Structure protection sheet and method for manufacturing reinforced structure

Abstract

To provide a structure protection sheet superior in strength and capable of protecting a structure for a long time while significantly reducing the construction period when installing a protection sheet over the surface of a concrete structure.SOLUTION: A structure protection sheet is used by being laminated over the surface of the structure in which an adhesion layer, a polymer cement hardening layer, and a resin layer are provided in this order.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a structure protection sheet and a method for manufacturing a reinforced structure. More specifically, the present invention relates to a structure protection sheet that can significantly reduce the construction time required to provide a protective layer on the surface of a structure such as concrete and can protect the structure for a long period of time, and a method for manufacturing a reinforced structure using the structure protection sheet. [Background technology]

[0002] Civil engineering structures such as road bridges, tunnels, river management facilities such as water gates, sewer pipes, and quay walls undergo repair and reinforcement work as they age. Repair work involves repairing missing or weak parts and then applying multiple coats of paint. Meanwhile, reinforcement work involves applying multiple coats of reinforcing paint to the entire area that needs reinforcement.

[0003] The multiple coats applied during such repair and reinforcement work involve applying a primer coat, intermediate coat, and top coat to concrete in that order, for example. However, the intermediate coats and each of these coating processes cannot usually be applied consecutively in order to allow the paint to dry. For example, applying five layers of paint (primer coat, first intermediate coat, second intermediate coat, first top coat, and second top coat) takes at least five days. Furthermore, because the painting is done outdoors, it is dependent on the weather; in rainy weather, the paint may not dry sufficiently or the painting work may not even be possible. This makes it difficult to shorten the construction period, which increases labor costs. Furthermore, the quality of the work and the coating (film thickness, surface roughness, moisture content, etc.) is often affected by the external environment (humidity, temperature, etc.) during the painting process, making it difficult to achieve consistent results.

[0004] Furthermore, painting is done by troweling or spraying, but achieving stable repair or reinforcement through uniform application of paint largely depends on the skill of the craftsman. Therefore, the quality of the coating film varies depending on the skill of the craftsman. Furthermore, with the aging of construction workers and a declining population, the number of workers engaged in concrete repair and reinforcement work is decreasing, so there is a demand for a simpler repair method that can be performed by less skilled craftsmen.

[0005] As a technology for solving these problems, for example, Patent Document 1 proposes a sheet and method that is simple, low-cost, shortens construction time, and reliably prevents concrete deterioration. This technology is a concrete repair method in which a concrete repair sheet that includes an intermediate layer with a resin film and surface layers made of a fabric material laminated on both sides of the intermediate layer via an adhesive resin is attached to the concrete surface to be repaired with a construction adhesive, and then paint is applied to the surface layer on the side opposite the concrete surface of the attached concrete repair sheet.

[0006] Improvements have also been made to coating materials. For example, Patent Document 2 proposes a method for protecting concrete structures using a coating material that prevents alkali-aggregate reaction, has excellent conformability to cracks in concrete structures, does not cause swelling of the coating film even when the temperature rises after coating film formation, and makes it possible to prevent concrete from peeling off. This technology involves forming a surface conditioner coating film on the surface of the concrete structure, and then forming a coating film on the surface of that coating film. The surface conditioner 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 surface conditioner 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 and a salt barrier property of 10 -2 ~10 -4 mg / cm 2 .day, water vapor permeability is 5g / m·day or more, and the membrane thickness is 100 to 5000μm. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-144360 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-16886 Summary of the Invention [Problem to be solved by the invention]

[0008] Conventional concrete repair sheets such as those described in Patent Document 1 have issues to be resolved, such as differences in adhesive strength between the substrate and other layers (for example, the adhesive layer and reinforcing member), differences in elongation of the substrate, adhesive layer, and reinforcing member, and problems with the adhesive strength between the adhesive layer and concrete. Specifically, the substrate and reinforcing member are bonded together with the adhesive layer, but if stress is applied to the concrete repair sheet during or after application, differences in elongation of the substrate, adhesive layer, and reinforcing member can cause peeling at the layer interface due to the difference in adhesive strength between the substrate and adhesive layer and the adhesive strength between the adhesive layer and reinforcing member.

[0009] Furthermore, the adhesive layer on the concrete repair sheet is softened by heating or other means before being attached to the concrete, but if sufficient adhesive strength is not obtained, the concrete repair sheet may peel off from the surface of the concrete and no longer function as a repair sheet. Furthermore, concrete after application of the concrete repair sheet has sometimes swelled over time, and this phenomenon is thought to be due to the water vapor inside the concrete being unable to escape due to the presence of the repair sheet, which has low water vapor permeability.

[0010] Furthermore, as explained in the Background Art section above, the method of forming a coating film by coating on-site requires one day for each coating layer, and for example, it takes six days to form a six-layer coating film from the undercoat to the topcoat. In addition, there are problems such as variations in film thickness and difficulty in stabilizing quality and characteristics such as surface roughness and moisture content.

[0011] Furthermore, since the objects to be repaired with concrete repair sheets are usually large concrete components such as road bridges, tunnels, river management facilities such as sluice gates, sewerage pipes, and civil engineering structures such as bay walls, the concrete repair sheet itself is required to have sufficient strength (this refers to tensile strength, flexural strength, hardness, surface strength, punching strength, toughness, etc., and the same applies hereinafter in this specification), but there is a problem in that it is difficult to say that conventional concrete repair sheets have sufficient strength.

[0012] The present invention has been made to solve the above-mentioned problems, and its object is to provide a structure protection sheet that can significantly reduce the construction time required to apply a protection sheet to the surface of a structure such as concrete, can protect the structure for a long period of time, and has excellent strength, as well as a method for manufacturing a reinforced structure using the structure protection sheet. [Means for solving the problem]

[0013] The present inventors have conducted research into a concrete protection sheet that can stably protect concrete for a long period of time without relying on an application method that involves forming a layer on the surface of concrete using a coating means. As a result, we have developed a concrete protection sheet that provides performance tailored to the characteristics of concrete, specifically, conformability to cracks and expansion in concrete, waterproofing to prevent the penetration of deteriorating factors such as water and chloride ions into concrete, salt insulation, neutralization prevention, and water vapor permeability to expel moisture from concrete as water vapor, while also providing a layer that ensures the strength of the concrete protection sheet itself. Furthermore, we have discovered that by forming an adhesive layer in advance on the surface of such a concrete protection sheet that will be attached to the concrete surface, it can be attached to the concrete via the adhesive layer, eliminating the need to apply an adhesive to the concrete structure surface at the work site and forming an adhesive layer, thereby significantly improving work efficiency, thereby completing the present invention. This technical concept can also be applied as a structure protection sheet to structures other than concrete.

[0014] (1) The structure protection sheet according to the present invention is a structure protection sheet that is used by being attached to the surface of a structure, and is characterized by comprising an adhesive layer, a hardened polymer cement layer, and a resin layer provided in this order.

[0015] According to this invention, the hardened polymer cement layer provided on the structure side has excellent adhesion to the structure and can also be imparted with excellent performance such as punching strength. Furthermore, the structural protection sheet can be mass-produced using coating and drying processes on a factory production line, which reduces costs, significantly reduces on-site construction time, and enables long-term protection of structures. Furthermore, since an adhesive layer is formed in advance on the surface of the hardened polymer cement layer, it is possible to attach the structure protection sheet to the surface of the structure via the adhesive layer without applying an adhesive at the work site to form an adhesive layer, resulting in extremely high work efficiency.

[0016] In the structure protection sheet according to the present invention, the adhesive layer is preferably made of an acrylic pressure-sensitive adhesive.

[0017] Acrylic pressure-sensitive adhesives offer a high degree of freedom in material design and are also excellent in transparency, weather resistance, and heat resistance, allowing the structure protection sheet of the present invention to more suitably protect the structure.

[0018] The structure protection sheet according to the present invention preferably has a punching strength of 1.5 kN or more in the punching test specified in JSCE-K-533.

[0019] According to this invention, the structure protection sheet of the present invention can suitably prevent problems such as concrete or the like peeling off from the surface of a structure.

[0020] The structure protection sheet according to the present invention has an adhesive strength of 0.5 N / mm when attached to the surface of a structure via an adhesive layer. 2 It is preferable that this is equal to or greater than this.

[0021] According to this invention, the structure protection sheet of the present invention can provide strong protection of the surface of a structure for a long period of time.

[0022] In the structure protection sheet according to the present invention, the adhesive layer preferably has a thickness of 20 to 500 μm.

[0023] According to this invention, the adhesive strength when attached to the surface of a structure can be made excellent, and the structure protection sheet according to the present invention can provide strong protection of the surface of the structure for a long period of time.

[0024] In the structure-protecting sheet according to the present invention, the cured polymer cement layer may be 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 20% by weight or more and 30% by weight or less of the resin.

[0025] According to this invention, the hardened polymer cement layer has excellent conformability and compatibility, and therefore the layer itself has excellent adhesion. Furthermore, the cement component contained in the hardened polymer cement layer on the structure side acts to enhance adhesion to structures such as concrete.

[0026] The structure protection sheet according to the present invention preferably further comprises a mesh layer.

[0027] According to this invention, the presence of the mesh layer can impart excellent properties such as strength to the structure protection sheet according to the present invention.

[0028] (2) The method for manufacturing a reinforced structure according to 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 attached to the surface of the structure via the adhesive layer.

[0029] According to this invention, a structure protection sheet is used that is composed only of layers that do not include a substrate or reinforcing member, so that it can be easily attached to the surface of a structure, and the structure protection sheet can be attached to the surface of the structure via an adhesive layer at the work site. As a result, even an unskilled worker can stably apply a structure protection sheet with excellent strength to the surface of the structure, significantly reducing the construction period and providing long-term protection for the structure. [Effects of the Invention]

[0030] The present invention provides a structure protection sheet capable of protecting structures such as concrete over the long term, and a method for manufacturing a reinforced structure using the structure protection sheet. In particular, the present invention provides a structure protection sheet that can be easily applied to the surface of a structure by imparting performance to the structure's characteristics, adapting to cracks and expansion that occur in the structure, preventing the penetration of deterioration factors such as water and chloride ions into the structure, imparting permeability that allows moisture and deterioration factors to be expelled from the structure, and improving strength. Furthermore, the present invention has the advantage of improving the stability and uniformity of quality compared to layers that have previously been formed by hand application. [Brief explanation of the drawings]

[0031] [Figure 1] 1(A) and 1(B) are cross-sectional views showing an example of the structure protection sheet according to the present invention. [Figure 2] 1(A) and 1(B) are schematic diagrams showing how the structure protection sheet according to the present invention is attached to a structure. [Figure 3] 3(A) and 3(B) are cross-sectional views showing another example of the structure protection sheet according to the present invention. [Figure 4] 1(A) and 1(B) are schematic diagrams showing an example of a mesh layer of a structure protection sheet according to the present invention. [Figure 5] FIG. 10 is an explanatory diagram showing an example of applying a structure protection sheet to a cast-in-place construction method. [Figure 6] 1 is a schematic diagram showing an example of embossing a resin layer of a structure protection sheet according to the present invention. [Figure 7] 1A to 1C are explanatory diagrams illustrating a method for forming a concave-convex shape on a resin layer of a structure protection sheet. DETAILED DESCRIPTION OF THE INVENTION

[0032] The structure protection sheet and the method for inspecting a structure using the same according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following description and drawings, and various modifications are possible as long as the technical features are maintained.

[0033] [Structure protection sheet] The structure protection sheet of the present invention is used by being attached to the surface of a structure, and when attached to the structure, a resin layer is provided on the outermost surface, and a pattern for detecting deformation is formed on the surface of the resin layer. As shown in Fig. 1, such a structure protection sheet 1 according to the present invention has an adhesive layer 5, a cured polymer cement layer 2, and a resin layer 3 provided in this order. Both the cured polymer cement layer 2 and the resin layer 3 may be formed as single layers, as shown in Fig. 1(A), or may be formed as a laminate, as shown in Fig. 1(B). Depending on the desired performance, another layer may be provided between the cured polymer cement layer 2 and the resin layer 3.

[0034] The structure protection sheet 1 according to the present invention has a water vapor permeability of 10 to 50 g / m 2It is preferable that the water vapor permeability is within the predetermined range. Because the polymer cement cured layer 2 contains cement components, it can be expected to have a certain level of water vapor permeability. However, it is expected that the resin layer 3 provided on the polymer cement cured layer 2 will have a poor water vapor permeability. However, this problem does not occur in the present invention. Since the water vapor permeability of the entire structure protection sheet 1 is within the predetermined range, water vapor inside the sheet can be efficiently permeated and released to the outside after application to a structure such as concrete. This effectively prevents the occurrence of blisters and also prevents a decrease in adhesiveness. The advantage of having a water vapor permeability within the predetermined range is that the structure allows steam to easily escape, which tends to inhibit corrosion of metals (e.g., rebar) in the structure. Furthermore, when the structure protection sheet 1 is applied to a structure on a rainy day, the surface of the structure becomes wet and the structure itself is moistened during application. However, the water vapor permeability of the structure protection sheet 1 allows moisture that has soaked into the structure after application (after the reinforced structure is manufactured) to easily escape to the outside. Furthermore, concrete immediately after hardening contains a large amount of moisture inside, and the structure protection sheet 1 according to the present invention can also be suitably used for such concrete. Another advantage of the structure protection sheet 1 according to the present invention is that its water vapor permeability can be controlled, so that it can be attached to the surface of a structure even when the cement of the structure is not yet hardened. In other words, if water is rapidly removed when the cement is molded and hardened, the cement becomes porous, which tends to reduce the strength of the structure. However, by attaching the structure protection sheet 1 according to the present invention to the cement before hardening, the speed at which water is removed as the cement hardens can be controlled, which has the advantage of making it easier to avoid the formation of the porous structure. The water vapor permeability is 10g / m 2 If the applied time is less than 50 g / m, the structure protection sheet 1 according to the present invention will not be able to sufficiently transmit water vapor, and swelling and other phenomena after application to the structure may not be prevented, resulting in insufficient adhesiveness. 2If the water vapor permeability exceeds 1000 times the water vapor permeability, the speed of water removal during hardening of the cement will be excessively fast, which may cause the hardened cement to become porous. The preferred range of the water vapor permeability is 20 to 50 g / m 2 .day. The structure protection sheet 1 according to the present invention having such a water vapor permeability can be obtained, for example, by using a polymer cement cured layer 2 described below and a resin having a predetermined water vapor permeability for the resin layer 3. The water vapor transmission rate in the present invention can be measured by the method described below.

[0035] Furthermore, the structure protection sheet 1 according to the present invention preferably has a sulfuric acid penetration depth of 0.1 mm or less after being wrapped in a building concrete building block and immersed in a 5% aqueous sulfuric acid solution for 30 days. If the sulfuric acid penetration depth exceeds 0.1 mm, the sulfuric acid resistance of the structure protection sheet 1 according to the present invention may be insufficient, making it unsuitable for use in structures prone to corrosion caused by sulfuric acid, such as sewer concrete structures. A more preferred upper limit of the sulfuric acid penetration depth is 0.01 mm. The sulfuric acid penetration depth in the present invention can be measured by the method described in the examples below.

[0036] Furthermore, the structure protection sheet according to the present invention may be used in a state in which two or more layers are stacked together. A structure already protected by the structure protection sheet according to the present invention can be further protected by stacking layers, so that, for example, when two structure protection sheets according to the present invention are attached side by side, another structure protection sheet according to the present invention can be attached so as to cover the boundary between these structure protection sheets. In the structure protection sheet 1 according to the present invention, the polymer cement cured layer 2 contains cement and a resin component, and therefore exhibits favorable adhesion to the resin layer 3 of the structure protection sheet 1 according to the present invention that has been previously attached to a structure. Therefore, the structure protection sheet 1 according to the present invention can be favorably used in an overlapping state.

[0037] The structure protection sheet 1 of the present invention preferably has a tear load of 3 to 20 N, measured according to the tear load test section of JIS K 6781. Such a tear load allows the sheet to tear appropriately when the protected structure collapses or falls, preventing a chain reaction of collapses or falls. Furthermore, even in cases where it becomes necessary to remove only a portion of the protected structure, the sheet can be torn at any location, allowing for partial removal of the structure. If the tear load is less than 3 N, it becomes difficult to protect the structure itself, and if it exceeds 20 N, tearing may not occur at the appropriate time. A more preferred range of the tear load is 5 to 15 N. The tear load in the present invention can be measured by the method described in the Examples below.

[0038] The structure protection sheet 1 according to the present invention preferably has a thickness distribution within ±100 μm. Because the thickness distribution of this structure protection sheet 1 is within the above range, even an unskilled worker can stably form a layer with little thickness variation on the surface of a structure. Furthermore, controlling the thickness distribution within the above range facilitates uniform reinforcement of the structure. The polymer cement cured layer 2 provided on the structure side has excellent adhesion to the structure, and the resin layer 3 provided on the polymer cement cured layer 2 can easily be endowed with excellent properties such as waterproofing, salt protection, and neutralization prevention. Furthermore, the structure protection sheet 1 according to the present invention can be mass-produced using coating and drying processes on a factory production line, thereby reducing costs, significantly reducing on-site work time, and achieving long-term protection of structures. Furthermore, because the structure protection sheet 1 according to the present invention is provided with the adhesive layer 5, there is no need to apply an adhesive to form an adhesive layer at the work site, and even non-skilled craftsmen can easily attach it to the surface of a structure via an adhesive layer of uniform thickness. As a result, the construction time required for attaching it to the surface of a structure can be significantly reduced, and the structure can be protected for a long period of time.

[0039] Specific examples of each component will be described in detail below.

[0040] (structure) As shown in FIG. 2(B), the structure 21 is a mating member to which the structure protection sheet 1 according to the present invention is applied. The structure 21 may be a structure made of concrete. The concrete is generally obtained by pouring and curing a cement composition containing at least cementitious inorganic materials, aggregate, admixtures, and water. Such concrete is widely used in civil engineering structures such as road bridges, tunnels, river management facilities such as water gates, sewerage pipes, and harbor quays. In the present invention, applying a structure protection sheet 1 to a concrete structure 21 has the particular advantages of being able to accommodate cracks and expansion that occur in the concrete, preventing deterioration factors such as water and chloride ions from penetrating into the concrete, and allowing moisture in the concrete to be expelled as water vapor.

[0041] (polymer cement hardened layer) As shown in FIGS. 1 and 2, the polymer cement cured layer 2 is disposed on the structure 21 side via an adhesive layer 5. This polymer cement cured layer 2 may be, for example, a single layer without multiple coatings as shown in FIG. 1(A), or may be a multi-layer structure with multiple coatings as shown in FIG. 1(B). The choice of whether to form a single layer or a multi-layer structure is determined arbitrarily based on factors such as the overall thickness, the desired functionality (e.g., conformability, adhesion to the structure), the factory production line, and production costs. For example, if the production line is too short to achieve the desired thickness with a single layer, two or more layers can be applied in multiple layers. For example, when applying two layers in multiple layers, the first layer is dried and then the second layer is applied. Furthermore, polymer cement cured layer 2 may be configured by laminating layers of different properties. For example, by forming a layer with a higher resin content on the resin layer 3 side, the layer with a higher resin content will adhere to the resin layer, and the layer with a higher cement content will adhere to the concrete structure, resulting in extremely excellent adhesion to both.

[0042] The hardened polymer cement layer 2 is preferably a layer containing a cement component and a resin. More specifically, it is obtained by forming a resin containing a cement component (resin component) into a paint and applying the paint. Examples of the cement component include various cements, limestones containing calcium oxide, and clays containing silicon dioxide. Cement is preferred, and examples include Portland cement, alumina cement, high-early-strength cement, and fly ash cement. The cement to be selected depends on the properties the polymer cement hardened layer 2 should have, for example, taking into consideration the degree of conformability to the concrete structure 21. Portland cement as specified in JIS R5210 is particularly preferred.

[0043] 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 ester as a main component), etc. From the viewpoint of improving adhesion between the hardened polymer cement layer 2 and the resin layer 3, it is preferable that such a resin component be the same as the resin component constituting the resin layer 3 described below. The resin component may be any of a thermoplastic resin, a thermosetting resin, and a photocurable resin. The term "hardened" in polymer cement hardened layer 2 does not mean that the resin component is limited to a resin that hardens and polymerizes, such as a thermosetting resin or a photocurable resin, but means that any material that hardens when it becomes the final layer may be used.

[0044] The content of the resin component is adjusted appropriately depending on the materials used, etc., but is preferably 10% by mass or more and 40% by weight or less of the total amount of the cement component and resin component. If it is less than 10% by weight, adhesion to the resin layer 3 may decrease and it may become difficult to maintain the polymer cement cured layer 2 as a layer. If it exceeds 40% by weight, adhesion to the concrete structure 21 may be insufficient. From the above perspectives, the content of the resin component is more preferably 15% by weight or more and 35% by weight or less, and even more preferably 20% by weight or more and 30% by weight or less.

[0045] The coating material for forming the polymer cement cured layer 2 is a coating liquid obtained by mixing a cement component and a resin component in a solvent. The resin component is preferably an emulsion. For example, an acrylic emulsion is a polymer fine particle obtained by emulsion polymerization of a monomer such as an acrylic acid ester using an emulsifier. One preferred example is an acrylic acid polymer emulsion obtained by polymerizing a monomer or a monomer mixture containing one or more acrylic acid esters and methacrylic acid esters in water containing a surfactant. The content of the acrylic ester and the like constituting the acrylic emulsion is not particularly limited, but is selected within the range of 20 to 100% by mass. Furthermore, the surfactant is also blended in an amount as needed, and the amount is not particularly limited, but the surfactant is blended in an amount sufficient to form an emulsion.

[0046] The polymer cement cured layer 2 is formed by applying the coating liquid to a release sheet and then drying and removing the solvent (preferably water). For example, a mixed composition of a cement component and an acrylic emulsion is used as the coating liquid to form the polymer cement cured layer 2. The resin layer 3 may be formed on the release sheet after the polymer cement cured layer 2 has been formed, or the resin layer 3 may be formed on the release sheet after the polymer cement cured layer 2 has been formed, or the polymer cement cured layer 2 may be formed on the release sheet after the resin layer 3 has been formed. In the present invention, when a design is to be imparted, for example, the structure protection sheet 1 may be produced by embossing or matting (imparting a textured shape) the release sheet, and then forming the resin layer 3 (which may be a single layer or a multi-layer structure of two or more) and the polymer cement cured layer 2 (which may be a single layer or a multi-layer structure of two or more) on top of the release sheet in this order, and then imparting the design to the resin layer 3.

[0047] The thickness of the polymer cement hardened layer 2 is not particularly limited and can be arbitrarily determined depending on the type of use of the structure 21 (such as road bridges, tunnels, river facilities such as water gates, sewer pipes, harbor quays, bridges, parapets, highway sidewalls, sewer pipes (inner surfaces, outer surfaces, and joints), sewage facilities (sewage treatment facilities and irrigation channels), underwater facilities, civil engineering structures such as wiring tunnels in coastal areas, dam spillways, and manhole inner walls, as well as buildings such as concrete roofs, galvanized iron roofs, concrete rooftops, building piping, ALC panels, indoor flooring, and the inner and outer surfaces of chimneys), age, and shape. The specific thickness of the polymer cement hardened layer 2 can be, for example, in the range of 0.5 mm to 1.5 mm. For example, when the thickness is set to 1 mm, the thickness variation is preferably within ±100 μm. Such a thickness precision is impossible to achieve by on-site coating and can be achieved by stable coating on a factory production line. Even when the thickness is greater than 1 mm, the thickness variation can be kept within ±100 μm. Furthermore, when the thickness is less than 1 mm, the thickness variation can be further reduced.

[0048] The presence of cement components allows water vapor to easily permeate through this polymer cement hardened layer 2. The water vapor permeability at this time is, for example, 20 to 60 g / m 2 The average life span is approximately .3 days. Furthermore, the cement component has good compatibility with the cement components constituting concrete, for example, and can be made to have excellent adhesion to the concrete surface. As shown in FIG. 1, the structure protection sheet 1 according to the present invention has an adhesive layer 5, and the cured polymer cement layer 2 containing the cement component adheres to the adhesive layer 5 with good adhesion. Furthermore, because this cured polymer cement layer 2 is extensible, it can follow changes in the concrete even if cracks or expansion occur in the structure 21.

[0049] (mesh layer) The present invention preferably further comprises a mesh layer. When the structure protection sheet of the present invention is used to repair large concrete members such as road bridges, tunnels, river management facilities such as water gates, sewerage pipes, bay walls and other civil engineering structures, the structure protection sheet of the present invention itself is required to have sufficient strength (this refers to tensile strength, flexural strength, hardness, surface strength, punching strength toughness, etc., and the same applies hereinafter in this specification).However, by further providing the mesh layer as described above, the structure protection sheet of the present invention can have sufficient strength to withstand the repair of large concrete members such as those described above.

[0050] As shown in FIG. 3(A), it is preferable that the structure protection sheet 1 according to the present invention has a mesh layer 7 at the interface between the hardened polymer cement layer 2 and the resin layer 3, as this provides excellent adhesive strength. The adhesive strength is determined by attaching the polymer cement cured layer 2 side of the structure protection sheet 1 according to the present invention to the surface of concrete via the adhesive layer 5, fixing a tensile jig to the surface of the resin layer 3, and pulling the tensile jig toward the side opposite the concrete at a speed of 1500 n / min to measure the strength at which tensile delamination occurs.

[0051] 3(B), mesh layer 7 may be present inside hardened polymer cement layer 2. Mesh layer 7 may be disposed on the surface of hardened polymer cement layer 2 opposite to the surface that contacts resin layer 3, but mesh layer 7 is preferably embedded inside hardened polymer cement layer 2. By embedding mesh layer 7 inside hardened polymer cement layer 2, the contact area between mesh layer 7 and hardened polymer cement layer 2 increases, which facilitates excellent adhesive strength between them and ensures the overall strength of hardened polymer cement layer 2. If mesh layer 7 is not embedded inside hardened polymer cement layer 2, peeling is likely to occur at the interface between mesh layer 7 and hardened polymer cement layer 2. When mesh layer 7 is present inside hardened polymer cement layer 2, mesh layer 7 may be present at a position halfway through the thickness of hardened polymer cement layer 2, but it is preferable that mesh layer 7 be present closer to resin layer 3. When mesh layer 7 is present in hardened polymer cement layer 2 closer to resin layer 3, the adhesive strength is improved by an average of 1.3 times.

[0052] In the present invention, it is preferable that the mesh layer 7 is impregnated with the material constituting the hardened polymer cement layer 2 (for example, a cement component or a resin component). The state in which mesh layer 7 is impregnated with the material that constitutes polymer cement cured layer 2 means that the material that constitutes polymer cement cured layer 2 is filled between the fibers that constitute mesh layer 7, and this impregnation state tends to provide extremely excellent adhesive strength between mesh layer 7 and polymer cement cured layer 2. In addition, the interaction between mesh layer 7 and the material of polymer cement cured layer 2 tends to be stronger, which tends to improve the strength of structure protection sheet 1.

[0053] As shown in FIG. 4, the mesh layer 7 may have a structure in which warp and weft fibers are arranged in a lattice pattern. The fibers are preferably composed of at least one type of fiber selected from the group consisting of polypropylene fibers, vinylon fibers, carbon fibers, aramid fibers, glass fibers, polyester fibers, polyethylene fibers, nylon fibers, and acrylic fibers, and among these, polypropylene fibers and vinylon fibers are preferably used. The shape of the mesh layer 7 is not particularly limited, and in addition to the biaxially woven fabric shown in FIG. 6, any mesh layer 7 such as a triaxially woven fabric can be used. The mesh layer 7 for preventing concrete spalling can be made of high-strength vinylon mesh for civil engineering, vinylon for agriculture, or cheesecloth made of polyester or the like.

[0054] The mesh layer 7 preferably has a line pitch of 50 mm to 1.2 mm (line density of 0.2 to 8.0 lines / cm). If the pitch is 1.2 mm or less, the polymer cement layers above and below the mesh may not be bonded properly, resulting in insufficient surface strength of the structure protection sheet 1. If the line pitch exceeds 50 mm, the surface strength of the structure protection sheet 1 will not be adversely affected, but the tensile strength may be reduced. In the structure protection sheet 1 according to the present invention, there is a trade-off between tensile strength and surface strength, and the mesh layer 7 suitable for application to the present invention has a line pitch in the range of 50 mm to 1.2 mm.

[0055] Mesh layer 7 may be large enough to cover the entire surface of hardened polymer cement layer 2 when viewed from the top side of hardened polymer cement layer 2 , or may be smaller than hardened polymer cement layer 2 . That is, the area of ​​mesh layer 7 in plan view may be the same as or smaller than the area of ​​cured polymer cement layer 2 in plan view, but the area of ​​mesh layer 7 in plan view is preferably 60% to 95% of the area of ​​cured polymer cement layer 2 in plan view. If the area is less than 60%, the strength of the structure protection sheet of the present invention may be insufficient, and strength variations may occur. If the area is more than 95%, in a configuration in which cured polymer cement layers 2 are laminated via mesh layer 7, the adhesive strength between the cured polymer cement layers 2 may be poor, increasing the risk of peeling at the cured polymer cement layer 2 when the structure protection sheet of the present invention is applied to a structure. The area of ​​mesh layer 7 and other layers in plan view can be measured by a known method.

[0056] (resin layer) As shown in Figures 1 and 2, the resin layer 3 is disposed on the opposite side of the structure 21 and appears on the surface. This resin layer 3 may be, for example, a single layer as shown in Figure 1(A) or a laminate consisting of at least two layers as shown in Figure 1(B). The decision as to whether to form a single layer or a laminate is based on factors such as the overall thickness, the functions to be imparted (waterproofing, salt blocking, neutralization prevention, water vapor permeability, etc.), the length of the factory production line, and production costs. For example, if the production line is too short to achieve the required thickness with a single layer, two or more layers can be applied in layers. In this case, the first layer is dried and then the second layer is applied. The second layer is then dried.

[0057] The resin layer 3 is obtained by applying a coating material that is flexible, can conform to cracks and fissures that occur in the concrete, and has excellent waterproofing, salt-blocking properties, neutralization prevention properties, and water vapor permeability. Examples of resins that make up the resin layer 3 include acrylic resins that exhibit rubber properties (e.g., synthetic rubbers containing acrylic esters as their main component), acrylic urethane resins, acrylic resins, fluororesins, flexible epoxy resins, and polybutadiene rubber. This resin material is preferably the same as the resin components that make up the polymer cement cured layer 2 described above. Resins containing elastic film-forming components such as rubber are particularly preferred.

[0058] Among these, acrylic resins exhibiting rubber properties are preferably made from an aqueous emulsion of an acrylic rubber copolymer, due to their excellent safety and coatability. The proportion of the acrylic rubber copolymer in the emulsion is, for example, 30 to 70 mass%. The acrylic rubber copolymer emulsion can be obtained, for example, by emulsion polymerization of monomers in the presence of a surfactant. The surfactant can be any of anionic, nonionic, and cationic.

[0059] In the structure protection sheet according to the present invention, the resin layer 3 is preferably composed of a resin that exhibits excellent water vapor permeability. By providing a resin layer 3 composed of such a resin, the water vapor permeability of the structure protection sheet according to the present invention can be set within the above-mentioned range.

[0060] The coating material for forming the resin layer 3 is prepared by preparing a mixed coating liquid of a resin composition and a solvent, applying the coating liquid to a release sheet, and then drying and removing the solvent to form the resin layer 3. The solvent may be water or an aqueous solvent, or an organic solvent such as xylene or mineral spirits. In the examples described below, an aqueous solvent is used, and the resin layer 3 is prepared from an acrylic rubber composition. The order of the layers formed on the release sheet is not limited, and may be, for example, the order of resin layer 3 followed by the hardened polymer cement layer 2, as described above, or the order of hardened polymer cement layer 2 followed by the resin layer 3.

[0061] The thickness of the resin layer 3 is set arbitrarily depending on the type of use of the structure 21 (such as a road bridge, tunnel, river management facility such as a water gate, a sewer pipe, or a civil engineering structure such as a port quay), its age, shape, etc. As an example, the thickness is set to any value within a range of 50 to 150 μm, and it is preferable that the thickness variation is within ±50 μm. Such a thickness precision is impossible to achieve by on-site coating, but can be achieved reliably on a factory production line.

[0062] The resin layer 3 has high waterproofing properties, salt blocking properties, and neutralization prevention properties, but is preferably permeable to water vapor. In this case, the water vapor transmission rate is, for example, 10 to 50 g / m 2 , which is the same as that of the structure protection sheet 1 according to the present invention. 2 It is desirable to adjust the temperature appropriately so that the temperature is .day. This allows the structure protection sheet 1 to have high waterproofing, salt protection, and carbonation prevention properties, as well as a predetermined water vapor permeability. Furthermore, by being composed of the same type of resin component as the polymer cement hardened layer 2, it is possible to achieve good compatibility with the polymer cement hardened layer 2 and excellent adhesion. The water vapor permeability was measured in accordance with JIS Z0208 "Test method for moisture permeability of moisture-proof packaging materials."

[0063] Furthermore, the resin layer 3 may contain a pigment from the viewpoint of increasing the color variation of the structure-protecting sheet 1 according to the present invention. The resin layer 3 may also contain an inorganic substance. By containing an inorganic substance, scratch resistance can be imparted to the resin layer 3. The inorganic substance is not particularly limited, and examples thereof include conventionally known materials such as metal oxide particles of silica, alumina, titania, etc. Furthermore, the structure protection sheet according to the present invention preferably exhibits a contaminant removal rate of 95% or more when the surface of the resin layer 3 opposite the polymer cement cured layer 2 is contaminated with carbon particle-containing oil, then placed vertically and cleaned by forcefully spraying tap water horizontally from a hose from a distance of approximately 2 meters. This provides excellent cleaning properties for the surface of the resin layer 3, making it an ideal repair sheet for structures where contaminants easily adhere, such as highway walls and tunnel walls. If the contaminant removal rate is less than 95%, the stain resistance will be insufficient, and the highway walls and tunnel walls will likely appear "dirty." On the other hand, while a higher contaminant removal rate is preferable, it is typically 98% or less. The structure protection sheet 1 of the present invention having such a contaminant removal rate can be obtained, for example, by selecting a material that easily removes contaminants, such as an acrylic silicone resin, as the resin for the resin layer, or by incorporating into the resin layer a material (antifouling agent) that easily removes contaminants, such as silicone resin or silicon microparticles. The evaluation of the staining property in the present invention can be carried out by the method described in the examples below. The resin layer 3 may also contain additives that can impart various functions to the resin layer 3. Examples of such additives include cellulose nanofibers.

[0064] [Design-imparting treatment] In the structure protection sheet according to the present invention, a design is preferably imparted to either one surface of the resin layer 3. Here, "either one surface" refers to the surface on the side of the hardened polymer cement layer 2 or the opposite surface. The design is preferably imparted by providing a textured shape or by printing. The treatment for imparting the design is not particularly limited, and suitable examples include embossing, matte treatment (matt treatment), mirror treatment (gloss treatment) on the surface of the resin layer, or printing on the surface of the resin layer.

[0065] The embossing process is a process for imparting a desired uneven shape to the surface of the resin layer 3. For example, an uncured resin layer 3' is fed onto an embossing roll 10 having unevenness formed on the roll surface corresponding to the unevenness to be imparted, as shown in Figure 6, and the surface of the uncured resin layer 3' is pressed against the roll 10 to transfer the unevenness of the embossing roll 10 to the surface of the uncured resin layer 3', and then the uncured resin layer 3' is cured to form the resin layer 3. The shape of the projections and recesses of the embossing roll is not particularly limited and may be appropriately selected depending on the desired design. Other conditions for the embossing treatment may be the same as those conventionally known for embossing a resin film. Furthermore, the method for forming the uneven shape on the surface of the resin layer 3 is not limited to embossing, and other methods may be used, and so-called matte processing may also be performed using a method similar to embossing. For example, as shown in FIG. 7, a dimple-shaped (hemispherical) unevenness pattern is formed on the release sheet 4 to a depth of about 1 micron, and the uncured resin layer 3′ is applied thereon. Thereafter, the resin in the uncured resin layer 3′ is cured, and a polymer cement cured layer 2 is formed thereon, and then the release sheet 4 is peeled off, thereby obtaining a structure protection sheet having a matte design formed on the surface of the resin layer 3.

[0066] The method for printing the surface of the resin layer 3 is not particularly limited, and for example, printing may be performed using ink containing a solvent, a binder resin (urethane-based, acrylic-based, nitrocellulose-based, rubber-based, etc.), various pigments, extender pigments, and additives (plasticizers, drying agents, stabilizers, etc.). The pattern to be printed is not particularly limited, and letters, pictures, etc. may be selected as appropriate depending on the design to be imparted to the structure. Examples of the printing method for the ink include known printing methods such as offset printing, gravure printing, flexographic printing, silk screen printing, and inkjet printing. In order to improve adhesion to the resin layer 3, the surface of the resin layer 3 may be subjected to a treatment such as a corona treatment or an ozone treatment before printing the ink. As an example, the structure protection sheet of the present invention can be formed by providing an embossed or matte textured surface on the surface of a release sheet, forming a design on the textured surface by printing, and then providing a resin layer and a polymer cement layer in that order. It is also preferable to interpose a transparent resin layer such as an acrylic silicone at the interface between the release sheet and the uneven surface. In this case, the presence of a resin layer such as acrylic silicone on the outermost surface after the structure has been protected contributes greatly to improving weather resistance.

[0067] The design may be imparted to at least one surface of the resin layer 3. For example, if the design is imparted to the surface of the resin layer 3 opposite to the polymer cement hardened layer 2 side (the surface that becomes the surface of the structure protection sheet 1 or the surface of the resin layer 3 that comes into contact with the release sheet 4), a more favorable design can be imparted, and particularly when an uneven shape is imparted by embossing or the like, a design with excellent three-dimensional effect can be imparted. Furthermore, when a design is imparted to the surface of resin layer 3 facing hardened polymer cement layer 2, the imparted design is not directly exposed to the outside air, so that the excellent design can be maintained for a long period of time, and when embossing is performed, a three-dimensional design can be imparted while the surface of resin layer 3 can be made flat. In this case, resin layer 3 may be formed to be transparent or translucent. Furthermore, the structure protection sheet 1 according to the present invention may also suitably have a structure in which a printed layer is provided on the surface of the resin layer 3 facing the hardened polymer cement layer 2, and an uneven pattern is provided by embossing or the like on the surface opposite the resin layer 3. This makes it possible to simultaneously obtain excellent design properties from the printed layer and a three-dimensional effect from the uneven pattern of the embossing, and furthermore, the uneven pattern can also impart functions such as anti-glare properties, soundproofing, and anti-fouling properties.

[0068] The produced structure protection sheet 1 may be provided with a release sheet 4 on the surface of the resin layer 3 opposite the polymer cement cured layer 2, as shown in Figure 1. The release sheet 4 can protect the surface of the structure protection sheet 1 when it is delivered to the construction site, for example. At the construction site, the structure protection sheet 1 with the release sheet 4 still attached can be adhered to the target structure 21 (or via the primer layer 22 or adhesive layer 23), and then the release sheet 4 can be peeled off, greatly improving workability at the construction site. Note that the release sheet 4 is preferably a process paper used in the production process of the structure protection sheet 1.

[0069] The casting paper used as the release sheet 4 is not particularly limited in terms of material, etc., as long as it is a conventionally known casting paper used in the manufacturing process. For example, similar to known casting papers, preferred examples include laminated paper having an olefin resin layer such as polypropylene or polyethylene, or a layer containing silicone. The thickness is also not particularly limited, but can be any thickness, for example, about 50 to 500 μm, as long as it is not a thickness that hinders handling during manufacturing and construction.

[0070] (adhesive layer) In structure protection sheet 1 according to the present invention, adhesive layer 5 is provided on the surface of cured polymer cement layer 2 opposite to resin layer 3 (surface on the structure 21 side). The provision of adhesive layer 5 on the surface of hardened polymer cement layer 2 eliminates the need to apply an adhesive to form an adhesive layer at the work site when attaching structure protection sheet 1 of the present invention to structure 21, resulting in extremely excellent work efficiency, and structure protection sheet 1 of the present invention can be attached to structure 21 via an adhesive layer of uniform thickness without the need for a skilled craftsman. Furthermore, the provision of adhesive layer 5 makes it possible to improve the adhesion of structure protection sheet 1 of the present invention even if there are minute depressions or the like on the surface of structure 21 by filling the depressions with the pressure-sensitive adhesive layer.

[0071] The adhesive layer 5 may be an adhesive layer made using a pressure sensitive adhesive or an adhesive, but is preferably an adhesive layer in consideration of the pot life of the adhesive layer 5. The adhesive is not particularly limited and includes, for example, known adhesives such as acrylic adhesives, silicone adhesives, urethane adhesives, and rubber adhesives, but in the present invention, the adhesive layer 5 is preferably composed of an acrylic adhesive. Acrylic adhesives allow for easy adjustment of the adhesive strength to the structure 21, allowing for a high degree of freedom in material design, and also have excellent transparency, weather resistance, and heat resistance, allowing the structure 21 to be more suitably protected by the structure protection sheet 1 according to the present invention. The acrylic adhesive is not particularly limited, and commercially available products can be used, such as Olivine (registered trademark) 6574 (manufactured by Toyochem Co., Ltd.).

[0072] The amount of the adhesive layer 5 (hereinafter also referred to as adhesive layer) made of the acrylic adhesive is set to 20 g / m because it can exert sufficient adhesive strength to the surface of the structure 21 such as concrete. 2 More than 250g / m 2 The following is preferred: Furthermore, it is preferable that the adhesive strength when attached to the surface of the structure 21 via the adhesive layer is 0.5 N / mm2 or more. 2 If it is less than this, the adhesion of the structure protection sheet 1 according to the present invention to the surface of the structure 21 may be insufficient.

[0073] When the adhesive layer 5 in the structure protection sheet 1 according to the present invention is an adhesive layer composed of an adhesive, the adhesive is not particularly limited, and examples include known adhesives such as ultraviolet-curing adhesives and thermosetting adhesives. Examples of such adhesives include urethane adhesives, epoxy adhesives, adhesives using acrylic resins that exhibit rubber properties (e.g., synthetic rubbers containing acrylic esters as their main component), etc. Among these, adhesives made of the same type of resin component as that constituting the polymer cement cured layer 2 of the structure protection sheet 1 are more preferred because they increase the adhesive strength with the polymer cement cured layer 2.

[0074] In the structure protection sheet 1 according to the present invention, the adhesive layer 5 preferably contains a curing agent. By containing the curing agent, the adhesive layer 5 has better adhesion to the structure 21, and also has excellent punch-out strength for the structure protection sheet 1 according to the present invention. The structure protection sheet 1 according to the present invention preferably has a punching strength of 1.5 kN or more in the punching test specified in JSCE-K-533. By having the punching strength of 1.5 kN or more, the structure protection sheet 1 according to the present invention can effectively prevent problems such as the peeling of concrete or the like from the surface of a structure.

[0075] The curing agent is not particularly limited, and known curing agents such as isocyanate-based curing agents, amine-based curing agents, epoxy-based curing agents, and metal chelate-based curing agents can be used.

[0076] In the structure protection sheet 1 of the present invention, the adhesive layer 5 preferably has a gel fraction of 30% to 70%, with a more preferred lower limit of 40% and a more preferred upper limit of 65%, in order to provide excellent adhesion to the structure 21 and excellent punch-out strength for the structure protection sheet 1 of the present invention.

[0077] In the structure protection sheet 1 according to the present invention, the thickness of the adhesive layer 5 is preferably 20 to 500 μm. If it is less than 20 μm, the adhesive strength of the structure protection sheet 1 according to the present invention to the structure 21 may be insufficient, and if it exceeds 500 μm, the thickness is likely to vary, and when smoothed with a roller or the like to obtain a smooth application surface during application, excess adhesive may protrude from the edges. The lower limit of the thickness of the adhesive layer 5 is more preferably 90 μm, and the upper limit is more preferably 200 μm.

[0078] 1, in the structure protection sheet 1 according to the present invention, a release film 6 is preferably attached to the surface of the adhesive layer 5 opposite the cured polymer cement layer 2 in order to protect the surface of the adhesive layer 5. The release film 6 is not particularly limited, and examples thereof include a film having a base layer and a release layer. Examples of materials constituting the substrate layer include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene, and polymethylpentene, polyamides such as nylon 6, vinyl resins such as polyvinyl chloride, acrylic resins such as polymethyl methacrylate, cellulose resins such as cellulose acetate, and synthetic resins such as polycarbonate. The substrate layer may also be formed primarily from paper. Furthermore, the substrate layer may be a laminate of two or more layers.

[0079] Examples of materials constituting the release layer include silicone resins, melamine resins, and fluorinated polymers. The release layer can be formed by a coating method in which a coating liquid containing the material constituting the release layer and an organic solvent is applied to the substrate layer by a known method such as gravure coating, roll coating, comma coating, or lip coating, and then dried and cured. In addition, when forming the release layer, the lamination surface of the substrate layer may be subjected to corona treatment or easy-adhesion treatment.

[0080] The structure protection sheet 1 described above can expel moisture from structures such as concrete, thereby protecting the concrete structure 21 for a long period of time. In particular, the structure protection sheet 1 can be given performance suited to the characteristics of the concrete structure 21, allowing it to adapt to cracks and expansion that occur in the concrete structure 21, preventing the penetration of deterioration factors such as water and chloride ions into the concrete structure 21, and providing permeability that allows deterioration factors in the concrete structure 21 to be expelled. Furthermore, because such structure protection sheets 1 can be manufactured in factories, they can be mass-produced as high-quality sheets with stable properties. As a result, construction can be carried out without relying on the skills of a craftsman, shortening construction time and reducing labor costs.

[0081] The structural protection sheet of the present invention can be used for a variety of purposes in addition to surface reinforcement of civil engineering structures such as road bridges, tunnels, sluice gates and other river management facilities, sewerage pipes, port quays, bridges, and railings, and can provide a variety of effects. Specific examples include application to metal roofs such as galvanized iron roofs to impart metal corrosion protection, application to architectural piping etc. to reinforce the surface, application to ALC panels in factory buildings etc. to reduce deterioration or repair, application to the side walls of highways to impart contamination resistance and prevent reflection and add information due to the surface shape, application to sewer pipes (inner surface, outer surface, joints) to impart sulfuric acid resistance, application to sewage facilities (sewage treatment facilities, irrigation channels) to impart sulfuric acid resistance, application to indoor and outdoor floors and concrete rooftops to improve strength, application to underwater facilities to improve durability, application to wiring tunnels in areas close to the sea to reinforce the surface, application to dam spillways to prevent deterioration or repair deteriorated parts, application to civil engineering structures such as the inner walls of manholes, concrete roofs, concrete rooftops, indoor flooring made of stone or resin, buildings such as the inner and outer surfaces of chimneys, application to residential building materials to impart moss and mold resistance, application to the inner and outer surfaces of chimneys to reinforce the surface, application to the inner walls of manholes to prevent deterioration or repair, etc. Furthermore, the structure protection sheet according to the present invention can be modified by adding polyrotaxane, or the surface strength can be improved by adding a resin composition or particles.

[0082] [Method for manufacturing a structure using a structure protection sheet] As shown in Figure 2, the method for manufacturing a reinforced structure using the structure protection sheet according to the present invention is an application method using the structure protection sheet 1 according to the present invention, characterized in that the structure protection sheet 1 is attached to the surface of a structure 21 via an adhesive layer 5. When a release film 6 is attached to the surface of the adhesive layer 5, the release film 6 is peeled off to expose the adhesive layer 5 as shown in Figure 2(A), and then the structure protection sheet 1 is attached to the structure 21 from the adhesive layer 5 side as shown in Figure 2(B). This construction method makes it possible to easily apply the structure protection sheet 1 to the surface of the structure 21. As a result, even an unskilled worker can apply the structure protection sheet 1, which is made up of layers with little variation in thickness, to the structure 21, significantly reducing the construction period and protecting the structure 21 for a long period of time.

[0083] FIG. 5 is an explanatory diagram showing an example of application of the structure protection sheet 1 to a cast-in-place construction method. The cast-in-place construction method is a construction method in which a formwork 24 is formed at the work site, a concrete composition 21' is poured into the formwork 24, and the concrete composition 21 is left to harden, thereby obtaining a concrete structure 21. In this cast-in-place construction method, after the hardened concrete structure 21 is formed, the structure protection sheet 1 is attached to its surface, making the structure 21 less susceptible to deterioration. After the structure protection sheet 1 is attached to the structure 21, it is usually left to dry and harden the adhesive layer 5, and the structure protection sheet 1 is then attached.

[0084] On the other hand, for structures 21 that have already developed cracks, the damaged portions are repaired and then the structure protection sheet 1 is attached using the same application method as above. In this way, the lifespan of the concrete structure 21 can be extended.

[0085] A primer layer containing a curable resin material may be formed on the surface of the structure 21. The curable resin material is not particularly limited as long as it has the property of being cured into a resin by heat curing, photocuring, or other methods, but preferably includes an epoxy compound. In this case, the cured primer layer formed by curing the primer layer becomes an epoxy cured product. An epoxy cured product is generally obtained by curing an epoxy compound having two or more epoxy groups with a curing agent. The following describes an example in which an epoxy cured product is used as a primer layer.

[0086] Examples of the epoxy compound include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, orthocresol novolac type epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, diglycidyl ethers of phenols, and diglycidyl ethers of alcohols. Examples of curing agents include polyfunctional phenols, amines, polyamines, mercaptans, imidazoles, acid anhydrides, and phosphorus-containing compounds. Among these, examples of polyfunctional phenols include monocyclic bifunctional phenols such as hydroquinone, resorcinol, and catechol, and polycyclic bifunctional phenols such as bisphenol A, bisphenol F, naphthalenediols, and biphenols, as well as their halides and alkyl group-substituted derivatives. Furthermore, novolaks and resols, which are polycondensates of these phenols and aldehydes, can be used. Examples of amines include aliphatic or aromatic primary amines, secondary amines, tertiary amines, quaternary ammonium salts, and aliphatic cyclic amines, guanidines, and urea derivatives. Among the above examples, examples of materials for the primer layer (including curable resin materials) include epoxy resin primers that use, for example, a bisphenol A epoxy or bisphenol F epoxy base agent and a polyamine or mercaptan curing agent. The epoxy resin primers may also contain, in addition to the base agent and curing agent, coupling agents, viscosity modifiers, and curing accelerators. For example, Toagosei's two-component reactive curing waterborne epoxy resin emulsion "Aronble Coat P-300" (product name; "Aronble Coat" is a registered trademark of Toagosei) can be used as such a primer layer.

[0087] The primer layer is generally used as a primer for the structure 21. For example, the primer may be a solvent-type epoxy resin solution, or an epoxy resin emulsion or other general emulsion, or an adhesive, etc., applied to the surface of the structure 21. In this case, the primer can be applied by a conventional method, for example, by applying it to the surface of the structure 21 to be prevented from deterioration with a brush or roller, or by applying it by a conventional method such as spraying it with a spray gun, etc., to form a coating film. The thickness of the primer layer is not particularly limited, but is preferably within the range of 50 μm or more and 300 μm or less in a wet state. A thickness of 50 μm or more facilitates achieving a uniform thickness of the primer layer, taking into consideration the penetration of the primer layer material into the structure 21, such as concrete, and also facilitates ensuring adhesion between the structure and the structure protection sheet 1. The upper limit of the primer layer thickness is not particularly limited, but is preferably 300 μm or less for ease of application, minimizing misalignment of the two layers during adhesion, and optimizing the use of materials. The primer layer, which is provided as an undercoat layer for the structure 21, acts to enhance the mutual adhesion between the structure and the structure protection sheet 1. Therefore, if the primer layer has the above thickness, the structure protection sheet 1 can easily reinforce and protect the structure 21 stably for a long period of time. If cracks or defects have occurred in the structure 21, it is preferable to repair the cracks or defects before applying the primer layer. There are no particular restrictions on the repair method, but repairs are usually carried out using cement mortar, epoxy resin, or the like. [Example]

[0088] The present invention will be explained more specifically with reference to Examples, Comparative Examples and Reference Examples.

[0089] [Example 1] A 130 μm-thick release sheet 4 made of PP laminated paper was used. A resin layer-forming composition containing an acrylic resin was applied onto release sheet 4 and dried to form a single-layer resin layer 3 having a thickness of 100 μm. Thereafter, a polymer cement cured layer-forming composition was applied onto resin layer 3 and dried to form a single-layer polymer cement cured layer 2 having a thickness of 1.00 mm. An adhesive mixture with a gel fraction of 57% was prepared by mixing 100 parts by mass of an acrylic adhesive (Orivine (registered trademark) 6574 (manufactured by Toyochem Co., Ltd.)) with 6 parts by mass of an isocyanate curing agent (BHS8515 (manufactured by Toyochem Co., Ltd.)) on the surface of the polymer cement cured layer 2. This adhesive mixture was applied to the surface of the resin layer 3 and dried to form an adhesive layer 5 (adhesive layer) with a thickness of 200 μm. The resulting structure protection sheet 1 had a total thickness of 1300 μm. This structure protection sheet 1 was continuously produced in a factory controlled at about 25° C., and was wound into a roll including a release sheet.

[0090] The polymer cement cured layer-forming composition is an aqueous acrylic emulsion containing 45 parts by mass of a cement mixture. The cement mixture contains at least 70±5 parts by mass of Portland cement, 10±5 parts by mass of silicon dioxide, 2±1 parts by mass of aluminum oxide, and 1 to 2 parts by mass of titanium oxide. The acrylic emulsion contains at least 53±2 parts by mass of an acrylic acid polymer obtained by emulsion polymerization of an acrylic acid ester monomer using an emulsifier, and 43±2 parts by mass of water. The polymer cement cured layer-forming composition obtained by mixing these components and applying and drying the composition is a composite layer containing 50% by mass of Portland cement in an acrylic resin. Meanwhile, the resin layer-forming composition is an acrylic silicone resin. This acrylic silicone resin is an emulsion composition containing 60 parts by mass of an 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.

[0091] [Example 2] A structure protection sheet 1 was produced in the same manner as in Example 1, except that 100 parts by mass of an acrylic adhesive (Olivine (registered trademark) 6574 (manufactured by Toyochem Co., Ltd.)) was mixed with 3 parts by mass of an isocyanate curing agent (BHS8515 (manufactured by Toyochem Co., Ltd.)) to use an adhesive mixture with a gel fraction of 46%.

[0092] [Example 3] A 130-μm-thick release sheet 4 made of PP laminated paper was used. A resin layer-forming composition containing an acrylic resin was applied onto the release sheet 4 and dried to form a 100-μm-thick single-layer resin layer 3. Thereafter, a polymer cement cured layer-forming composition was applied onto the resin layer 3 and dried to form a 600-μm-thick single-layer polymer cement cured layer 2. Next, a 150-mesh vinylon mesh was laminated on the 600-μm-thick polymer cement cured layer 2, and the polymer cement cured layer-forming composition was applied onto the mesh and dried to form a 400-μm-thick single-layer polymer cement cured layer 2. Thereafter, a structure protection sheet 1 was produced in the same manner as in Example 1.

[0093] [Example 4] A 130-μm-thick release sheet 4 made of PP laminated paper was used. A resin layer-forming composition containing an acrylic resin was applied onto the release sheet 4 and dried to form a 100-μm-thick single-layer resin layer 3. Then, a polymer cement cured layer-forming composition was applied onto the resin layer 3 and dried to form a 300-μm-thick single-layer polymer cement cured layer 2. Next, a 510-mesh cheesecloth was layered on the 300-μm-thick polymer cement cured layer 2. Thereafter, a structure protection sheet 1 was produced in the same manner as in Example 1, except that the thickness of the adhesive layer 5 (sticky layer) was set to 100 μm.

[0094] [Comparative Example 1] A structure protection sheet was produced in the same manner as in Example 1, except that adhesive layer 5 was not provided.

[0095] [Reference example 1] A structure protection sheet was produced in the same manner as in Example 1, except that the amount of curing agent was adjusted so that the gel fraction of the adhesive layer 5 (sticky layer) was 30%.

[0096] [Reference example 2] A structure protection sheet was produced in the same manner as in Example 1, except that the amount of curing agent was adjusted so that the gel fraction of the adhesive layer 5 (sticky layer) was 70%.

[0097] [Reference example 3] A structure protection sheet was produced in the same manner as in Example 1, except that the thickness of adhesive layer 5 was 100 μm.

[0098] [Reference example 4] A structure protection sheet was produced in the same manner as in Example 1, except that the thickness of adhesive layer 5 was set to 50 μm.

[0099] [Reference example 5] An adhesive mixture with a gel fraction of 57% was prepared by mixing 100 parts by mass of an acrylic adhesive (AST-8752 (manufactured by Nippon Shokubai Co., Ltd.)) with 6 parts by mass of an isocyanate curing agent (Coronate L (manufactured by Tosoh Corporation)). A structure protection sheet was produced in the same manner as in Example 1, except that this adhesive mixture was used.

[0100] [Reference example 6] A structure protection sheet was produced in the same manner as in Example 1, except that a butyl rubber-based adhesive (Super Butyl Double-Sided Tape 5938 (manufactured by Sliontec Co., Ltd.)) was used.

[0101] [Reference example 7] A structure protection sheet was produced in the same manner as in Example 4, except that the thickness of adhesive layer 5 (sticky layer) was set to 50 μm.

[0102] [Adhesion] The adhesive strength of the structure protection sheets according to Examples 1, 3 and 4, and Reference Examples 1 to 7 was measured in accordance with JIS-A6909. The structure protection sheet according to Comparative Example 1 did not have adhesive layer 5, so its adhesive strength could not be evaluated. -Preparation of specimen (1) The test plate used is a mortar plate (70 x 70 x 20 mm) specified in JIS-A6909. (2) The adhesive layer 5 side of the obtained structure protection sheet is stuck to a mortar board, and the release sheet 4 is peeled off. Testing Method Measurements are performed in accordance with JIS-A6909. in particular, (1) An upper tension jig is attached with an adhesive to the surface of the structure protection sheet on the resin layer 3 side, and left to stand for 24 hours. (2) After curing, make cuts on all four sides of a 40mm x 40mm square around the jig until it reaches the concrete base. (3) Using the lower tensile jig and the backing plate, attach the specimen to the testing machine, and apply a tensile force vertically to the specimen surface using the upper tensile jig and the lower tensile jig to determine the maximum tensile load T (N). The loading rate is 1500 n / min. (4) Adhesion strength (N / mm 2 ) = Maximum tensile load T(N) / 1600.

[0103] [Push-out strength] Measurements were carried out in accordance with JSCE-K-533. It should be noted that the structure protection sheet according to Comparative Example 1 was not provided with adhesive layer 5, and therefore its punching strength could not be evaluated. -Preparation of specimen (1) The test plate used is a U-shaped gutter with a top cover (400 x 600 x 60 mm) as specified in Appendix E of JIS-A5372. (2) Cover the surface of the test plate with a structural protection sheet over an area of ​​400 x 400 mm. (3) Drill a hole approximately 100 mm in diameter and 55±3.0 mm deep in the center of the test plate on the opposite side of the coating. ·Measurement method (1) Load the specimen with the drilled surface facing up. (2) Destroy the drilled area at 1 mm / min. (3) Then, a displacement is applied at a loading rate of 5 mm / min. (4) A load was applied up to 50 mm, and the maximum load was taken as the push-out strength.

[0104] [Workability] From the viewpoint of workability, those that have an adhesive application process were rated as × in workability, and those that do not have an adhesive application process were rated as 〇.

[0105] [Table 1]

[0106] The present disclosure (1) provides a structure protection sheet that is used by being attached to the surface of a structure, An adhesive layer, a polymer cement hardened layer, and a resin layer are provided in this order. The structure protection sheet is characterized by the above. The present disclosure (2) is the structure protection sheet according to the present disclosure (1), in which the adhesive layer is composed of an acrylic pressure-sensitive adhesive. The present disclosure (3) is the structure protection sheet according to the present disclosure (1) or (2), which has a punching strength of 1.5 kN or more in a punching test specified in JSCE-K-533. This disclosure (4) has an adhesive strength of 0.5 N / mm when attached to the surface of a structure via an adhesive layer. 2 The structure protection sheet according to the present disclosure (1) or (2) is as described above. The present disclosure (5) is the structure protection sheet according to the present disclosure (1), (2), (3), or (4), wherein the adhesive layer has a thickness of 20 to 500 μm. The present disclosure (6) is the structure protection sheet according to the present disclosure (1), (2), (3), (4), or (5), wherein the polymer cement cured 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. The present disclosure (7) is the structure protection sheet according to the present disclosure (1), (2), (3), (4), (5), or (6), further comprising a mesh layer. The present disclosure (8) is a method for manufacturing a reinforced structure using the structure protection sheet described in the present disclosure (1), (2), (3), (4), (5), (6), or (7), characterized in that the structure protection sheet is attached to the surface of the structure via the adhesive layer. [Explanation of symbols]

[0107] 1. Structure protection sheet 2. Polymer cement hardened layer 3 Resin layer 3' Uncured resin layer 4 Release sheet 5 Adhesive layer 6 Release film 7 mesh layers 10 Embossing roll 21 Structures (concrete) 21' Concrete composition (structure-forming composition) 22 Primer layer 23 Adhesive 24 Formwork 21 Structures (concrete) 21' Concrete composition (structure-forming composition) 22 Primer layer 23 Adhesive 24 Formwork

Claims

1. A structure protection sheet that is used by being attached to the surface of a structure, an adhesive layer, a hardened polymer cement layer, and a resin layer are provided in this order; It further has a mesh layer, The mesh layer is embedded inside the polymer cement layer. A structure protection sheet characterized by:

2. The structure protection sheet according to claim 1 , wherein the adhesive layer is made of an acrylic pressure-sensitive adhesive.

3. 3. The structure protection sheet according to claim 1, which has a punching strength of 1.5 kN or more in a punching test according to JSCE-K-533.

4. Adhesion strength when attached to the surface of a structure via an adhesive layer is 0.5 N / mm ２ The structure protection sheet according to claim 1 or 2.

5. 3. The structure protection sheet according to claim 1, wherein the adhesive layer has a thickness of 20 to 500 μm.

6. 3. The structure protection sheet according to claim 1, wherein the cured polymer cement layer is a layer containing a cement component and a resin, and the resin content is 10% by weight or more and 40% by weight or less.

7. 3. A method for manufacturing a reinforced structure using the structure protection sheet according to claim 1 or 2, characterized in that the structure protection sheet is attached to the surface of the structure via the adhesive layer.

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