by the injection pump 30 . As shown in FIG. 9, the crack repair material 31 enters the crack 20 through the internal channel of the injection device 23. As shown in FIG. The crack repair material 31 is distributed throughout the crack 20, and a portion reaches the internal reinforcing bars 12. A portion of the crack repair material 31 covers the surface of the internal reinforcing bars 12. The rust preventive agent contained in the crack repair material 31 acts on the internal reinforcing bars 12.
As shown in FIG. 5, the temporary sealing material 21 prevents the crack repair material 31 from overflowing from the crack 20.

As shown in FIG. 6, after the crack repair material 31 is injected into the crack 20 through the injection device 23, the tip of the injection conduit 26 is closed. When the crack repair material 31 is injected, a portion of the crack repair material 31 flows into the pressure tank 28 . As a result, the internal pressure of the pressure tank 28 increases, so that the crack repair material 31 in the pressure tank 28 is injected into the crack 20 through the injection pipe 26 at a stable flow rate even after the injection pipe 26 is closed. By leaving it for a predetermined period of time, the crack repair material 31 within the crack 20 hardens.
As shown in FIG. 10, after the crack repair material 31 has hardened, the temporary sealing material 21 and the injection device 23 are removed.

Since the crack repair material composition contains a rust preventive agent, the rust preventive agent can act on the internal reinforcing bars 12 within the crack 20 . Therefore, the occurrence of rust in the internal reinforcing bars 12 can be suppressed. Therefore, the durability of the reinforced concrete structure 10 can be improved.

Since the crack repair method uses a crack repair material composition containing a rust preventive agent, the rust preventive agent can act on the internal reinforcing bars 12 within the crack 20. Therefore, the occurrence of rust in the internal reinforcing bars 12 can be suppressed. Therefore, the durability of the reinforced concrete structure 10 can be improved.

[Crack repair method] (Second embodiment)
Next, a crack repair method according to the second embodiment will be explained. In the crack repair method of the second embodiment, a plurality of crack repair materials having different viscosities at the time of preparation (viscosity immediately after mixing the main agent and the curing agent) are used. For example, three crack repair materials (first to third crack repair materials) having different viscosities when prepared can be used. The second crack repair material has a higher viscosity than the first crack repair material. The third crack repair material has a higher viscosity than the second crack repair material.

The viscosity of the crack repair material can be adjusted by adjusting the amount of the reactive diluent in the main ingredient. For example, by increasing the amount of reactive diluent, the viscosity of the crack repair material can be lowered. By reducing the amount of reactive diluent added, the viscosity of the crack repair material can be increased. It is preferable that the amount of the reactive diluent in the main ingredient of the second crack repair material is smaller than that of the first crack repair material. It is preferable that the third crack repair material has a smaller amount of reactive diluent in the main ingredient than the second crack repair material.

The viscosity when preparing the first crack repair material may be, for example, 100 to 500 mPa·s (23° C.). The viscosity when preparing the second crack repair material may be, for example, 440 to 840 mPa·s (23° C.). The viscosity when preparing the third crack repair material may be, for example, 5000 to 15000 mPa·s (23° C.).

In the curing agent of the second crack repair material, the amine compound may include tetraethylenepentamine. As the curing agent of the second crack repair material, 2,4-di-tert-butylphenol may be used as a phenol.

It is preferable that the first crack repair material contains a larger amount (or content) of the rust preventive agent than the second crack repair material. The second crack repair material may have a larger amount (or content) of the rust preventive agent than the third crack repair material. For example, what is the blending amount C1 of the rust preventive agent in the first crack repair material, the blend amount C2 of the rust preventive agent in the second crack repair material, and the blend amount C3 of the rust preventive agent in the third crack repair material? , "C1>C2>C3" may be satisfied.

11 to 15 are perspective views illustrating the repair method according to the second embodiment.

(Cleaning process)
As shown in FIG. 11, a band-shaped area including cracks 20 on the surface (first main surface 10a) of the reinforced concrete structure 10 is cleaned.

(Sealing process)
As shown in FIG. 12, a temporary sealing material 21 is applied along the crack 20, leaving an injection point 22 in a band-shaped region including the crack 20. As shown in FIG.
As shown in FIG. 13, an injection device 23 for injecting the crack repair material is attached to the injection site 22.

(First injection step)
The first crack repair material 131 is obtained by mixing the base material and the curing agent.
As shown in FIG. 14, the first crack repair material 131 is injected into the crack 20 by the injection pump 30. Since the first crack repair material 131 has a low viscosity, it easily spreads throughout the crack 20.

(Second injection step)
A second crack repair material 132 is obtained by mixing the base material and the curing agent.
As shown in FIG. 15, the second crack repair material 132 is injected into the crack 20 by the injection pump 30. Since the second crack repair material 132 has a higher viscosity than the first crack repair material 131, even if an unfilled space remains in the crack 20 in the first injection step, it can fill this space. .

(Third injection step)
The third crack repair material 133 is obtained by mixing the base material and the curing agent.
As shown in FIG. 16, the third crack repair material 133 is injected into the crack 20 by the injection pump 30. Since the third crack repair material 133 has a higher viscosity than the second crack repair material 132, even if an unfilled space remains in the crack 20 in the second injection step, it can fill this space. .

After the crack repair materials 131 to 133 have hardened, the temporary sealing material 21 and the injection device 23 are removed.

In the crack repair method, a first crack repair material 131 is injected into the crack 20, then a second crack repair material 132 having a higher viscosity than the first crack repair material 131 is injected into the crack 20, and then, A third crack repair material 133 having a higher viscosity than the second crack repair material 132 is injected into the crack 20.

In the first injection step, since the first crack repair material 131 has a low viscosity, it penetrates into the narrow areas of the crack 20 and spreads throughout the crack 20 . The first crack repair material 131 spreads over a wide range on the surface of the internal reinforcing bars 12. Since the first crack repair material 131 has a high content of rust preventive agent, the rust preventive effect on the internal reinforcing bars 12 can be enhanced. Therefore, the durability of the reinforced concrete structure 10 can be improved.

In the second injection step, since the highly viscous second crack repair material 132 is used, even if an unfilled space remains in the crack 20 in the first injection step, this space can be filled. In the third injection step, the third crack repair material 133 with high viscosity is used, so even if an unfilled space remains in the crack 20 in the second injection step, this space can be filled. According to the second injection step and the third injection step, even if the intervals between the cracks 20 are large, the entire cracks 20 can be filled with the crack repair materials 131 to 133. Therefore, the durability of the repaired portion of the crack 20 can be increased.

In the crack repair method, the crack can be filled with the crack repair material without any gaps, so even if rust occurs in the internal reinforcing steel, it is possible to suppress water containing rust from leaking out of the crack. Therefore, it is possible to avoid staining the surface of the reinforced concrete structure with rust.

Although the crack repair material composition and crack repair method according to the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be freely modified within the scope of the present invention.
A structure with metal reinforcement that is a target of the crack repair method is not limited to a reinforced concrete (RC) structure, but may be a reinforced steel concrete (SRC) structure. In this case, reinforcing bars and steel frames are specific examples of metal reinforcement. The frame in which the metal reinforcing material is buried is not limited to concrete, and may be made of synthetic resin, ceramic, or the like. The metal constituting the metal reinforcing material is not particularly limited, and may include iron, copper, and alloys thereof, but is usually iron or an alloy thereof.

In the crack repair method of the second embodiment, three types of crack repair materials are used, but the number of crack repair materials may be two or any number greater than or equal to four.
When the number of crack repair materials is two, a first crack repair material is injected into the crack, and then a second crack repair material having a higher viscosity than the first crack repair material is injected into the crack.
When the number of crack repair materials is 4, a first crack repair material is injected into the crack, and then a second crack repair material having a higher viscosity than the first crack repair material is injected into the crack. A third crack repair material having a higher viscosity than the second crack repair material is then injected into the crack. Next, a fourth crack repair material having a higher viscosity than the third crack repair material is injected into the crack.

10...Reinforced concrete structure (structure with metal reinforcement), 20...Crack, 31...Crack repair material, 131...First crack repair material, 132...Second crack repair material, 133...Third crack repair material .

Claims (1)

A method for manufacturing a repaired structure, which manufactures a repaired structure by repairing cracks in a structure containing metal reinforcement, the method comprising:
preparing first and second crack repair material compositions containing an epoxy resin and a rust preventive agent and having different viscosities when prepared;
The repaired structure is obtained by injecting the first crack repair material composition into the cracks of the structure from the surface of the structure toward the back, and then injecting the second crack repair material composition. a step of manufacturing a body;
The first crack repair material composition has a lower viscosity than the second crack repair material composition,
The content rate of the rust preventive agent in the first crack repair material composition is higher than the content rate of the rust preventive agent in the second crack repair material composition,
The method for producing a repaired structure, wherein the rust inhibitor includes mineral oil, sorbitan fatty acid ester, and petroleum sulfonate.

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