Surface protection structure for concrete structure and method for constructing surface protection structure for concrete structure

Abstract

To prevent a concrete structure from being broken by a generated crack, and to prevent the generation of the crack in the concrete structure, in the concrete structure in which the crack is generated.SOLUTION: In the surface protective structure A of the concrete structure 1 in which a protective layer 2 is laminated on the surface of the concrete structure 1, the protective layer 2 is formed by embedding a net-like body 3 in a resin layer, and the elongation percentage of the resin layer is 200% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surface protection structure for a concrete structure and a construction method for the surface protection structure for a concrete structure. [Background technology]

[0002] Alkali-aggregate reaction (ASR) is one of the phenomena that deteriorate concrete structures. Alkali-aggregate reaction is a chemical reaction that occurs when water penetrates alkaline concrete, producing alkali ions that react with silica minerals contained in the aggregate, resulting in alkali-silica reaction (ASR). The alkali-aggregate reaction causes abnormal expansion around the aggregate, which leads to cracks in the concrete structure and leads to the destruction of the concrete structure, such as spalling. When cracks occur in concrete structures, one repair method is to inject and fill the cracks with resin such as epoxy resin, but it is difficult to completely fill the innermost part of the crack with resin, and this method does not prevent new cracks from occurring (Patent Documents 1 to 3).

[0003] Alkali-aggregate reaction does not occur with all aggregates, but is more likely to occur with aggregates that contain a large amount of reactive minerals such as silica minerals. To determine whether an alkali-aggregate reaction has occurred, it is necessary to actually check whether cracks have occurred and whether those cracks have been caused by an alkali-aggregate reaction. Concrete structures include all concrete structures in buildings, such as tunnels and viaducts. Factors that cause cracks to form on the surface of concrete structures include alkali-aggregate reaction, as well as abnormal expansion caused by rusting of reinforcing bars in the concrete structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-189954 [Patent Document 2] Japanese Patent Application Publication No. 2019-7217 [Patent Document 3] Patent No. 6458197 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, if a concrete structure in which cracks have occurred due to alkali-aggregate reaction or the like is left unattended, the concrete structure will be destroyed. Therefore, the object is to prevent cracks occurring in a concrete structure from leading to destruction of the concrete structure, and to prevent cracks from occurring in the concrete structure. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention has the following configuration. A surface protection structure for a concrete structure in which a protective layer is laminated on the surface of the concrete structure, the protective layer is formed by embedding a mesh body in a resin layer, The resin layer has an elongation rate of 200% or more. A surface protection structure for a concrete structure. The present invention also has the following configuration. A construction method for a surface protection structure of a concrete structure in which a protective layer is laminated on the surface of the concrete structure, comprising: The method for constructing a surface protection structure for a concrete structure includes a primer step of applying a resin agent to the surface of the concrete structure to form a primer layer, a coating step of applying a reticulate body to the surface of the primer layer, a topcoat step of applying the resin agent used in the primer step to the surface of the primer layer and covering the reticulate body, and a curing step of curing the applied resin agent, The resin layer formed by curing the resin agent has an elongation of 200% or more. A method for constructing a surface protection structure for a concrete structure, comprising: [Effects of the Invention]

[0007] The surface protection structure for a concrete structure and the method for constructing the surface protection structure for a concrete structure of the present invention can prevent cracks that occur in the concrete structure from leading to the destruction of the concrete structure, and can also prevent cracks from occurring in the concrete structure. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a surface protection structure for a concrete structure according to an embodiment of the present invention. [Figure 2] 1 is a surface view (view taken along arrow (2) in FIG. 1) showing a surface protection structure for a concrete structure according to an embodiment of the present invention. [Figure 3] FIG. 10 is a surface view showing a surface protection structure for a concrete structure according to a modified example of an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view showing a construction process of a surface protection structure for a concrete structure according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment] Hereinafter, a surface protection structure A for a concrete structure according to an embodiment of the present invention and a method for constructing the surface protection structure A for a concrete structure 1 will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts with the same functions, and duplicated descriptions in each drawing will be omitted as appropriate.

[0010] [Surface protection structure] The surface protection structure A has a protective layer 2 laminated on the surface 10 of the concrete structure 1, and the protective layer 2 comprises a resin layer and a mesh body 3 laminated so as to be embedded within the resin layer. As shown in Figure 2, from the outside of the surface protection structure A, the mesh body 3 in the resin layer can be seen, and the surface 10 and cracks 11 can be seen through the protective layer 2. It is preferable to apply the surface protection structure A to the entire surface 10 of the concrete structure 1 in which the cracks 11 have occurred. This is because, if the concrete structure 1 uses the same aggregate, there is a high possibility that cracks 11 will occur after application of the surface protection structure A even in areas where no cracks 11 have occurred when the surface protection structure A is applied. In consideration of the construction cost of the surface protection structure A, the surface protection structure A may be constructed only at the location where the crack 11 has occurred and in a predetermined area around it.

[0011] Furthermore, the surface protection structure A may be applied in advance to the surface 10 of the concrete structure 1 on which cracks 11 have not yet occurred. However, since the occurrence of cracks 11 is due to the aggregate used and does not necessarily occur, taking into account construction costs, it is preferable to apply surface protection structure A to the surface 10 of the concrete structure 1 where cracks 11 actually occur.

[0012] As described above, the protective layer 2 has a degree of translucency that allows the surface 10 and cracks 11 to be visually recognized. The term "translucent" as used herein means that the surface 10 and the like have a transmittance that allows the surface 10 to be seen from the outside of the surface protection structure A. As long as the surface has such a transmittance, it may be either colorless and transparent or colored and transparent. The translucency allows the state of the surface 10 and cracks 11 to be observed through the surface protection structure A after application.

[0013] The protective layer 2 is formed by applying a resin agent 2A to the surface 10 and curing it, and by curing it firmly adheres to the surface 10. In addition, a mesh body 3 is embedded within the protective layer 2. Alternatively, a primer for improving adhesion between the resin agent 2A forming the protective layer 2 and the surface 10 may be applied to the surface 10 to form a primer layer, and then the resin agent may be applied onto this primer layer.

[0014] The resin agent 2A used has an elongation percentage (elongation percentage at break) of 200% or more, preferably 240% or more, and more preferably 280% or more. By having an elongation rate equal to or greater than a predetermined level, the protective layer 2 can follow the movement of the surface 10 when cracks occur or grow larger, preventing the protective layer 2 from cracking and destroying the concrete structure, or preventing rainwater or the like from penetrating the surface 10 and penetrating into the interior of the concrete structure 1, causing new alkali-aggregate reactions, etc. As described above, the resin layer preferably has light-transmitting properties, and it is preferable to use a light-transmitting resin agent 2A.

[0015] Furthermore, if a waterproof and moisture-permeable resin agent 2A is used, the waterproof property can prevent rainwater and the like from penetrating the surface 10, and the moisture permeability can release moisture in the concrete structure 1 to the outside air from the surface 10. In other words, the moisture in the concrete structure 1 can be reduced, and the occurrence of alkali-aggregate reaction can be prevented. Furthermore, if a non-flammable or flame-retardant resin is used as the resin agent 2A, even if a fire breaks out due to a car accident in a tunnel, for example, the damage caused by the fire can be suppressed by the non-flammable or flame-retardant resin layer.

[0016] Examples of the resin agent 2A as described above include silicone-based resin agents such as one-component liquid rubber KE-441 (Shin-Etsu Chemical Co., Ltd.), one-component silicone-based sealant (Cemedine Co., Ltd.), Bond Modified Silicone Coke (Konishi Co., Ltd.), Joint Coke (registered trademark, Yayoi Chemical Industry Co., Ltd.), and Arc Seal S-100J (Tilement Co., Ltd.), but other resin agents may also be used as long as they have the properties as described above.

[0017] The mesh body 3 is formed by weaving weft threads 3A and warp threads 3B, which are made up of a large number of bundles of thin fibers. As shown in FIG. 1, the resin agent penetrates the mesh 3C formed between the weft threads 3A and warp threads 3B, and impregnates and hardens the weft threads 3A and warp threads 3B, thereby firmly holding the mesh body 3 within the protective layer 2. The mesh body 3 may be formed into a fixed shape with a certain size (area), or may be formed into a long shape in the warp or weft direction. The fibers constituting the weft threads 3A and warp threads 3B are preferably synthetic resin fibers (such as aramid fibers) with high tensile strength, metal fibers, glass fibers, carbon fibers, and the like.

[0018] The size (opening) of the mesh 3C is preferably large enough to allow visual confirmation of the state of the surface 10, etc., and to hold back the cracks 11 and the expansion of the surface 10 caused by the cracks 11. Specifically, to make the state of the surface 10 visible, the size of the mesh 3C is preferably about 10 mm or more on a side, and to hold back the surface 10, the size of the mesh 3C is preferably about 30 mm or less on a side. The mesh body 3 is not limited to a plain weave in which the weft threads 3A and warp threads 3B are woven and the mesh 3C is rectangular, but may also be any other shape, such as a hexagonal mesh 3C (tortoiseshell mesh) or a triangular mesh 3C.

[0019] According to such a surface protection structure A, the protective layer 2 having the reticulated body 3 embedded therein is laminated on the surface 10, thereby protecting the surface 10 of the concrete structure 1 in which a crack 11 has occurred, and the protective layer 2 can hold concrete pieces that are about to fall off. In addition, the condition of the surface 10, etc. can be visually confirmed through the protective layer 2. Furthermore, even if a fire breaks out due to a car accident inside the tunnel, the fire will not spread to the non-combustible or flame-retardant protective layer 2, thereby limiting the damage caused by the fire.

[0020] [Variations] Next, a surface protection structure A' according to a modified example of the embodiment of the present invention will be described with reference to Figure 3. In the surface protection structure A' according to this modified example, the mesh body 3 is not a woven fabric as in the example, but a molded product formed into a mesh shape using a molding die. Note that parts that overlap with the embodiment will be assigned the same reference numerals and will not be described again.

[0021] The mesh body 3 of the surface protection structure A' is a molded product made of a thin synthetic resin material or a thin metal plate with high tensile strength, molded so that the mesh 3C is rectangular. In the example shown in Figure 3, multiple such mesh bodies 3 are used, arranged so that the edges 3D of the meshes abut. It is also possible to use molded products made of metal fiber, glass fiber, carbon fiber, etc. Furthermore, the shape of the mesh may be hexagonal, triangular, or any other shape, as in the embodiment.

[0022] This surface protection structure A' also has the same effect as the surface protection structure A of the embodiment, and since the mesh body 3 is a molded product shaped like a mesh, it has the effect of being easy to handle during work and transportation.

[0023] [Construction method for surface protection structure] Next, a construction method for the surface protection structure A will be described with reference to Figures 4(a) to 4(c). This construction method is not limited to constructing the surface protection structure A, but can also be applied to constructing the surface protection structure A'.

[0024] Primer coating process (first process: Figure 4(a)): The resin agent 2A is applied to the surface 10 of the concrete structure 1 using a roller, brush, etc., or the resin agent 2A is sprayed onto the surface 10 using a spray nozzle, and then applied as a finishing touch using a roller, brush, etc. to form a primer layer 20A (resin layer). In this undercoating step, the resin agent 2A is applied so that the undercoated surface 20B becomes smooth, and the undercoat layer 20A (resin layer) can function as a primer that covers irregularities on the surface 10.

[0025] Mesh-like body application step (second step: FIG. 4(b)): Before the undercoat layer 20A (resin layer) is cured, the mesh-like body 3 is applied to the undercoat surface 20B. At this time, the mesh body 3 is applied so as not to bend or wrinkle, but since the undercoat surface 20B is smoothed by the above-mentioned undercoating step, the mesh body 3 can be easily applied.

[0026] Topcoat process (third process: Figure 4(c)): Before the undercoat layer 20A (resin layer) hardens, the resin agent 2A is applied to the undercoat surface 20B using a roller or brush, or the resin agent 2A is sprayed onto the undercoat surface 20B using a spray nozzle, and then applied as a finishing touch using a roller or brush to form the topcoat layer 20C (resin layer). In this topcoating step, the coating is applied so as to cover the mesh body 3 that has been applied in the mesh body 3 application step, and is applied so as to ensure that the mesh body 3 adheres securely to the undercoated surface 20B.

[0027] The overcoating step and the mesh body application step can also be carried out almost simultaneously. Specifically, when applying the mesh body 3 to the undercoated surface 20B, the mesh body 3 is applied while being pressed against the undercoated surface 20B using a roller or brush impregnated with the resin agent 2A, so that the mesh body 3 can be applied while being applied.

[0028] In the curing process (fourth process), after the topcoat process, the resin agent 2A gradually hardens while impregnating the applied mesh body 3, thereby forming a protective layer 2 in which the undercoat layer 20A (resin layer) and the topcoat layer 20C (resin layer) are integrated with the mesh body 3 embedded therein, as shown in Figure 1.

[0029] This construction method makes it possible to visualize the surface 10 of the concrete structure 1 from the outside, while preventing the peeling off of concrete pieces or finishing material pieces or the occurrence of cracks, and creating a surface protection structure A that is non-flammable or flame-retardant.

[0030] The surface protection structure A for concrete structures and the construction method of the surface protection structure A for concrete structures according to the present invention have been described in detail above with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the present invention also includes design changes within the scope of the present invention that do not deviate from the gist of the present invention. [Explanation of symbols]

[0031] A, A': Surface protection structure 1. Concrete structures 10 surface 11 Crack 2 protective layer 2A Resin Agent 20A Primer layer 20B Primed surface 20C Top coat 3 Reticulum 3A Weft 3B warp thread 3C mesh 3D Edge

Claims

1. A surface protection structure for a concrete structure in which a protective layer is laminated on the surface of the concrete structure, the protective layer is formed by embedding a mesh body in a resin layer, The resin layer has an elongation of 200% or more. A surface protection structure for a concrete structure.

2. 2. The surface protection structure for a concrete structure according to claim 1, wherein the resin layer has waterproof properties and moisture permeability.

3. 2. The surface protection structure for a concrete structure according to claim 1, wherein the resin layer is translucent.

4. 2. The surface protection structure for a concrete structure according to claim 1, wherein the resin layer is non-combustible or flame-retardant.

5. 5. The surface protection structure for a concrete structure according to claim 1, wherein the mesh size of the mesh body is 10 to 30 mm.

6. Cracks have occurred on the surface of the concrete structure, A surface protection structure for a concrete structure as described in any one of claims 1 to 4, characterized in that the protective layer is laminated at least at the location where the crack has occurred and in a predetermined area around it.

7. A construction method for a surface protection structure of a concrete structure in which a protective layer is laminated on the surface of the concrete structure, comprising: The method for constructing a surface protection structure for a concrete structure includes a primer step of applying a resin agent to the surface of the concrete structure to form a primer layer, a coating step of applying a reticulate body to the surface of the primer layer, a topcoat step of applying the resin agent used in the primer step to the surface of the primer layer and covering the reticulate body, and a curing step of curing the applied resin agent, The resin layer formed by curing the resin agent has an elongation of 200% or more. A method for constructing a surface protection structure for a concrete structure, comprising:

8. The surface of the concrete structure has cracks, A method for constructing a surface protection structure for a concrete structure as described in claim 7, characterized in that the protective layer is laminated at least on the surface of the concrete structure at the location where the crack has occurred and in a predetermined area surrounding the location.

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