WO2023008097A1

WO2023008097A1 - Structure protection sheet, and method for manufacturing reinforced structure

Info

Publication number: WO2023008097A1
Application number: PCT/JP2022/026445
Authority: WO
Inventors: 有希松野
Original assignee: 恵和株式会社
Priority date: 2021-07-28
Filing date: 2022-07-01
Publication date: 2023-02-02
Also published as: JP2023018895A; TW202309384A

Abstract

Provided is a structure protection sheet that has exceptional strength and that makes it possible to greatly reduce the construction time when a protective layer is provided to the surface of a structure made of concrete, etc., and to protect the structure over an extended period of time. This structure protection sheet comprises a polymer cement hardened layer, which is provided on the structure side, and a resin layer, which is provided on the polymer cement hardened layer. The structure protection is characterized in that when the sheet is irradiated with light emitted by a xenon lamp for 72 hours, the light having a radiation intensity of 180 W/m 2, the rate of change in the moisture permeability between before and after the irradiation is not more than 35%.

Description

Structural protection sheet and method for manufacturing reinforced structure

The present invention relates to a structure protection sheet and a method for manufacturing a reinforced structure. More specifically, a structure protection sheet that can greatly reduce the construction period for providing a protective layer on the surface of a structure such as concrete and protect the structure for a long period of time, and reinforcement using the structure protection sheet The present invention relates to a method for manufacturing a constructed structure.

As road bridges, tunnels, water gates and other river management facilities, sewer pipes, and bay quay walls deteriorate, repair and reinforcement work will be carried out. Repair work is carried out by recoating the coating material several times after repairing the defective or weak parts. On the other hand, the reinforcement work is carried out by coating the entire portion to be reinforced with a reinforcing coating material multiple times.

Overcoating in such repair work and reinforcement work, for example, is performed on concrete in the order of undercoating, intermediate coating, and topcoating. For example, when applying a total of 5 layers of undercoat, 1st intermediate coat, 2nd intermediate coat, 1st topcoat, and 2nd topcoat, it takes at least 5 days. Moreover, since the painting is done outdoors, it is affected by the weather. Therefore, it is difficult to shorten the construction period, labor costs are high, and the quality of the construction and coating film (film thickness, surface roughness, moisture content, etc.) depends on the external environment (humidity, temperature, etc.) during the coating process. As a result of being affected, it is difficult to become stable.

In addition, painting is done by troweling or spraying, but stable repairs and reinforcements with uniform coating largely depend on the skill of the craftsman. Therefore, the quality of the coating film varies depending on the skill of the craftsmen. Furthermore, with the aging of construction workers and the declining population, the number of workers engaged in concrete repair and reinforcement work is decreasing. ing.

As a technique for solving these problems, Patent Document 1, for example, proposes a sheet and method that is simple, inexpensive, shortens the construction period, and reliably prevents deterioration of concrete. In this technique, a concrete repair sheet comprising an intermediate layer having a resin film and surface layers made of a fabric material laminated on both sides with an adhesive resin is attached to the concrete surface to be repaired with a construction adhesive. and then coating the surface layer of the pasted sheet for repairing concrete on the side opposite to the concrete surface with a coating material.

Improvements have also been made to coating materials. For example, in Patent Document 2, it prevents alkali-aggregate reaction, has excellent conformability to cracks in concrete structures, does not cause blistering of the coating film even when the temperature rises after the coating film is formed, A method for protecting a concrete structure using a coating material capable of preventing concrete from spalling has been proposed. This technique is a method of forming a substrate conditioning material coating film on the surface of a concrete structure and then forming a coating film on the coating film surface. The base conditioning material coating film is formed from a composition containing a cationic (meth)acrylic polymer emulsion and an inorganic hydraulic substance. The coating film formed on the surface of the base conditioning material coating film is a coating film formed from a composition containing an alkyl (meth)acrylate emulsion and an inorganic hydraulic substance, and has an elongation rate of 50 to 2000% at 20°C. , the salt barrier property is 10 ⁻² to 10 ⁻⁴ mg/cm ² ·day, the water vapor permeability is 5 g/m·day or more, and the film thickness is 100 to 5000 μm.

JP 2010-144360 A JP-A-2000-16886

Conventional concrete repair sheets such as those disclosed in Patent Document 1 have differences in adhesive strength between the substrate and other layers (e.g., adhesive layer and reinforcing member), differences in elongation of the substrate, adhesive layer, reinforcing member, etc., and adhesion There are problems to be solved, such as the problem of adhesive strength between the agent layer and concrete. Specifically, the base material and the reinforcing member are bonded together with an adhesive layer. Differences in the elongation of members and the like can cause peeling at the layer interface based on the difference in the adhesive strength between the substrate and the adhesive layer and the adhesive strength between the adhesive layer and the reinforcing member.

In addition, the adhesive layer provided on the concrete repair sheet is softened by heating or the like and is bonded to the concrete. It may not work. In addition, after the concrete repair sheet was applied, the concrete sometimes swelled over time. This phenomenon was caused by the presence of the repair sheet, which has low water vapor permeability, and prevented the water vapor inside the concrete from escaping. It is considered to be

In addition, the method of forming a coating film by coating on site, as described in the background art section above, takes one day for each coating layer, and from the undercoat to the topcoat layer, for example, a six-layer coating film. It takes as long as 6 days to form , and there are problems that the film thickness varies and the quality and characteristics such as surface roughness and water content are difficult to stabilize.

Furthermore, since the repair target of the concrete repair sheet is usually large concrete members such as road bridges, tunnels, river management facilities such as water gates, sewage pipes, and civil engineering structures such as quay walls, the concrete repair sheet itself is sufficient. strength (tensile strength, bending strength, hardness, surface strength, punching strength, toughness, etc.; the same applies hereinafter) is required, but conventional concrete repair sheets are considered to have sufficient strength. is difficult to say.

The present invention has been made to solve the above problems, and its object is to significantly reduce the construction period when providing a protective layer on the surface of a structure such as concrete, and to protect the structure over a long period of time. It is an object of the present invention to provide a structure protection sheet capable of restructuring and a method for manufacturing a reinforced structure using the structure protection sheet.

The present inventors have researched a concrete protective sheet that can stably protect concrete for a long period of time without depending on the construction method of forming a layer on the surface of concrete by coating means. As a result, it was found that the concrete protection sheet should be given performance according to the characteristics of the concrete. A structure protection sheet having a polymer cement hardened layer and a resin layer, further equipped with waterproof, salt-blocking, neutralization prevention, and water vapor permeability that allows the water in concrete to be discharged as water vapor. was completed first.
However, in the structure protection sheet that the present inventors completed earlier, the polymer cement hardened layer deteriorates due to exposure to sunlight, and there is a possibility that the performance imparted according to the characteristics of concrete will decrease. was there.
As a result of further intensive studies, the inventors realized that the rate of change in moisture permeability of the structure protection sheet before and after exposure to sunlight was within a specific range, and completed the present invention. This technical idea can also be applied as a structure protection sheet to structures other than those for concrete.

(1) A structure protection sheet according to the present invention is a structure protection sheet comprising a polymer cement hardened layer provided on the structure side and a resin layer provided on the polymer cement hardened layer. The change rate of moisture permeability before and after irradiation with light from a xenon lamp of 180 W/m ² for 72 hours is 35% or less.

According to the present invention, the polymer cement-hardened layer can suitably prevent the performance imparted from deteriorating even when exposed to sunlight.
In addition, since the structure protection sheet can be mass-produced by coating and drying processes on the factory production line, it is possible to reduce costs, significantly reduce the work period on site, and achieve long-term protection of structures.

In the structure protection sheet according to the present invention, it is preferable that the polymer cement hardening layer is subjected to water absorption treatment.

According to this invention, it is possible to suitably prevent deterioration of the performance imparted to the polymer cement hardened layer when exposed to sunlight.

In the structure protection sheet according to the present invention, the water absorption treatment includes a method of adding a water absorbing polymer to the polymer cement hardening layer, a method of adding an inorganic water absorbing substance to the polymer cement hardening layer, and a method of adding an inorganic water absorbing substance to the polymer cement hardening layer. A method of performing aging treatment in a high humidity environment when producing, a method of performing heat treatment in a high humidity environment when forming the resin layer, and providing a water-containing sheet in which water is absorbed in the polymer cement hardened layer It is preferably any method selected from the group consisting of a method and a method of performing wet curing after applying the structure protection sheet.

According to this invention, the water absorption treatment of the hardened layer of polymer cement can be suitably realized.

In the structure protection sheet according to the present invention, the polymer cement-hardening layer is a layer containing a cement component and a resin, and may contain 10% by weight or more and 40% by weight or less of the resin. More preferably, the resin content is 20% by weight or more and 30% by weight or less.

According to the present invention, by controlling the ratio of the cement component and the resin component, it becomes easier to form the polymer cement hardened layer, and the polymer cement hardened layer tends to be a layer with excellent conformability and good compatibility. It tends to improve the adhesiveness of itself. Furthermore, the cement component contained in the polymer-cement-hardened layer on the structure side acts to enhance adhesion to structures such as concrete.

(2) The present invention is a method for manufacturing a structure using the structure protection sheet according to the present invention, characterized in that the structure protection sheet is laminated after applying an adhesive onto the structure. and

According to the present invention, a structure protection sheet that is composed only of layers that do not contain a base material or a reinforcing member is used, so that it can be easily attached to the surface of the structure. As a result, even an unskilled worker can stably apply a structure protection sheet with excellent strength to the surface of a structure, significantly reducing the construction period and protecting the structure over a long period of time. can.

In the method for manufacturing a reinforced structure according to the present invention, an undercoat layer may be provided between the structure and the adhesive.

According to this invention, the undercoat layer provided between the structure and the adhesive acts to enhance mutual adhesion, so that the structure protection sheet can stably protect the structure for a long period of time. .

According to the present invention, even when it is attached to the surface of a structure such as concrete and exposed to sunlight, the rate of change in moisture permeability is within a predetermined range, so that the performance imparted is not degraded. It is possible to provide a structure protection sheet capable of suitably preventing damage and protecting the surface of a structure over a long period of time, and a method for manufacturing a reinforced structure using the structure protection sheet. In particular, the structure protection sheet is given performance according to the characteristics of the structure, so that it can follow the cracks and expansion that occur in the structure, and it prevents deterioration factors such as water and chloride ions from penetrating into the structure. In addition, it is possible to provide a structure protection sheet that realizes permeability that enables the discharge of water and deterioration factors in the structure, and that the strength is improved. Furthermore, it has the advantage of being able to improve the stability and uniformity of quality compared to layers that have been formed by hand coating.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional block diagram which shows an example of the structure protection sheet which concerns on this invention. It is explanatory drawing of the construction method of a structure protection sheet. It is explanatory drawing which shows the example which applied the structure protection sheet to the cast-in-place construction method. 4 is a graph showing the results of the rate of change in water vapor permeability according to Examples and Comparative Examples.

Hereinafter, a structure protection sheet according to the present invention and a reinforced concrete structure using the same will be described with reference to the drawings. The present invention can be modified in various ways as long as it has the technical features, and is not limited to the following description and drawings.

[Structure protection sheet]
As shown in FIG. 1 or FIG. 2C, the structure protection sheet 1 according to the present invention comprises a hardened polymer cement layer 3 provided on the side of a structure 21, and a hardened polymer cement layer 3 provided on the hardened polymer cement layer 3. layer 2; Both the polymer cement hardened layer 3 and the resin layer 2 may be formed as a single layer or as a laminate. Another layer may be provided between the hardened polymer cement layer 3 and the resin layer 2 depending on the required performance.

The structural protection sheet 1 according to the present invention has a rate of change in moisture permeability of 35% or less before and after being irradiated with light from a xenon lamp with a radiation intensity of 180 W/m ² for 72 hours. The rate of change in moisture permeability is calculated by {(N2−N1)/N2}×100 where N1: moisture permeability before xenon lamp irradiation and N2: moisture permeability after xenon lamp irradiation.
If the rate of change in moisture permeability exceeds 35%, when the structure protection sheet 1 according to the present invention is attached to the surface of a structure, the resulting performance is degraded due to exposure to sunlight. There is A preferred lower limit of the rate of change in moisture permeability is 0%, and a preferred upper limit is 20%.
The moisture permeability is a value measured according to JIS Z0208:1976.

The reason why deterioration of the imparting performance of the structure protection sheet 1 according to the present invention can be prevented by specifying such a rate of change in moisture permeability is as follows.
The hardened polymer cement layer 3 is a layer containing a cement component and a resin component as will be described later. Continue to change to a stronger layer.
When such a structure protection sheet 1 according to the present invention is attached to the surface of a structure 21, in the conventional structure protection sheet, the moisture content in the polymer cement hardened layer 3 changes due to sunlight irradiation ( In addition, there is a problem that the hardening reaction of the hardened polymer cement layer 3 changes with the passage of time, resulting in insufficient hardening.
Therefore, in the structure protection sheet 1 according to the present invention, irradiation with a xenon lamp that simulates sunlight irradiation is performed under predetermined conditions to limit the upper limit of the rate of change in moisture permeability.

In order to satisfy such a rate of change in moisture permeability, for example, in the structure protection sheet 1 according to the present invention, the polymer cement hardened layer 3 is preferably subjected to water absorption treatment.
The water absorption treatment is a treatment that allows the hardened polymer cement layer 3 to retain moisture. It becomes possible to satisfy the rate of change.

Examples of the water absorption treatment include a method of adding a water absorbing polymer to the polymer cement hardened layer 3, a method of adding an inorganic water absorbing substance to the polymer cement hardened layer 3, and an aging treatment when producing the polymer cement hardened layer 3. in a high-humidity environment, a method in which the heat treatment for forming the resin layer 2 is performed in a high-humidity environment, a method in which a water-containing sheet is provided in which the hardened polymer cement layer 3 absorbs water, and the structure protection sheet 1 is Any method selected from the group consisting of wet curing after construction is preferably used.

In the method of adding a water-absorbing polymer to the polymer cement hardened layer 3, examples of the water-absorbing polymer include Aqualic CA (manufactured by Nippon Shokubai Co., Ltd.).
The content of the water-absorbent polymer is preferably 0.15 to 0.30 parts by mass with respect to 100 parts by mass of the resin component in the hardened polymer cement layer 3, for example. If it is less than 0.15 parts by mass, the rate of change in moisture permeability of the structure protection sheet 1 according to the present invention may increase, and if it exceeds 0.30% by mass, the viscosity increases and coating becomes impossible. Sometimes.

In the method of performing the aging treatment in a high-humidity environment when producing the polymer cement hardened layer 3, the high-humidity environment is preferably an environment with a humidity of 50% RH or less.
Further, as the aging treatment, specifically, there is a treatment of leaving the hardened polymer cement layer 3 in the high humidity environment for 24 to 72 hours.

In the method of performing the heat treatment for forming the resin layer 2 in a high-humidity environment, the high-humidity environment includes the environment described above, and the temperature of the heat treatment constitutes the resin layer 2 used. Although it is appropriately determined according to the resin material to be used, etc., it is preferably 60 to 80° C., for example.

In the method of providing a water-containing sheet in which water is absorbed in the hardened layer 3 of polymer cement, examples of the water-containing sheet include a non-woven fabric and the like which has been impregnated with water.
Further, the water-containing sheet may be in a state of being embedded inside the polymer cement hardened layer 3, and may be on the surface of the polymer cement hardened layer 3 on the resin layer 2 side or on the resin layer 2 of the polymer cement hardened layer 3. may be provided on the opposite side of the side.

As a method for performing wet curing after applying the structure protection sheet 1, the same methods as those conventionally performed for accelerating the hardening of cement can be mentioned. Wrapping is preferred.

The structure protection sheet 1 according to the present invention preferably has a thickness distribution within ±100 μm. Since the structure protection sheet 1 has a thickness distribution within the above range, even an unskilled worker can stably form a layer with small thickness variations on the surface of the structure 21 . Further, by controlling the thickness distribution within the above range, it becomes easier to uniformly reinforce the structure.
The hardened polymer cement layer 3 provided on the side of the structure 21 has excellent adhesion to the structure 21, and since it has a known primer layer 5, the step of applying and drying an adhesive is unnecessary. becomes. Moreover, the resin layer 2 provided on the polymer cement hardened layer 3 can impart properties such as waterproofness, salt barrier properties, and neutralization prevention properties.
In addition, since the structure protection sheet 1 can be mass-produced by the coating process and the drying process on the production line of the factory, it is possible to reduce the cost, significantly reduce the work period at the site, and achieve long-term protection of the structure. As a result, it is possible to greatly reduce the time required for attaching the film to the surface of the structure 21 and to protect the structure 21 for a long period of time.

Specific examples of each component are described in detail below.

(Structure)
The structure 21 is a mating member to which the structure protection sheet 1 according to the present invention is applied.
As the structure 21, a structure made of concrete can be mentioned.
The concrete is generally obtained by placing and curing a cement composition containing at least a cementitious inorganic substance, an aggregate, an admixture and water. Such concrete is widely used as civil engineering structures such as road bridges, tunnels, water gates and other river management facilities, sewer pipes, harbor quays and the like. In the present invention, by applying the structure protection sheet 1 to the structure 21 made of concrete, it is possible to follow the cracks and expansion that occur in the concrete, and prevent deterioration factors such as water and chloride ions from penetrating into the concrete. There is a particular advantage that water in concrete can be discharged as steam.

(polymer cement hardening layer)
The polymer cement hardening layer 3 is a layer arranged on the structure side, as shown in FIG. 2(C). This polymer cement hardening layer 3 may be a single layer or a laminate. ), can be arbitrarily set in consideration of the production line of the factory, production cost, etc. For example, if the production line is short and a single layer does not have a predetermined thickness, two or more layers can be overcoated. For example, when two layers are overcoated, the second layer is formed after drying the first layer.
The hardened polymer cement layer 3 may also have a structure in which layers having different properties are laminated. For example, by forming a layer with a higher resin component ratio on the resin layer 2 side, the layer with a higher resin component will adhere to the resin layer 2, and the layer with a higher cement component will adhere to the concrete structure 21. Adhesiveness to is extremely excellent.

The hardened polymer cement layer 3 is obtained by applying a coating made of resin containing a cement component (resin component). When a method of adding a water-absorbing polymer or an inorganic water-absorbing substance to the hardened polymer cement layer 3 is employed as the water-absorbing treatment, the water-absorbing polymer or inorganic water-absorbing substance is added to the paint.
Examples of the cement component include various cements, limestones containing calcium oxide components, and clays containing silicon dioxide. Among them, cement is preferable, and examples thereof include portland cement, alumina cement, high-early strength cement, fly ash cement, and the like. Which cement is selected is selected according to the properties that the hardened polymer cement layer 3 should have, for example, the degree of conformability to the concrete structure 21 is considered. Portland cement defined in JIS R5210 is particularly preferred.

Examples of the resin component include acrylic resin, acrylic urethane resin, acrylic silicone resin, fluororesin, flexible epoxy resin, polybutadiene rubber, acrylic resin exhibiting rubber properties (e.g., synthetic rubber containing acrylic acid ester as a main component), etc. can be mentioned. Such a resin component is preferably the same as the resin component constituting the resin layer 2 described later, from the viewpoint of enhancing the adhesion between the polymer cement hardened layer 3 and the resin layer 2 .
Moreover, any of a thermoplastic resin, a thermosetting resin, and a photocurable resin may be used as the resin component. The term "cured" in the polymer cement cured layer 3 does not mean that the resin component is limited to a resin that cures and polymerizes, such as a thermosetting resin or a photocurable resin. It is used in the sense that it is sufficient to use a material that hardens to a certain degree.

The content of the resin component is adjusted appropriately according to the material used, etc., but is preferably 10% by weight or more and 40% by weight or less with respect to the total amount of the cement component and the resin component. If it is less than 10% by weight, the adhesion to the resin layer 2 tends to decrease and it becomes difficult to maintain the polymer cement hardening layer 3 as a layer. Adhesion may be insufficient. From the above viewpoint, the content of the resin component is more preferably 15% by weight or more and 35% by weight or less, and more preferably 20% by weight or more and 30% by weight or less.

The paint for forming the hardened polymer cement layer 3 is a coating liquid obtained by mixing a cement component and a resin component with a solvent. The resin component is preferably an emulsion. For example, an acrylic emulsion is polymer fine particles obtained by emulsion polymerization of a monomer such as an acrylic ester using an emulsifier. An acrylic polymer emulsion obtained by polymerizing a mixture in water containing a surfactant is preferably used.
The content of the acrylic acid ester and the like constituting the acrylic emulsion is not particularly limited, but is selected within the range of 20 to 100% by weight. Further, the amount of the surfactant is also blended according to need, and the amount is not particularly limited, but the surfactant is blended to the extent that it forms an emulsion.

The hardened polymer cement layer 3 is formed by applying the coating solution onto a release sheet and then removing the solvent (preferably water) by drying. For example, a mixed composition of a cement component and an acrylic emulsion is used as a coating liquid to form the hardened polymer cement layer 3 . Although the resin layer 2 may be formed on the release sheet after forming the polymer cement hardened layer 3, the polymer cement hardened layer 3 is formed after the resin layer 2 is formed on the release sheet. may
Specifically, for example, a process paper as a release sheet is coated with a resin layer, and after drying, a coating liquid for polymer cement is applied, and a Young's modulus adjusting layer is attached in a wet state before drying. dry.
After that, a coating liquid for polymer cement is further applied to the surface to which the Young's modulus adjusting layer is attached, and dried to obtain a structure protection sheet in which the Young's modulus adjusting layer is present in the polymer cement hardened layer according to the present invention. Obtainable.
In addition, a step of coating a resin layer on a process paper as a release sheet, applying a coating liquid for polymer cement after drying, laminating a Young's modulus adjusting layer in a wet state before drying, and then drying. The Young's modulus adjusting layer is present in the hardened layer of the polymer cement according to the present invention by further coating the surface to which the Young's modulus adjusting layer is attached without drying, and then drying the entire surface. It is also possible to obtain a structure protection sheet.

The thickness of the hardened polymer cement layer 3 is not particularly limited, and the type of use of the structure 21 (road bridges, tunnels, river facilities such as water gates, civil engineering structures such as sewer pipes, harbor quays, etc.), age, and shape. etc. is arbitrarily set. Specifically, the thickness of the hardened polymer cement layer 3 can be, for example, in the range of 0.5 mm to 1.5 mm. As an example, when the thickness is 1 mm, the thickness variation is preferably within ±100 μm. Such a precise thickness cannot be achieved by on-site coating, but can be achieved by stably coating on a factory production line. Even if the thickness is greater than 1 mm, the thickness variation can be kept within ±100 μm. Moreover, when the thickness is less than 1 mm, the thickness variation can be further reduced.

Due to the presence of the cement component, this hardened polymer cement layer 3 is more easily permeable to water vapor than the resin layer 2 which will be described later. The water vapor transmission rate at this time is, for example, about 20 to 60 g/m ² ·day. Furthermore, the cement component has good compatibility with, for example, the cement component that constitutes concrete, and can be made to have excellent adhesion to the concrete surface. Also, as shown in FIG. 2, when the undercoat layer 22 and the adhesive 23 are provided in order on the surface of the structure 21, the polymer cement hardened layer 3 containing the cement component adheres well to the adhesive 23. Glue. In addition, since the hardened polymer cement layer 3 has extensibility, it can follow changes in the concrete even if the structure 21 cracks or expands.

(resin layer)
The resin layer 2 is a layer arranged on the side opposite to the structure 21 and appearing on the surface, as shown in FIG. 2(C). The resin layer 2 may be, for example, a single layer as shown in FIG. 1(A), or may be a laminate consisting of at least two layers as shown in FIG. 1(B). Whether to use a single layer or multiple layers takes into account the overall thickness, the functions to be imparted (waterproofness, salt barrier, neutralization prevention, water vapor permeability, etc.), the length of the factory production line, the production cost, etc. For example, if the production line is short and a single layer does not have a predetermined thickness, two or more layers can be overcoated. In the case of overcoating, the second layer is applied after drying the first layer. The second layer is then dried.

The resin layer 2 is coated with a paint that has flexibility, can follow cracks and cracks that occur in concrete, and can form a resin layer that is excellent in waterproofness, salt shielding, neutralization prevention, and water vapor permeability. obtained by Examples of the resin constituting the resin layer 2 include acrylic resins exhibiting rubber characteristics (for example, synthetic rubber containing acrylic acid ester as a main component), acrylic urethane resins, acrylic silicone resins, fluorine resins, flexible epoxy resins, polybutadiene rubbers, and the like. can be mentioned. This resin material is preferably the same as the resin component constituting the polymer cement layer 2 described above. In particular, it is preferably a resin containing an elastic film-forming component such as rubber.

　Among these, acrylic resins exhibiting rubber properties are preferably composed of aqueous emulsions of acrylic rubber copolymers in terms of excellent safety and coatability. Incidentally, the proportion of the acrylic rubber copolymer in the emulsion is, for example, 30 to 70% by weight. An acrylic rubber copolymer emulsion is obtained, for example, by emulsion polymerization of monomers in the presence of a surfactant. Any of anionic, nonionic and cationic surfactants can be used.

The paint for forming the resin layer 2 is prepared by preparing a mixed coating liquid of a resin composition and a solvent, applying the coating liquid on a release sheet, and then removing the solvent by drying. Form layer 2; The solvent may be water, an aqueous solvent, or an organic solvent such as xylene/mineral spirit. In Examples described later, a water-based solvent is used, and the resin layer 2 is made of an acrylic rubber composition. The order of the layers formed on the release sheet is not limited. may be in that order. However, it is preferable to form the resin layer 2 on the release sheet and then form the hardened polymer cement layer 3, as shown in Examples described later.

The thickness of the resin layer 2 is arbitrarily set according to the type of use of the structure 21 (road bridge, tunnel, river management facility such as a water gate, civil engineering structure such as a sewage pipe, port quay, etc.), degree of aging, shape, and the like. be. As an example, it is preferable that the thickness be within the range of 50 to 150 μm, and that the thickness variation be within ±50 μm. Thickness with such precision cannot be achieved by coating on site, and can be stably achieved on the production line of the factory.

This resin layer 2 has high waterproof properties, salt-shielding properties, and neutralization-preventing properties, but is preferably permeable to water vapor. At this time, the water vapor transmission rate is preferably about 10 to 50 g/m ² ·day, for example. By doing so, the structure protection sheet 1 can be endowed with high waterproof properties, salt barrier properties, neutralization prevention properties, and predetermined water vapor permeability. Further, by being composed of the same kind of resin component as the polymer cement hardening layer 3, the compatibility with the polymer cement hardening layer 3 is good and the adhesion can be excellent. The water vapor permeability was measured according to JIS Z0208 "Test method for moisture permeability of moisture-proof packaging materials".

Moreover, the resin layer 2 may contain a pigment from the viewpoint of increasing the color variations of the structure protection sheet 1 according to the present invention.
Moreover, the resin layer 2 may contain an inorganic substance. By containing an inorganic substance, the resin layer 2 can be imparted with scratch resistance. The inorganic material is not particularly limited, and examples thereof include conventionally known materials such as metal oxide particles such as silica, alumina, and titania.
Furthermore, the resin layer 2 may contain a known antifouling agent. Since the structure protection sheet according to the present invention is usually used for repairing concrete structures installed outdoors, the resin layer 2 is often contaminated. It is possible to suitably prevent the structure protection sheet from being contaminated. The antifouling agent is not particularly limited and includes conventionally known materials.
Moreover, the resin layer 2 may contain additives capable of imparting various functions. Examples of such additives include cellulose nanofibers and the like.

(Other configurations)
The manufactured structure protection sheet 1 may have a release sheet on one side of the polymer cement hardening layer 3 and the resin layer 2 . For example, the release sheet can protect the surface of the structure protection sheet 1 when it is sent to the construction site, and at the construction site, it is applied on the target structure 21 (or via the undercoat layer 22 or the adhesive 23). 3) Adhering the structure protection sheet 1 to which the release sheet is attached and then easily peeling off the release sheet greatly improves workability at the construction site. The release sheet is preferably process paper used in the production process of the structure protection sheet 1 .

The material of the process paper used as the release sheet is not particularly limited as long as it is conventionally known and used in the manufacturing process. For example, laminated paper having an olefin resin layer such as polypropylene or polyethylene or a silicon-containing layer, like known process paper, can be preferably used. The thickness is not particularly limited, but it can be any thickness, for example, about 50 to 500 μm, as long as the thickness does not impede handling in terms of manufacturing and construction.

In the structure protection sheet 1 described above, since the rate of change in moisture permeability is controlled to a predetermined value or less, it is preferable that the given performance is degraded even when exposed to sunlight. can be prevented, and the structure 21 such as concrete can be protected over a long period of time. In particular, the structure protection sheet 1 is given performance according to the characteristics of the structure 21 to follow cracks and expansions that occur in the structure 21, and permeation of deterioration factors such as water and chloride ions into the structure 21. In addition, the structure can be made permeable so that moisture and deterioration factors in the structure can be discharged. Since such a structure protection sheet 1 can be manufactured in a factory, it is possible to mass-produce high-quality sheets with stable characteristics. As a result, it can be constructed without relying on the skills of craftsmen, shortening the construction period and reducing labor costs.

[Method for manufacturing reinforced structure using structure protection sheet]
The method for manufacturing a reinforced structure using the structure protection sheet according to the present invention is a construction method using the structure protection sheet 1 according to the present invention, as shown in FIG. It is characterized in that the structure protection sheet 1 is pasted after the adhesive 23 is applied thereon. This construction method can easily bond the structure protection sheet 1 to the surface of the structure 21 . As a result, even an unskilled worker can provide the structure protection sheet 1 composed of a layer with a small thickness variation on the structure 21, thereby significantly reducing the construction period and extending the structure 21. can be protected over

FIG. 2 is an explanatory diagram of the construction method of the structure protection sheet 1 (manufacturing method of a reinforced structure). Construction forms the undercoat layer 22 on the surface of the structure 21, as shown in FIG. 2(A). The undercoat layer 22 can be formed by coating the structure 21 with a coating liquid obtained by mixing a resin such as an epoxy resin and a solvent, and then volatilizing and drying the solvent in the coating liquid. Examples of the solvent at this time include water and the like similar to those described above. Although the thickness of the undercoat layer 22 is not particularly limited, it can be in the range of 100 to 150 μm, for example. Since the undercoat layer 22 provided between the structure 21 and the adhesive 23 acts to enhance mutual adhesion, the structure protection sheet 1 can stably protect the structure 21 for a long period of time. If the structure 21 is cracked or damaged, it is preferable to provide the undercoat layer 22 after repairing it. Also, the repair is not particularly limited, but usually cement mortar, epoxy resin, or the like is used.

After forming the undercoat layer 22, an adhesive 23 is applied as shown in FIG. 2(B). Without drying the applied adhesive 23, the structure protection sheet 1 is adhered thereon as shown in FIG. 2(C). Examples of the adhesive 23 include urethane-based adhesives, epoxy-based adhesives, and adhesives using acrylic resins exhibiting rubber characteristics (for example, synthetic rubber containing acrylic acid ester as a main component). Among them, the adhesive 23 composed of the same resin component as the resin component constituting the polymer cement hardened layer 3 of the structure protection sheet 1 is more preferable because the adhesive strength with the polymer cement hardened layer 3 is increased. The thickness of the adhesive 23 is not particularly limited. The adhesive 23 is usually applied to concrete by means of brushing or spraying, and then naturally dried and hardened over time.

FIG. 3 is an explanatory diagram showing an example of applying the structure protection sheet 1 to the cast-in-place construction method. The cast-in-place method is a construction method in which a formwork 24 is formed at a work site, a concrete composition 21' is poured into the formwork 24, and left to harden to obtain a concrete structure 21. In this cast-in-place construction method, after forming the hardened concrete structure 21, the structure protection sheet 1 is attached to the surface of the hardened concrete structure 21, so that the structure 21 that is less likely to deteriorate can be obtained. In bonding, the undercoat layer 22 is applied to the surface of the concrete structure 21 and dried, and the adhesive 23 is applied thereon, after which the structure protection sheet 1 is bonded. After that, the structure protection sheet 1 is adhered by drying and curing the adhesive 23 by letting it stand naturally.

On the other hand, for the structure 21 that already has cracks, etc., the structure protection sheet 1 is attached by the same construction method as above after repairing the damaged portion. Thus, the life of the concrete structure 21 can be extended.

The present invention will be explained more specifically with examples and comparative examples.

(Example 1)
A release sheet made of PP-laminated paper and having a thickness of 130 μm was used. A resin layer was formed on this release sheet by the following method.
First, an emulsion composition containing 60 parts by mass of acrylic silicone resin, 25 parts by mass of titanium dioxide, 10 parts by mass of ferric oxide, and 5 parts by mass of carbon black was prepared. After the emulsion composition was applied onto the release sheet, it was cured by heat treatment to form a resin layer. The thickness of the resin layer was set to 0.1 mm.
Next, a polymer cement hardening layer was formed on the resin layer.
Specifically, "Aron Bull Coat A450X Setter" (manufactured by Toagosei Co., Ltd.) was used as the cement species, and "Acryset EMN-325E" (manufactured by Nippon Shokubai Co., Ltd.) was used as the resin component. The hardened polymer cement layer obtained by coating and drying the composition for forming a polymer cement layer in which these are mixed contains 0.08 parts by mass of the water-absorbing polymer per 100 parts by mass of the resin component, and the cement species is resin. It is a composite layer containing 50% by weight of the component.
After applying the composition for forming a polymer cement hardened layer onto the resin layer so that the thickness before drying is 1.0 mm on the resin layer. , dried at 80° C. for 50 minutes, and then aged at 80° C. and humidity of 50% RH for 3 days to form a hardened polymer cement layer 3 having a thickness of 1.29 mm.
Thus, a structure protection sheet having a total thickness of 1.39 mm was produced. In addition, this structure protection sheet was continuously produced in a factory controlled at about 25° C., and was wound into a roll while including a release sheet.

(Examples 2 to 12)
The structure was the same as in Example 1, except that the cement type and resin component were changed to the types shown in Table 1, and the blending amount of the water-absorbing polymer, the drying time, and the humidity during aging were changed as shown in Table 1. A protective sheet was prepared.

(Comparative Examples 1 to 6)
Structure protective sheets according to Comparative Examples 1 to 6 were produced in the same manner as in Examples 1 to 6, respectively, except that no water-absorbing polymer was added.

In Table 1, the cement type "Aronble" represents "Aronble Coat A-450X Setter" (manufactured by Toagosei Co., Ltd.), "Nippon Stucco" represents "Spring Coat Iron" (manufactured by Nippon Stucco Co., Ltd.), and the resin component " EMN” is “Acryset EMN-325E” (manufactured by Nippon Shokubai Co., Ltd.), “Aronble” is “Aronble Coat A-450 Base” (manufactured by Toagosei Co., Ltd.), “trowel” is “Spring Coat Iron” (Nippon Stucco Co., Ltd.) made).

[Measurement of moisture permeability]
The moisture permeability of the obtained structure protection sheets according to Examples and Comparative Examples was measured using the cup method (JIS Z0208:1976).
Next, the obtained structure protection sheets according to Examples and Comparative Examples were irradiated with light at a radiation intensity of 180 W/m ² using a xenon lamp for 72 hours, and then measured before and after light irradiation by the cup method in accordance with JIS Z0208:1976. The moisture permeability was measured, and the rate of change in moisture permeability was calculated.
Examples 1 to 6 (group 1) with the addition of 0.08 parts by mass of the water-absorbent polymer, Examples 7 to 12 (group 2) with the addition of 0.13 parts by mass, and Comparative Examples 1 to 6 (group 3 ), and the average value of the moisture permeability before and after light irradiation by the xenon lamp in each group was obtained. The results are shown in FIG.
As shown in FIG. 4, the average values of the rate of change in moisture permeability of Group 1 and Group 2 according to the example to which the water-absorbing polymer was added were 32.1% and 15.0%, and the water-absorbing polymer was added. The average value of the rate of change in moisture permeability of Group 3 according to the comparative example, which did not have a water vapor transmission rate, was 59.1%. In addition, the rate of change in moisture permeability of the structure protection sheets according to the examples was all 35% or less.

1 structure protection sheet 2 resin layer 3 polymer cement hardening layer 5 primer layer 21 structure (concrete)
21' concrete composition (structure-forming composition)
22 Undercoat layer
23 Adhesive
24 Formwork

Claims

A structure protection sheet comprising a polymer cement hardened layer provided on the structure side and a resin layer provided on the polymer cement hardened layer,
A structure protection sheet having a rate of change in moisture permeability of 35% or less before and after being irradiated with light from a xenon lamp having a radiation intensity of 180 W/m 2 for 72 hours.
The structure protection sheet according to claim 1, wherein the polymer cement hardened layer is subjected to water absorption treatment.
The water absorption treatment includes a method of adding a water absorbing polymer to the polymer cement hardened layer, a method of adding an inorganic water absorbing substance to the polymer cement hardened layer, and an aging treatment in producing the polymer cement hardened layer. A method in which the heat treatment for forming the resin layer is performed in a high-humidity environment, a method in which the polymer cement hardened layer is provided with a water-containing sheet that absorbs water, and a structure protection sheet is applied. 3. The structure protection sheet according to claim 2, wherein the method is any one selected from the group consisting of wet curing afterward.
The structure protection sheet according to claim 1, 2 or 3, wherein the polymer cement hardening layer is a layer containing a cement component and a resin, and the resin is contained in an amount of 10% by weight or more and 40% by weight or less.
A method for manufacturing a reinforced structure using the structure protection sheet according to claim 1, 2, 3 or 4, comprising applying an adhesive onto the structure and then laminating the structure protection sheet together. A method of manufacturing a reinforced structure, characterized by:
The method for manufacturing a reinforced structure according to claim 5, wherein an undercoat layer is provided between the structure and the adhesive.