JP5576580B1 - How to repair cracks in concrete structures - Google Patents

Abstract

[Problem] To propose a method capable of appropriately adjusting, for example, the permeability and sagging property of a processing agent in a construction site according to the temperature and the place of construction, and suitably repairing cracks and the like in a concrete structure.
SOLUTION: A liquid mainly composed of an epoxy resin, B liquid mainly composed of a curing agent, and C liquid mainly composed of modified urea are mixed at a mixing ratio of A liquid: B liquid: C liquid. By adjusting and mixing, the ratio (η5 / η50) between the viscosity at 5 rpm at 23 ° C. and the viscosity at 50 rpm at 23 ° C. measured with a B-type viscometer was 1.00 or more and less than 1.10. In addition, an osmotic repair composition having a viscosity of 100 to 1000 mPa · s at 23 ° C. is prepared, and the obtained osmotic repair composition is applied to the surface of a concrete structure to penetrate into fine cracks. We propose a method for repairing cracks in concrete structures, which is characterized by being cured.
[Selection figure] None

Description

  The present invention relates to a repair method when a fine crack or a fine crack enters a floor surface or a wall surface of a concrete structure.

  If the surface of the concrete structure has minute cracks or cracks due to aging after construction, leaving it as it is may cause water leakage, decrease concrete strength, or cause peeling. It causes various problems such as corroding internal rebars. Therefore, it is necessary to repair when cracks and cracks enter the surface of the concrete structure.

  As a repair method when a crack or a crack enters the surface of a concrete structure, for example, a repair method in which an adhesive is injected under pressure into a gap portion such as a crack generated in a concrete structure is known ( (See Patent Document 1 and Patent Document 2). At this time, as the adhesive, an epoxy resin two-component mixed adhesive having high adhesion to concrete and excellent in water resistance, alkali resistance, chemical resistance and the like is widely used.

  However, if the cracks and cracks are fine, it is difficult to inject the adhesive under pressure. Therefore, for example, in Patent Document 3, as a reinforcing method that allows the adhesive composition to penetrate and cure inside the fine cracks simply by applying to the concrete surface, A liquid mainly composed of an epoxy resin main component, A method using a two-pack type epoxy resin composition composed of a B liquid mainly composed of a curing agent has been proposed.

Japanese Patent Laid-Open No. 5-65768 JP 2000-121901 A JP 2002-121901 A

  As in the above-mentioned Patent Document 3, any cracking agent can be repaired if it is a treatment agent that can be penetrated into the interior of the microcrack and cured by simply applying it to the concrete surface. However, there are various environmental conditions at the construction site, for example, in winter when the temperature is low, the viscosity of the material tends to be high and the permeability tends to be poor, whereas in summer when the temperature is high, the viscosity of the material is low. Therefore, for example, when it is applied to the wall or ceiling of a building, sagging occurs, construction work becomes difficult, and the retention of the permeate inside the crack also deteriorates.

Also, if there are cracks from the floor surface to the wall surface of the concrete structure, the floor surface and the wall surface have different suitable permeability and sag, so different treatment agents with different compositions can be used depending on the construction environment and construction location. It is necessary to prepare each.
However, according to the construction environment and the construction place, if each treatment agent is prepared in advance, there is a problem that the treatment cost increases.

  Therefore, the present invention is a method capable of appropriately adjusting, for example, the permeability and sagging property of the treatment agent at the construction site according to the temperature and the place where the construction is performed, and suitably repairing cracks and the like in the concrete structure. Is a proposal.

  In the present invention, A liquid mainly composed of epoxy resin, B liquid mainly composed of a curing agent, and C liquid mainly composed of modified urea are mixed at a mixing ratio of A liquid: B liquid: C liquid. By adjusting and mixing, the ratio (η5 / η50) between the viscosity at 5 rpm at 23 ° C. and the viscosity at 50 rpm at 23 ° C. measured with a B-type viscometer was 1.00 or more and less than 1.10. In addition, an osmotic repair composition having a viscosity of 100 to 1000 mPa · s at 23 ° C. is prepared, and the obtained osmotic repair composition is applied to the surface of a concrete structure to penetrate into fine cracks. We propose a method for repairing cracks in concrete structures, which is characterized by being cured.

  In the crack repairing method for a concrete structure proposed by the present invention, the mixing ratio of the liquid A mainly composed of an epoxy resin, the liquid B mainly composed of a curing agent, and the liquid C mainly composed of a modified urea is obtained. By adjusting and mixing, the ratio (η5 / η50) of the viscosity at 5 rpm at 23 ° C. and the viscosity at 50 rpm at 23 ° C. and the viscosity at 23 ° C. are adjusted within a predetermined range to prepare an osmotic repair composition. Therefore, it is not necessary to prepare each osmotic repair composition according to the temperature, the construction place, etc. in advance, and the osmotic repair composition can be appropriately prepared and applied at the construction site. Therefore, even if the environment such as temperature changes or the construction site such as floor and wall changes, the permeability and sag can be adjusted accordingly at the construction site, and it is suitable for cracking in concrete structures Can be repaired.

  Next, the present invention will be described based on an embodiment. However, the present invention is not limited to the embodiment described below.

<Crack repair method>
According to an example of the present embodiment, a crack repair method (referred to as “the present repair method”) in a concrete structure is performed by preparing a predetermined osmotic repair composition at a construction site, and obtaining an osmotic repair composition ( A method for repairing a crack in a concrete structure, characterized in that the following “this permeation type repair composition” is applied to the surface of the concrete structure, and is penetrated into a fine crack and cured.

<Penetration type repair composition>
With respect to the present osmotic repair composition, a three-component osmotic repair comprising a liquid A mainly composed of an epoxy resin, a liquid B mainly composed of a curing agent, and a liquid C mainly composed of a modified urea. By adjusting and mixing the mixing ratio of A liquid: B liquid: C liquid, it is a composition, and the viscosity in 5 rpm at 23 degreeC and the viscosity in 50 rpm at 23 degreeC measured with a B-type viscometer In the range where the ratio (η5 / η50) is 1.00 or more and less than 1.10, it is preferable to adjust the viscosity appropriately.
In addition to the above three liquids, other components can be blended.

(Liquid A)
A liquid is a liquid which has an epoxy resin as a main component.

The epoxy resin is preferably a bisphenol type epoxy resin.
Here, as the bisphenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, novolac type epoxy resin (phenol novolac type epoxy resin, cresol novolac type epoxy resin), glycidylamine Based resins and the like. These can be used alone, or a resin in which two or more of these are combined and mixed can be used.
In addition, cycloaliphatic epoxy resins, glycidyl ester resins, heterocyclic epoxy resins, bromine-containing epoxy resins, and the like can be mixed and used as necessary.

  In addition to the epoxy resin, the liquid A can contain a reaction diluent such as glycidyl ether, a coupling agent such as a silane coupling agent, and other additives as necessary.

(Liquid B)
B liquid is a liquid which has a hardening | curing agent as a main component.
Here, as the curing agent, aliphatic primary amine (aliphatic diamine, aliphatic polyamine, aromatic ring-containing aliphatic polyamine, alicyclic polyamine, cyclic polyamine, etc.), aromatic primary amine, tertiary amine curing agent, Phosphorus- or halogen-containing amine curing agents, amine-based curing agents such as modified polyamine adducts, polyaminoamide-based curing agents, aliphatic acid anhydrides, alicyclic acid anhydrides, aromatic acid anhydrides, halogen acid anhydrides A curing agent such as an acid or acid anhydride curing agent can be used.
Among them, a modified aliphatic polyamine-based curing agent that provides a low potency and a long pot life, and a modified alicyclic amine-based curing agent that provides adhesion to a wet surface are preferable. Among them, a tertiary amine-based curing that provides low-temperature curability. An agent can be further blended.

  Liquid B can contain benzyl alcohol, a tertiary amine, and other additives as needed in addition to the curing agent.

(C liquid)
The liquid C is a liquid containing a modified urea as a main component and a solvent.
As the modified urea, various modified ureas such as acrylic-modified urea and epoxy-modified urea can be used.
As the solvent, xylene, alkylbenzene, isobutanol, methyl pyrrolidone, ethyl pyrrolidone, dimethyl sulfoxide, polypropylene glycol, monophenyl glycol, ethoxylate, and solvent naphtha, or a combination of two or more of these. Can be used.

(Mixing method)
As a mixing method of the A liquid, the B liquid, and the C liquid, the A liquid, the B liquid, and the C liquid may be mixed simultaneously, or the C liquid may be mixed with the mixed liquid of the A liquid and the B liquid. Alternatively, the liquid B may be mixed with the liquid mixture of the liquid A and the liquid C, or the liquid A may be mixed with the liquid mixture of the liquid B and the liquid C. It may be. Especially, it is preferable to mix C liquid with respect to the liquid mixture of A liquid and B liquid.

(Adjustment of mixing ratio)
About this osmotic type repair composition, it adjusts the mixing ratio of A liquid: B liquid: C liquid according to temperature and the place to construct, and mixes it at 23 degreeC measured with a B type viscometer. The ratio of the viscosity at 5 rpm to the viscosity at 50 rpm at 23 ° C. (η 5 / η 50) is 1.00 or more and less than 1.10, and the viscosity at 23 ° C. is 100 to 1000 mPa · s, particularly 300 or more and 900 or less. Of these, it is preferable to prepare the present osmotic repair composition so that it is 500 or more or 800 or less.

  Specifically, for example, when repairing a floor surface in an environment at an air temperature of 5 to 25 ° C., by adjusting and mixing the mixing ratio of A liquid: B liquid: C liquid, The ratio (η5 / η50) of the viscosity at 5 rpm at 23 ° C. and the viscosity at 50 rpm at 23 ° C. is 1.00 to 1.05, and the viscosity at 23 ° C. is 500 to 900 mPa · s, In particular, it is preferable to prepare an osmotic repair composition that is 600 mPa · s or more.

  Further, for example, when repairing a wall surface in an environment with an air temperature of 5 to 25 ° C., it is measured with a B-type viscometer by adjusting and mixing the mixing ratio of A liquid: B liquid: C liquid 23 The ratio (η5 / η50) of the viscosity at 5 rpm at 23 ° C. to the viscosity at 50 rpm at 23 ° C. is 1.05 or more and less than 1.10, and the viscosity at 23 ° C. is 300 to 700 mPa · s, especially 600 mPa · s. It is preferable to prepare this penetration type repair composition which is s or less.

<Construction method>
Concrete structures that can be repaired using this repair method include, for example, concrete floor boards, concrete bridge piers, concrete beams, concrete outer walls, concrete building walls / floors / ceilings, concrete mounts, concrete dams, concrete sabo dams. , Tunnels, buildings, and the like. Of these, floors, walls, and ceilings of concrete buildings are particularly suitable. However, it is not limited to those illustrated.

The cracks, cracks and cracks repaired by this repair method (in the present invention, these are collectively referred to as “cracks”) can enjoy the effect of this repair method when they are finer.
Specifically, cracks such as fine cracks (including hair cracks and shrinkage cracks) having a groove width of less than 0.5 mm are particularly suitable for applying this repair method.

What is necessary is just to repeat the operation | movement which apply | coats this penetration type repair composition prepared as mentioned above to the surface of the cracked concrete structure with a roller, a brush, etc. once or the required number of times.
After application, the penetration type repair composition can naturally permeate and fill cracks in the concrete structure. The infiltrated main permeation type repair composition, for example, at 23 ° C., is naturally cured in about 12 hours, and can repair cracks in the concrete structure.

<Explanation of words>
In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X is preferably greater than X” or “preferably Y”. It also includes the meaning of “smaller”.
In addition, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), it is “preferably greater than X” or “preferably less than Y”. Includes intentions.

  Hereinafter, the present invention will be further described in detail based on the following examples and comparative examples.

<Liquid A>
As A liquid, what mixed 28.6 g of glycidyl ethers and 0.7 g of silane coupling agents in 100 g of liquid bisphenol A type epoxy resins was prepared.

<Liquid B>
As B liquid, what mixed 15 g of benzyl alcohol and 10 g of tertiary amines in 100 g of modified aliphatic polyamines as curing agents was prepared.

<C liquid>
As liquid C, 10 g of modified urea and 40 g of benzyl alcohol were prepared.

<Examples and comparative examples>
A 40 mm × 40 mm × 80 mm mortar was divided into two mortar pieces, and a 0.2 mm aluminum foil was sandwiched between the two mortar pieces to prepare a specimen having a crack having a width of about 0.2 mm.
A mixture of 70 parts by mass of the above-mentioned A liquid and 30 parts by mass of B liquid is mixed with the amount of C liquid shown in Tables 1 and 2 to adjust the 23 ° C. viscosity and the 23 ° C. fluctuation value. An osmotic repair composition was prepared.
And each penetration type repair composition was apply | coated to the floor surface or the wall surface 3 times with the brush in the environment of 5 degreeC or 23 degreeC, and the ease of application | coating, the sagging degree, and the penetration depth were observed.

The ease of application was evaluated as “Δ” when it was difficult to apply with a brush, “◯” when it could be applied without difficulty with a brush, and “◎” when it could be easily applied with a brush.
As for the sagging property, “△” indicates that sagging is clearly seen in the applied material, “◯” indicates that sagging is slightly seen in the applied material, and “sag” is not seen in the applied material. Evaluated as “◎”.
About the penetration depth, the state 30 minutes after material application was measured as penetration depth. For the floor surface, the penetration depth of less than 30 mm is evaluated as “Δ”, 30 mm or more and less than 40 mm is evaluated as “◯”, and 40 mm or more is evaluated as “◎”. 15 mm or more and less than 25 mm were evaluated as “◯”, and 25 mm or more were evaluated as “◎”.

<Measurement of viscosity and fluctuation value>
The viscosity (mPa · s) at 23 ° C. was measured with a B-type viscometer.
Further, the ratio (23 ° C. fluctuation value, η 5 / η 50) of the viscosity at 5 rpm and the viscosity at 50 rpm at 23 ° C. measured with a B-type viscometer was measured.

(Results and discussion)
From the results of the above examples and the test results conducted by the inventors so far, liquid A containing epoxy resin as the main component, liquid B containing the curing agent as the main component, and liquid C containing the modified urea as the main component. By adjusting the mixing ratio and mixing, the ratio of the viscosity at 5 rpm at 23 ° C. and the viscosity at 50 rpm at 23 ° C. measured with a B-type viscometer (depending on the temperature and construction location, especially the construction location ( η5 / η50) is 1.00 or more and less than 1.10 and has a 23 ° C. viscosity of 100 to 1000 mPa · s to prepare an osmotic repair composition at a construction site. It was found that can be appropriately prepared and applied.

Claims (3)

Mixing A liquid mainly composed of epoxy resin, B liquid mainly composed of curing agent, and C liquid mainly composed of modified urea by adjusting the mixing ratio of A liquid: B liquid: C liquid Thus, the ratio (η5 / η50) of the viscosity at 5 rpm at 23 ° C. and the viscosity at 50 rpm at 23 ° C. measured by a B-type viscometer is 1.00 or more and less than 1.10, and Preparing an osmotic repair composition having a viscosity of 100 to 1000 mPa · s at 23 ° C .;
A method for repairing a crack in a concrete structure, characterized in that the obtained penetration-type repair composition is applied to the surface of a concrete structure, and is penetrated into a fine crack and cured.   When repairing the floor surface in an environment where the temperature is 5 to 25 ° C., the mixture is adjusted at a mixing ratio of A liquid: B liquid: C liquid and mixed at 23 ° C. measured by a B-type viscometer. Penetration type repair composition whose ratio (η5 / η50) of the viscosity at 5 rpm to the viscosity at 50 rpm at 23 ° C. is 1.00 or more and 1.05 or less and the viscosity at 23 ° C. is 500 to 900 mPa · s. The method for repairing cracks in a concrete structure according to claim 1, wherein: When repairing the wall surface in an environment where the temperature is 5 to 25 ° C., 5 rpm at 23 ° C. measured with a B-type viscometer by adjusting the mixing ratio of A liquid: B liquid: C liquid and mixing. A penetration type repair composition in which the ratio (η5 / η50) of the viscosity at 50 ° C. at 23 ° C. to 1.05 or more and less than 1.10 and the 23 ° C. viscosity is 300 to 700 mPa · s. The method for repairing a crack in a concrete structure according to claim 1, wherein the crack is repaired.