Concrete separation preventing member and concrete separation preventing method using the same

Abstract

To provide a concrete exfoliation preventive member and a construction method using the concrete exfoliation preventive member superior in construction workability with a simple structure of the concrete exfoliation preventive member itself, and improving an exfoliation preventive function of a concrete piece.SOLUTION: The sheet-type mesh sheet 12 has a rectangular shape or a square shape for preventing the falling of a peeled piece of concrete W, and is arranged on one main surface of the mesh sheet 12 and at a position spaced from an outer peripheral end of the mesh sheet 12. The concrete peeling prevention member 10 and the concrete peeling prevention method using the same include a reinforcement / protection layer 14 formed in a rectangular shape or a square shape, and the reinforcement / protection layer 14 imparts a shape holding function and a reinforcement / protection function to a deteriorated part 26 such as peeling, floating, and cracking of the concrete W and a portion of a mesh sheet 12 covering a place where the deteriorated part 26 may occur.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a concrete spalling prevention member and a construction method using the same, and more particularly to a concrete spalling prevention member for preventing concrete pieces from peeling off from concrete structures such as concrete tunnels, elevated roadways, bridges, and buildings, and a concrete spalling prevention method using the same. [Background technology]

[0002] In recent years, the deterioration of concrete, or the deterioration of concrete structures themselves, has become a major issue. This is due to factors such as the increase in vehicle traffic, increased loads, and higher speeds, which places excessive strain on structures, causing the surface of concrete structures to peel off, and the weakening of the surface layer due to substances harmful to concrete, such as acid rain and factory chemicals. Furthermore, reinforced concrete structures on or near the coast are subject to salt damage from sea salt particles, and the infiltration of salt into reinforced concrete structures that come into contact with seawater causes corrosion and expansion of the reinforcing bars, resulting in deterioration of these structures. Therefore, various methods for preventing the spalling of deteriorated concrete, methods for repairing spalled areas, and materials for use in these methods have been investigated and developed.

[0003] As a prior art of the present invention, for example, a repair or reinforcing sheet is proposed in which a laminate is formed having a protective layer that will become a surface layer and an adhesive layer for a concrete structure, and a reinforcing layer made of a fiber base material is interposed between these layers. The fiber base material is a sheet-like material made of organic fiber or inorganic fiber processed into a nonwoven or woven fabric, which is said to facilitate construction and stabilize quality (see, for example, Patent Document 1). In this prior art, a concrete structure repair / reinforcement sheet is formed by dry-laminating a protective layer formed by applying and drying a urethane-based two-component curing adhesive to a polyvinyl fluoride film, a reinforcing layer made of vinylon triaxial mesh, and an attachment layer made of a spunbond nonwoven fabric made of polyester fiber. This repair / reinforcement work involves first laitance-treating and correcting unevenness on the surface of the concrete structure using a disc sander or similar tool, then applying a primer and drying it. An epoxy resin adhesive is then applied to the surface as a construction adhesive. The aforementioned concrete structure repair / reinforcement sheet is then attached to the surface via its attachment layer. Once the construction adhesive has impregnated the attachment layer and hardened, the concrete structure repair / reinforcement sheet is adhered to the surface of the concrete structure. In this conventional technology, in a method for repairing and reinforcing concrete structures, instead of repeatedly applying woven or knitted fabric, adhesives or paints as a surface coating for the concrete structure and then carrying out a secondary finish, an outer layer material that serves as a protective layer with weather resistance, stain resistance and waterproofing properties, and an inner layer material that serves as an adhesive layer to facilitate adhesion to the concrete surface, are laminated in advance to form a laminate, and this laminate is then attached on site, which is said to reduce and shorten the repair and reinforcement work required to prevent concrete spalling.

[0004] As yet another prior art technique in addition to the present invention, it has been proposed to apply a mesh fabric for preventing concrete spalling to concrete structures, which is made by coating or impregnating a mesh fabric having 2 to 20 mm mesh openings with 2 to 4 axes formed from ply yarns of synthetic fibers, glass fibers, or carbon fibers with a total thread weight per axis of 300 to 10,000 decitex, with an ethylene-vinyl acetate copolymer emulsion or an acrylic resin emulsion, and further applying an acrylic or rubber-based adhesive to one side to form an adhesive layer (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-256707 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-16703 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the prior art described in Patent Document 1 requires many steps, including surface scraping, primer treatment, unevenness correction, and impregnation and bonding of reinforcing fiber sheets, resulting in problems such as high construction costs. Furthermore, there is a demand for even simpler repair and reinforcement sheets. Furthermore, this prior art cannot be applied to areas with large steps, such as tunnel joints and seams. In other words, when the repair and reinforcement sheet is applied to the surface of a concrete structure, wrinkles occur at the steps, hindering workability and ultimately workability.

[0007] Furthermore, in the prior art disclosed in Patent Document 2, after applying an adhesive to one side of a reinforcing fiber layer to the surface of a concrete structure, it is necessary to further apply a surface treatment agent to the other side of the reinforcing fiber layer, which also poses the problem of increasing the number of steps. On the other hand, because the spalling of concrete pieces from concrete structures such as bridges, tunnels, and elevated roads can lead to accidents, there is a demand for further improvements in the ability to prevent concrete pieces from spalling.

[0008] Therefore, the main object of the present invention is to provide a concrete spalling prevention member and a method for preventing concrete spalling using the same, which has a simple structure, excellent construction workability, and improved function of preventing concrete pieces from spalling. [Means for solving the problem]

[0009] The present invention of claim 1 is a concrete spalling prevention member comprising: a rectangular or square mesh sheet that prevents the peeling of spalled concrete pieces; and a rectangular or square reinforcing and protective layer that is disposed on one main surface of the mesh sheet at a distance from the outer edge of the mesh sheet, wherein the reinforcing and protective layer is endowed with shape retention functions as well as reinforcing and protective functions in the areas of the mesh sheet that cover deteriorated areas of concrete such as peeling, lifting, and cracks, and areas where such deteriorated areas are likely to occur. The present invention of claim 2 is an invention dependent on the invention of claim 1, and is a concrete spalling prevention member characterized in that the portion between the outer peripheral edge of the mesh sheet and the outer peripheral edge of the reinforcing / protective layer can be configured as four rectangular cut margins for forming butt joints when connecting multiple mesh sheets side by side. The present invention according to claim 3 is an invention dependent on the invention according to claim 2, and is a concrete spallation prevention member characterized in that the reinforcing and protective layer is formed from a special modified polyurea resin. The present invention of claim 4 is an invention dependent on the invention of claim 3, and is a concrete spalling prevention member characterized in that the reinforcing / protective layer includes a plurality of slits arranged at intervals on at least one of the four sides of the reinforcing / protective layer, and the plurality of slits are formed extending perpendicularly from the edge of at least one side for a predetermined length. The present invention of claim 5 is an invention dependent on the invention of claim 4, and is a concrete spalling prevention member characterized in that multiple slit portions are arranged on the side of the reinforcing / protective layer that is to be cut to form the butt joint. The present invention of claim 6 is a method for preventing concrete peeling, characterized in that the concrete peeling prevention member described in any one of claims 1 to 5 is used to cover and fix deteriorated parts of a concrete structure and parts where such deteriorated parts are likely to occur. The present invention of claim 7 is a concrete spalling prevention method that uses a concrete spalling prevention member according to any one of claims 1 to 5 to be applied to deteriorated parts of a concrete structure and areas where such deteriorated parts are likely to occur, and includes a primer layer formation step of forming a primer layer on the deteriorated parts and areas where such deteriorated parts are likely to occur, an adhesive priming step of forming an adhesive layer on top of the primer layer, and a mesh sheet affixing step of affixing the surface of the mesh sheet opposite to the surface on which the reinforcing / protective layer is disposed to the adhesive layer, wherein in the mesh sheet affixing step, the mesh sheet is affixed so that the reinforcing / protective layer covers the deteriorated parts of the concrete structure and areas where such deteriorated parts are likely to occur. The present invention of claim 8 is a method for preventing concrete spalling, which involves covering and fixing a concrete spalling prevention member according to any one of claims 2 to 5 to deteriorated portions of a concrete structure and areas where such deteriorated portions are likely to occur, and is characterized in that when arranging and connecting multiple mesh sheets in accordance with the range of the deteriorated portions and areas where such deteriorated portions are likely to occur, the method includes a butt joint forming step of cutting at least one cut margin out of the four sides of at least one mesh sheet to form at least one butt joint, and a connecting step of butting and connecting at least one butt joint to at least one edge out of the four sides of the reinforcing / protective layer of at least one other mesh sheet. [Effects of the Invention]

[0010] According to the concrete spalling prevention member of the present invention and the concrete spalling prevention method using the same, a concrete spalling prevention member having a simple structure and excellent workability can be obtained, and by using the spalling prevention member, the effect of preventing concrete pieces from spalling can be improved.

[0011] The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1(a) is a plan view showing an example of an embodiment of a concrete spalling prevention member according to the present invention, and FIG. 1(b) is a cross-sectional view taken along line AA in FIG. 1(a). [Figure 2] 1(a) and 1(b).

[0023] FIG. [Figure 3] 1(a) and 1(b) are explanatory diagrams showing an example in which the concrete spalling prevention member shown in FIG. 1(a) and 1(b) is applied to the repaired portion after repair work has been performed on the deteriorated portion of a concrete structure. [Figure 4] FIG. 2 is a cross-sectional view of a main part showing an example of the concrete spalling prevention member shown in FIGS. 1(a) and 1(b) applied to a location where deterioration may occur. [Figure 5] Figures 5(a) and (b) are plan views showing an example of a method for connecting multiple concrete separation prevention members according to the present invention side by side, where Figure 5(a) is a plan view showing an example of a butt joint forming process in which at least one cutting margin of one concrete separation prevention member is cut to form at least one butt joint, Figure 5(b) is a plan view showing an example of a connecting process in which at least one butt joint of one concrete separation prevention member is butted against at least one side of the reinforcing / protective layer of the other concrete separation prevention member, and Figure 5(c) is a cross-sectional view showing an example of a state in which one concrete separation prevention member and the other concrete separation prevention member have been installed on a concrete surface. [Figure 6]6(a) is a plan view showing another example of a method for connecting multiple concrete separation prevention members according to the present invention side by side, in which (a) of FIG. 6 is a plan view showing an example of a butt joint forming process in which four cutting margins of one concrete separation prevention member are cut to form a butt joint, and (b) of FIG. 6 is a plan view showing an example of a connecting process in which the butt joint of one concrete separation prevention member is butted against one side of the reinforcing / protective layer of the other concrete separation prevention member. [Figure 7] 1 is an exploded plan view showing an example of a method for connecting multiple concrete spalling prevention members according to the present invention vertically and horizontally. [Figure 8] This is a plan view showing the state in which multiple concrete separation prevention members of the present invention are connected vertically and horizontally, and is a plan view showing an example of a connection process in which the butt joints of multiple concrete separation prevention members are butted against one side of the reinforcing / protective layer of multiple concrete separation prevention members and connected. [Figure 9] Figure 9(a) is a plan view showing another example of an embodiment of the concrete spalling prevention member of the present invention, Figure 9(b) is an exploded oblique view for explaining an example of the concrete spalling prevention member shown in Figure 9(a) being installed on the surface of a concrete structure, and Figure 9(c) is a side view of the main parts of Figure 9(b). [Figure 10] FIG. 1 is an oblique view showing an example of a concrete structure to which the concrete spalling prevention member of the present invention is applied, and shows examples of deteriorated areas such as peeling, lifting, and cracks that form on the surface of the concrete structure, as well as areas such as steps, joints, and seams where such deteriorated areas may occur. [Figure 11] 10, is an explanatory diagram showing an example of opening of a construction joint due to shrinkage of concrete, and is an explanatory diagram for explaining the occurrence of cracks due to the adhesive force of the construction joint. [Figure 12]In relation to Figure 10, this is an explanatory diagram showing an example of opening of a construction joint due to shrinkage of concrete, and is an explanatory diagram for explaining the occurrence of cracks when the construction joint has a trapezoidal shape. DETAILED DESCRIPTION OF THE INVENTION

[0013] The concrete spalling prevention member of the present invention is a concrete spalling prevention member that has a simple structure and is easy to install, and its main purpose of using the spalling prevention member to improve the function of preventing concrete pieces from spalling is achieved by comprising a rectangular or square single-leaf mesh sheet that prevents the spalling of spalled concrete pieces, and a rectangular or square reinforcing and protective layer that is arranged on one main surface of the mesh sheet at a distance from the outer edge of the mesh sheet, and the reinforcing and protective layer imparts shape retention functions as well as reinforcing and protective functions to the parts of the mesh sheet that cover deteriorated areas of concrete such as spalling, lifting and cracking, and areas where such deteriorated areas are likely to occur. In addition, the concrete peeling prevention method of the present invention achieves the above-mentioned object by comprising a primer layer formation step of forming a primer layer on deteriorated areas and areas where deterioration may occur, an adhesive priming step of forming an adhesive layer on top of the primer layer, and a mesh sheet attachment step of attaching the surface of the mesh sheet opposite to the surface on which the reinforcing / protective layer is disposed to the adhesive layer, in which the mesh sheet is attached in the mesh sheet attachment step so that the reinforcing / protective layer covers the deteriorated areas of the concrete structure and areas where deterioration may occur. [Example]

[0014] FIG. 1(a) is a plan view showing an example of an embodiment of a concrete spalling prevention member according to the present invention, and FIG. 1(b) is a cross-sectional view taken along line AA in FIG. 1(a). The concrete spalling prevention member 10 according to Example 1 includes a mesh sheet 12, e.g., a horizontally elongated rectangular sheet. The mesh sheet 12 is intended to prevent concrete from spalling and falling off. The mesh sheet 12 is formed, for example, from durable vinylon filaments arranged in a triaxial configuration. As a result, the mesh sheet 12 has excellent alkali resistance and affinity with cement, and the vinylon fibers arranged in three directions provide excellent stress dispersion. The mesh sheet 12 is also weather-resistant against rust and corrosion, and is easy to apply to curved surfaces. The mesh sheet 12 is not limited to a horizontally elongated rectangular shape, and may be formed into a vertically elongated rectangular shape or a square shape.

[0015] A reinforcing / protective layer 14, e.g., a horizontally elongated rectangular shape, is disposed on one main surface of the mesh sheet 12. This reinforcing / protective layer 14 is disposed at a distance from the outer peripheral edge of the mesh sheet. The reinforcing / protective layer 14 is formed, for example, from a special modified polyurea resin, and is formed by laminating the special modified polyurea resin in the center of the mesh sheet 12. In this case, the special modified polyurea resin is formed by adding a modifier to the polyurea resin in order to broaden the temperature range in which it can be applied compared to ordinary polyurea resins. This special modified polyurea resin has a longer usable life (the time during which it can be used after mixing the base agent, curing agent, cure accelerator, etc.) than ordinary polyurea resins, and is superior in application properties such as resistance to soldering iron breakage. This reinforcing / protective layer 14 has both a reinforcing / protective function of reinforcing and protecting the mesh sheet 12 that covers deteriorated areas such as peeling, lifting, and cracks formed on the surface of a concrete structure and areas where such deteriorated areas are likely to occur, and a function of maintaining the shape of the covered areas of the mesh sheet 12. This reinforcing / protective layer 14 is not limited to a horizontally elongated rectangular shape, and may also be formed into a vertically elongated rectangular shape or a square shape. In the concrete separation prevention member 10 according to Example 1, a finishing layer 18 made by applying a finishing material may be formed on the upper surface of the reinforcing / protective layer 14 .

[0016] FIG. 3 is an explanatory diagram showing an example in which the concrete spalling prevention member shown in FIGS. 1(a) and 1(b) is applied to the repaired portion after repair work has been performed on the deteriorated portion of a concrete structure. As shown in FIG. 3, the concrete spalling prevention method using the concrete spalling prevention member 10 first performs a surface preparation on deteriorated areas 26, such as peeling, lifting, and cracks, formed on the surface of a concrete structure and areas where such deteriorated areas 26 are likely to occur, forming a surface preparation layer 24, for example, as shown in FIG. 3. The surface preparation includes sanding, etc., to polish and clean the concrete surface, remove the deteriorated areas, and then smooth the concrete surface. If the deteriorated areas 26 have cross-sectional defects or severe cracks, separate repair work such as cross-sectional repair and crack repair is performed to repair the area, and then a surface preparation layer 24 is formed on the surface of the concrete W including the repaired area (hereinafter referred to as the "repaired area") 28, for example, as shown in FIG. 4.

[0017] Next, after confirming that the base of the concrete surface is dry, a one-component epoxy resin or the like is uniformly applied with a roller or the like to form a primer layer 22 (primer layer forming step). In this case, the primer layer 22 formed has low viscosity, which provides excellent impregnation performance into the concrete surface. If the unevenness is large, after forming the primer layer 22, an unevenness correction step is carried out, for example, after an interval of about 4 to 5 hours, by applying a one-component epoxy resin or the like (primer coat) or smoothing the concrete surface with epoxy putty, etc. This unevenness correction step may be omitted depending on the condition of the base.

[0018] Furthermore, a predetermined amount of adhesive, such as a special modified polyurethane resin, is applied (primed) to the upper side of the smoothed concrete surface using, for example, rubber putty, to form adhesive layer 16 (adhesive priming process). In this case, a predetermined amount of adhesive is stored in advance in a storage bag (not shown), such as a pouch, that can be opened along the cutting line from the notch. If the required number of these storage bags are brought to the construction site, workers can easily open the storage bag and use the required amount of adhesive, without having to rely on the experience or skill of the worker. The adhesive layer 16 imparts flexibility to the cured coating, making it excellent at following up cracks and providing excellent push-out strength at temperatures from -30 to 50°C. This special modified polyurea resin has a fast surface curing speed, making it highly weather-resistant to rain and condensation after application.

[0019] Furthermore, after the adhesive priming step, the mesh sheet 12 of the concrete separation prevention member 10 is attached to the top surface of the adhesive layer 16 (mesh sheet attachment step). In this case, the mesh sheet 12 is attached to the deteriorated portion 26 of the concrete W and areas where the deteriorated portion 26 is likely to occur, so that the reinforcing / protective layer 14 is covered by the mesh sheet 12. This adhesive priming step applies an adhesive made of a special modified polyurethane resin to the deteriorated portion 26 and the surrounding concrete surface. In particular, when the adhesive is impregnated into the mesh sheet 12 and the adhesive and the reinforcing / protective layer 14 bond and harden through the mesh openings (openings / mesh) of the mesh sheet 12, the mesh sheet 12 and the adhesive layer 16 become integrated and are firmly adhered and fixed to the deteriorated portion 26 and the surrounding concrete surface. In this [Example 1], the reinforcing / protective layer 14 and the adhesive layer 16 are formed from the same adhesive, a special modified polyurea resin, and the amount of adhesive applied to the reinforcing / protective layer 14 is greater than the amount of adhesive applied to the adhesive layer 16, i.e., the film thickness of the reinforcing / protective layer 14 is greater than the film thickness of the adhesive layer 16.

[0020] Then, if necessary, a finishing material is applied to the top of the reinforcing / protective layer 14 to form the finishing layer 18 (finishing layer formation process). Examples of finishing materials that can be used include two-component paints based on acrylic urethane and polyurethane resins. These paints have excellent UV resistance, are room-temperature drying paints that offer good corrosion protection, and produce smooth, glossy coatings that are soft enough to conform to vibrations and fine cracks in the substrate. By the above-described concrete separation prevention method, the concrete separation prevention member 10 is fixed to cover the deteriorated portion 26 of the concrete structure and the portion where the deteriorated portion 26 may occur, as shown in FIG.

[0021] According to this concrete spalling prevention method, the concrete spalling prevention member 10 is formed in advance by laminating the reinforcing and protective layer 14 onto a single-piece mesh sheet 12, which eliminates the need for on-site topcoat application, shortening the construction period, and also allowing partial construction and even for small areas of deteriorated area 26. Furthermore, the adhesive priming process allows only the required amount of adhesive to be used, eliminating the need for advanced techniques and enabling construction at low cost.

[0022] Figure 5(a) is a plan view showing an example of a butt joint forming process in which one cutting margin of one concrete spalling prevention member is cut to form a butt joint, Figure 5(b) is a plan view showing an example of a connecting process in which the butt joint of one concrete spalling prevention member is butted against one side of the reinforcing / protective layer of the other concrete spalling prevention member and connected, and Figure 5(c) is a cross-sectional view showing an example of the state in which the butt joint of one concrete spalling prevention member is butted against one side of the reinforcing / protective layer of the other concrete spalling prevention member and connected, and installed on the concrete surface. In the concrete separation prevention method using the concrete separation prevention member 10, when a single concrete separation prevention member 10 cannot be applied to the deteriorated portion 26 of a concrete structure or the area that is likely to become the deteriorated portion 26, multiple concrete separation prevention members 10 are attached and fixed to the area as appropriate depending on the size of the area.

[0023] That is, when two or more concrete spalling prevention members 10 are prepared, one or more of the appropriate number of concrete spalling prevention members 10 include, for example, four rectangular cutting margins 30 in the portion between the outer periphery of the mesh sheet 12 and the outer periphery of the reinforcing / protective layer 14, as shown in Figure 5(a), for example. These cutting margins 30 can be formed between the mesh sheet 12 and the reinforcing / protective layer 14. In this case, one vertically elongated rectangular portion is provided between each of the two longitudinally opposing edges of the mesh sheet 12 and the two longitudinally opposing edges of the reinforcing / protective layer 14, and this rectangular portion can be configured as the cutting margin 30. In addition, one horizontally elongated rectangular portion is provided between each of the two widthwise opposing edges of the mesh sheet 12 and the two widthwise opposing edges of the reinforcing / protective layer 14, and this rectangular portion can be configured as the cutting margin 30. Furthermore, in this concrete spalling prevention member 10, when at least one of the four cutting margins 28 described above is cut, one butt joint 32 can be formed at the edge of at least one of the four sides of the mesh sheet 12.

[0024] Therefore, below, an example of a connection method for arranging and connecting multiple mesh sheets 12 depending on the range of the deteriorated portion 26 and the location where the deteriorated portion 26 may occur will be described with reference to Figures 5(a), (b) and (c). In this connection method, first, in at least one concrete spalling prevention member 10, the cut margin 28 of at least one of the four sides of the mesh sheet 12 is cut to form at least one butt joint 32 (butt joint forming step), as shown in Fig. 5(a). Then, in at least one other concrete spalling prevention member 10, the butt joint 32 is butted against at least one edge of the four sides of the reinforcing / protective layer 14 of the mesh sheet 12, as shown in Fig. 5(b) (connecting step). Then, as shown in Figure 5 (C), one mesh sheet 12 is attached via an adhesive layer 16 to cover the deteriorated areas 26 on the concrete surface W of the concrete structure and areas where the deteriorated areas 26 may occur, on the opposite side to the side on which the reinforcing / protective layer 14 of the mesh sheet 12 is disposed (mesh sheet attachment process). In this case, after the adhesive priming process, the mesh sheet 12 of at least one of the multiple concrete spalling prevention members 10 is attached to the deteriorated portion 26 and the area where the deteriorated portion 26 is likely to occur, and then, using the connection process method, the mesh sheet 12 of at least one of the concrete spalling prevention members 10 is attached laterally to the deteriorated portion 26 and the area where the deteriorated portion 26 is likely to occur so that they are lined up side by side. In addition, the mesh sheets 12 of a plurality of concrete spalling prevention members 10 may be connected side by side in advance and then attached to the deteriorated portions 26 and areas where the deteriorated portions 26 may occur.

[0025] In the connection methods shown in Figures 5(a), (b), and (c), the mesh sheet 12 of at least one concrete spalling prevention member 10 is connected horizontally in the longitudinal direction (left-right direction) of the mesh sheet 12 of at least one other concrete spalling prevention member 10, but it is also possible to connect the mesh sheet 12 of at least one other concrete spalling prevention member 10 horizontally in the width direction (left-right direction) of the mesh sheet 12 of at least one other concrete spalling prevention member 10, as shown in Figures 6(a) and 6(b), for example. 5(a), (b), and (c), one butt joint 32 formed by cutting, for example, one cutting margin 30 of one concrete spalling prevention member 10 is butted against the edge of one side of the reinforcing / protective layer 14 of the other concrete spalling prevention member 10. However, for example, as shown in FIG. 6(a), one butt joint 32 formed by cutting four cutting margins 30 of one concrete spalling prevention member 10 and one mesh sheet 12 as a joint formed by cutting three cutting margins 30 of the other concrete spalling prevention member 10 may be overlapped (see overlap portion OL) as shown in FIG. 6(C), and the butt joint 32 of one concrete spalling prevention member 10 may be butted against the edge of one side of the reinforcing / protective layer 14 of the other concrete spalling prevention member 10. In this case, the widthwise length of the overlap portion OL between one side of the reinforcing / protective layer 14 of one concrete spalling prevention member 10 and the mesh sheet 12 as one joint portion is preferably 100 mm to 150 mm, for example, and is preferably set to at least 100 mm.

[0026] Furthermore, in the connection methods shown in Figures 5(a), (b), and (c) and Figures 6(a) and (b), the mesh sheets 12 of multiple concrete spalling prevention members 10 are connected horizontally, but the mesh sheets 12 of multiple concrete spalling prevention members 10 may also be connected vertically and horizontally, as shown in Figures 7 and 8, for example. In any of the connection methods shown in Figures 5(a), (b), and (c), Figures 6(a) and (b), and Figures 7 and 8, one concrete separation prevention member 10 is first attached and fixed to a deteriorated portion 26 on the concrete surface W of a concrete structure and to a location where the deteriorated portion 26 is likely to occur, and then one of the other multiple concrete separation prevention members 10 is sequentially attached and fixed thereto. [Example]

[0027] Figure 9(a) is a plan view showing another example of an embodiment of the concrete spalling prevention member of the present invention, Figure 9(b) is an exploded oblique view for explaining an example of the concrete spalling prevention member shown in Figure 9(a) being installed on the surface of a concrete structure, and Figure 9(c) is a side view of the main parts of Figure 9(b). The concrete separation prevention member 10 according to Example 2 differs from the concrete separation prevention member 10 according to Example 1 in that the reinforcing / protective layer 14 has a plurality of slits 34 . 9(a), (b), and (c), the concrete spalling prevention member 10 includes a reinforcing / protective layer 14 that includes a plurality of slits 34 spaced apart along at least one of the four sides of the reinforcing / protective layer 14. The slits 34 extend perpendicularly from the edge of the at least one side a predetermined length. In this case, the slits 34 are arranged, for example, at equal intervals along the length of one side of the mesh sheet 12 that faces the width direction, and the slits 34 extend a predetermined length toward the other side of the mesh sheet 12 that faces the width direction. Furthermore, the plurality of slits 34 are arranged on the side of the reinforcing / protective layer 14 on the side of the cutting margin 30 for forming the butted portion 32. The plurality of slits 34 need only be formed at intervals on at least one of the four sides of the reinforcing / protective layer 14, and may be formed on two or three of the four sides, or may be formed on all four sides.

[0028] The concrete spalling prevention member 10 of [Example 2] has multiple slits 34 compared to the concrete spalling prevention member 10 of [Example 1], and therefore can be applied to large stepped areas, such as joints in tunnels and seams, as shown in Figures 10, 11, and 12. On the other hand, the concrete separation prevention member 10 according to [Example 1] does not have slits 34, and therefore when the concrete separation prevention member 10 is applied to cover and attach deteriorated areas such as peeling, lifting, and cracks in concrete that have occurred in such stepped areas, or to locations where such deteriorated areas occur (see, for example, Figures 10 and 11), wrinkles may occur in the stepped areas, which may impede workability and ultimately construction. In contrast, as shown in Figures 9(b) and 9(c), in the concrete separation prevention member 10 according to Example 2, even when the mesh sheet 12 of the concrete separation prevention member 10 is applied to the deteriorated portion and the location where the deteriorated portion occurs in the step portion 36, particularly across the corner of the step portion 36, it is possible to prevent wrinkles and distortion from occurring in the reinforcing / protective layer 14. In this case, when the reinforcing / protective layer 14 is curved to apply the reinforcing / protective layer 14 across the corner of the step portion 36, the reinforcing / protective layer 14 is curved, opening the open ends of the multiple slits 34, and the multiple slits 34 can disperse the stress concentration that causes wrinkles, distortion, and the like. This makes it possible to prevent wrinkles and distortions from occurring, and to prevent problems with workability and ultimately with workability.

[0029] In both [Example 1] and [Example 2] according to the present invention, As shown in Figures 1(a) and (b), a concrete spalling prevention member 10 is manufactured, having a rectangular or square mesh sheet 12 with a rectangular or square reinforcing / protective layer 14 disposed on one main surface thereof. At least one of the four cutting margins 30 is cut to form a butting portion 32 at the edge of at least one side of at least one reinforcing / protective layer 14, so that the edges of at least one side of at least one reinforcing / protective layer 14 of multiple concrete spalling prevention members 10 can be arranged to butt against each other as needed. Therefore, in the concrete separation prevention method using the concrete separation prevention member 10 of the present invention, when a single concrete separation prevention member 10 cannot be applied to the deteriorated portion 26 of a concrete structure or the area that is likely to become the deteriorated portion 26, it is possible to attach and fix multiple concrete separation prevention members 10 to the area as appropriate, depending on the size of the area.

[0030] Furthermore, the configuration of the concrete separation prevention member 10 according to the present invention allows for a shorter construction period, allows partial construction, and is applicable even when the deteriorated area 26 is small. Furthermore, the adhesive priming process allows for the use of only the required amount of adhesive, does not require advanced techniques, and can be applied at low cost. Therefore, the concrete separation prevention member 10 according to the present invention and the concrete separation prevention using it are excellent from the perspective of the SDGs. [Explanation of symbols]

[0031] 10. Concrete spalling prevention material 12 mesh sheets 14 Reinforcement and protection layer (top coat) 16 Adhesive layer (primer) 18 Finishing layer (finishing material) 20 Uneven adjustment layer 22 Primer layer 24 Undercoating layer 26 Deteriorated areas of concrete (peeling, cracks, lifting, etc.) 28 Restoration Department 30 Disconnect 32 Butt joint 34 Slit 36 Step W Concrete OL overlapping part

Claims

1. A rectangular or square mesh sheet that prevents concrete from peeling off. a reinforcing and protective layer formed in a rectangular or square shape and disposed on one main surface of the mesh sheet at a position spaced apart from the outer peripheral edge of the mesh sheet; A concrete spalling prevention member characterized in that the reinforcing / protective layer is provided with shape retention functions as well as reinforcing / protective functions in the mesh sheet areas that cover deteriorated areas of concrete such as peeling, lifting, and cracks, and areas where such deteriorated areas are likely to occur.

2. A concrete spalling prevention member as described in claim 1, characterized in that the portion between the outer peripheral edge of the mesh sheet and the outer peripheral edge of the reinforcing / protective layer can be configured as four rectangular cutting margins for forming butt joints when connecting multiple mesh sheets in a vertical or horizontal row.

3. 3. The concrete spalling prevention member according to claim 2, wherein the reinforcing and protective layer is formed of a special modified polyurea resin.

4. The concrete spalling prevention member described in claim 3, characterized in that the reinforcing / protective layer includes a plurality of slits arranged at intervals on at least one of the four sides of the reinforcing / protective layer, and the plurality of slits are formed extending perpendicularly from the edge of the at least one side for a predetermined length.

5. 5. The concrete spalling prevention member according to claim 4, wherein the plurality of slits are arranged on the side of the reinforcing / protective layer that is to be cut to form the butt joint.

6. A method for preventing concrete spalling, comprising covering and fixing the concrete spalling prevention member according to any one of claims 1 to 5 to a deteriorated portion of a concrete structure and a portion where the deteriorated portion is likely to occur.

7. A concrete spalling prevention method that uses the concrete spalling prevention member according to any one of claims 1 to 5 to be applied to a deteriorated part of a concrete structure and a part where the deteriorated part is likely to occur, a primer layer forming step of forming a primer layer on the deteriorated portion and on a portion where the deteriorated portion may occur; an adhesive priming step of forming an adhesive layer on the upper side of the primer layer; a mesh sheet attaching step of attaching a surface of the mesh sheet opposite to a surface on which the reinforcing / protective layer is disposed to the adhesive layer, A method for preventing concrete peeling, characterized in that in the mesh sheet attachment process, the mesh sheet is attached so that the reinforcing / protective layer covers deteriorated parts of the concrete structure and areas where such deteriorated parts are likely to occur.

8. A method for preventing concrete separation, comprising covering and fixing the concrete separation prevention member according to any one of claims 2 to 5 to a deteriorated portion of a concrete structure and a portion where the deteriorated portion is likely to occur, a butt joint forming step of cutting the cutting allowance of at least one of the four sides of at least one of the mesh sheets to form at least one butt joint when arranging and connecting the plurality of mesh sheets in accordance with the range of the deteriorated portion and the location where the deteriorated portion may occur; A method for preventing concrete spalling, characterized by including a connecting step of butting and connecting at least one of the butt joints to at least one edge of the four sides of the reinforcing / protective layer of at least one other of the mesh sheets.

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