JP5265909B2 - Concrete stripping prevention method - Google Patents

Description

The present invention relates to a concrete piece peeling prevention method for preventing a concrete piece from peeling off by adhering a net-like peeling prevention material to the surface side of a concrete frame, and more particularly, a primer having a quick drying property and an impregnation having elasticity and fast drying property. The present invention relates to a concrete piece peeling prevention method that reduces the number of construction days and improves the peeling prevention effect by adhering a peeling prevention material to the surface side of the concrete frame using a material.

Conventionally, concrete is widely used as the main structure of concrete structures such as bridge girders, columns, and tunnels. However, concrete may have defects such as cracks due to neutralization, earthquakes, cracks due to land subsidence and overload, collapse due to cracks, and partial missing. For this reason, conventionally, reinforcement or repair has been performed by embedding a net-like body using epoxy resin, resin mortar, mortar, or the like on the surface side of the concrete frame (see, for example, Patent Document 1 and Patent Document 2).
Japanese Patent Publication No. 60-5750 Japanese Examined Patent Publication No. 4-67546

  On the other hand, for example, in the former Metropolitan Expressway Public Corporation (organized on October 1, 2005, changed to the Metropolitan Expressway Co., Ltd.), the network is bonded to the surface side of the concrete frame only by the epoxy resin composition. In January 1989, the concrete floor slab drainage repair standard (draft) was created, and a glass cloth was bonded to the concrete structure surface with an epoxy resin composition (two-component epoxy resin composition). It was repaired by. Furthermore, in June 2000, the former Japan Highway Public Corporation (dissolved by the split privatization on October 1, 2005) created a “Concrete Fragment Prevention Measures Manual” and an epoxy resin composition (two-component epoxy). Fiber sheet adhesion by resin composition), waterproofing for peeling prevention, or steel plate installation was carried out. In addition, the manual of the former Japan Highway Public Corporation stated that glass cloth deteriorates due to the alkalinity of the concrete, so that the fiber sheet to be bonded is a vinylon mesh-like sheet (mesh-like vinylon sheet) that satisfies the conditions. ing. In the manuals of the former Metropolitan Expressway Public Corporation and the former Japan Highway Public Corporation, the fiber sheet (glass cloth, mesh vinylon sheet, etc.) is bonded to the concrete structure surface, and these It was common in the point that the flaking of the concrete piece was prevented by adhesion of the fiber sheet.

  However, as an epoxy resin composition used in the above-described methods (methods for preventing the flaking of concrete pieces), a two-pack type epoxy resin composition has been mainly used conventionally. When such a two-component epoxy resin composition is used, operations such as weighing and mixing of two types (epoxy resin and curing agent, etc.) are required, resulting in inferior workability. , Had various problems such as mixing errors and poor mixing. Due to such measurement errors, mixing errors, and poor mixing, the cured physical properties are lowered, and the adhesive effect of the original epoxy resin composition cannot be exhibited. Furthermore, since the two-pack type epoxy resin composition takes a long time to cure the resin, a certain curing period (for example, one day) is required when proceeding to the next step, and there is a drawback that the number of construction days becomes long. It was. For example, reinforcement and repair work for road tunnels and railway tunnels may take about 3 days in total.

Therefore, the present invention addresses such problems and adheres the anti-detachment material to the surface side of the concrete frame using a primer having quick drying properties and an impregnating material having elasticity and quick drying properties, thereby reducing the number of work days. An object of the present invention is to provide a concrete piece peeling prevention method that shortens and improves the peeling prevention effect.

In order to achieve the above object, the concrete piece exfoliation prevention method according to the first invention is a concrete piece exfoliation prevention method in which a net-like exfoliation prevention material is adhered to the surface side of a concrete frame to prevent the concrete piece from exfoliating. In addition, a step of applying a layer having a quick-drying primer that becomes tack-free within 2 hours after application to the surface of the concrete frame, and prevention of net-like peeling on the surface of the applied primer layer The step of arranging the material in layers, and the surface of the arranged anti-peeling material has elasticity with an elongation at the maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more and after application 2 A step of applying a layer of a resin having a quick-drying property that is tack-free within a time as an impregnating material for holding the anti-stripping material on the surface side of the concrete frame. Is.

With such a configuration, a primer having a quick-drying property that is tack-free within 2 hours after application is applied in layers to the surface of the concrete frame, and a net-like peeling prevention is applied to the surface of the applied primer layer. The materials are arranged in layers, and the surface of the arranged anti-peeling material has elasticity with an elongation at maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more and within 2 hours after application. By applying a layer of a resin that has a quick-drying property to be tack-free as an impregnating material for holding the peeling preventive material on the surface side of the concrete frame, it prevents the net-like peeling on the surface side of the concrete frame. The material is bonded and the punching strength of the bonding is set to 1.5 kN or more to prevent the concrete pieces from peeling off.

  Further, the above net-like peeling prevention material is provided with an adhesive layer on at least one side. Thereby, the net-like anti-peeling material provided with the pressure-sensitive adhesive layer on at least one side surface can be temporarily fixed by pressing the pressure-sensitive adhesive layer on the surface of the primer layer.

According to a second aspect of the present invention, there is provided a concrete piece peeling prevention method for preventing a concrete piece from peeling off by adhering a net-like peeling prevention material to the surface side of the concrete frame. A step of applying a layer having a quick-drying primer that becomes tack-free within 2 hours after application, and a layer of anti-stripping material on the surface of the applied primer layer On the surface of the arranged anti-peeling material, it has elasticity with an elongation at the maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more and is tack-free within 2 hours after application. A step of applying a resin having such a fast drying property as an impregnating material for holding the anti-slipping material on the surface side of the concrete frame, and the applied impregnating material layer And a step of applying a finish coating material in a layered manner to the surface.

With such a configuration, a primer having a quick-drying property that is tack-free within 2 hours after application is applied in layers to the surface of the concrete frame, and a net-like peeling prevention is applied to the surface of the applied primer layer. The materials are arranged in layers, and the surface of the arranged anti-peeling material has elasticity with an elongation at maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more and within 2 hours after application. Apply a layer of a fast-drying resin that is tack-free as an impregnating material to hold the anti-peeling material on the surface side of the concrete frame , and finish the surface of the applied impregnating material layer. By applying the coating material in layers, a net-like anti-stripping material is adhered to the surface side of the concrete casing, and the adhesion punching strength is 1.5 kN or more to prevent the concrete pieces from peeling off.

According to the invention of claim 1, on the surface of the concrete frame, a primer having a quick-drying property that becomes tack-free within 2 hours after application is applied in layers, and on the surface of the applied primer layer, flaking prevention material reticular arranged in layers, applied to the arrangement surface of the exfoliation prevention material, along with maximum tensile and ultimate tensile stress elongation at a load of 100% or more with a 1.0 N / mm ² or more elastic By applying a layer of a resin having a quick-drying property that becomes tack-free within 2 hours later as an impregnating material for holding the anti-stripping material on the surface side of the concrete case, the surface side of the concrete case is applied. It is possible to prevent the concrete piece from peeling off by adhering a net-like peeling prevention material and setting the adhesive punching strength to 1.5 kN or more. Here, since the primer has the quick-drying properties as described above, the primer is applied to the surface of the concrete frame and becomes tack-free within 2 hours. Then, the anti-peeling material for the next process is placed, and then the impregnating material is applied to the surface. The construction time can be shortened. In addition, since the impregnating material has the above-mentioned elasticity and quick-drying property , even if a crack occurs on the surface of the concrete frame, the impregnating material impregnated in the anti-debonding material cooperates with the net-like anti-detaching material. It can stretch elastically and follow the cracks to support the surface of the concrete frame. Further, the impregnating material is cured in a short time, and the peeling preventing material arranged in a layer on the surface of the primer layer can be adhered to the surface side of the concrete frame in a short time. Therefore, the construction days can be shortened as a whole, and the peeling prevention effect can be improved.

And according to the invention which concerns on Claim 3 , the primer which has quick-drying property which becomes tack-free within 2 hours after application | coating in the layer form is applied to the surface of a concrete frame, The surface of this applied primer layer In addition, a net-like anti-strip material is arranged in layers, and the surface of this anti-strip material has elasticity with an elongation at maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more. In addition , a resin having a quick-drying property that becomes tack-free within 2 hours after application is applied in a layer form as an impregnation material for holding the anti-detachment material on the surface side of the concrete frame , and this applied impregnation material layer By applying the finish coating material in layers to the surface of the concrete, a net-like anti-stripping material is adhered to the surface side of the concrete frame, and the punching strength of the adhesion is 1.5 kN or more to prevent the concrete pieces from peeling off. can do. Here, since the primer has the quick-drying properties as described above, the primer is applied to the surface of the concrete frame and becomes tack-free within 2 hours. Then, the anti-peeling material for the next process is placed, and then the impregnating material is applied to the surface. The construction time can be shortened. In addition, since the impregnating material has the above-mentioned elasticity and quick-drying property , even if a crack occurs on the surface of the concrete frame, the impregnating material impregnated in the anti-debonding material cooperates with the net-like anti-detaching material. It can stretch elastically and follow the cracks to support the surface of the concrete frame. Further, the impregnating material is cured in a short time, and the peeling preventing material arranged in a layer on the surface of the primer layer can be adhered to the surface side of the concrete frame in a short time. Moreover, since the said impregnating material hardens | cures in a short time, a finish coating material can be apply | coated to the surface of the impregnating material layer in a short waiting time. Therefore, the construction days can be shortened as a whole, and the peeling prevention effect can be improved. Further, the finished surface of the concrete frame can be cleaned by the finish coating material applied to the surface of the impregnating material layer.

Furthermore, according to the invention which concerns on Claim 2 or 4 , the net-like peeling prevention material is provided with the pressure-sensitive adhesive layer on at least one side surface, so that the net-like peeling prevention material provided with the pressure-sensitive adhesive layer is provided. Can be temporarily fixed by pressing the pressure-sensitive adhesive layer on the surface of the primer layer. Thereby, construction can be easily advanced without using a separate means for temporarily fixing the net-like anti-stripping material to the surface of the primer layer. Therefore, the construction days can be shortened as a whole.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a process diagram showing a first embodiment of a concrete stripping prevention method according to the present invention. This concrete piece exfoliation prevention method is to prevent the exfoliation of concrete pieces by adhering a net-like anti-exfoliation material to the surface side of the concrete frame, and using a primer that has quick drying properties and an impregnating material that has elasticity to prevent exfoliation. The material is bonded to the surface side of the concrete frame. Hereinafter, the concrete stripping prevention method according to the first embodiment will be described with reference to FIG.

  First, FIG. 1A is a cross-sectional view showing a concrete structure 1 that constitutes an inner wall of a concrete structure, for example, a road tunnel or a railway tunnel, before the concrete stripping prevention method according to the first embodiment is applied. is there.

  First, as shown in FIG.1 (b), the primer 2 which has quick-drying property which becomes tack free within 2 hours after application | coating is applied to the surface of such a concrete housing 1 in layers. The primer 2 is a paint for reinforcing the base when the coating material is applied repeatedly, and is made of, for example, a treating agent containing a one-pack type epoxy resin composition containing an epoxy resin and a ketimine compound. And this primer 2 has quick-drying property which becomes tack-free within 2 hours (23 degreeC) after apply | coating to a target object. Here, tack-free means a state in which stickiness does not occur even when the surface of the paint applied to the object is touched. In this tack-free test, the sample was applied evenly on a glass plate with a thickness of about 3 mm without bubbles, placed in an atmosphere around 23 ° C., and cleaned with ethyl alcohol. Then, lightly touch the three points on the surface of the sample and measure the time required from when the sample is leveled to when the sample does not adhere to the fingertip (see JIS A 1439 “Tack-Free Test”). Therefore, the quick-drying property of the primer 2 in this embodiment is such that it is tack-free (the paint does not adhere to the fingertip) within 2 hours after being applied to the surface of the concrete case 1 and left as it is.

  Next, as shown in FIG.1 (c), the net-like peeling prevention material 3 is arrange | positioned in layers on the surface of the primer layer (2) applied as mentioned above. This exfoliation preventive material 3 is bonded to the surface side of the concrete case 1 to prevent the concrete pieces from exfoliating when cracks are generated on the surface of the concrete case 1. For example, as shown in FIG. The yarns 3a, 3b, 3c of the book are woven into a triaxial net that intersects in a net shape.

  Such a peeling prevention material 3 is not particularly limited, and various materials, fabrics, and the like can be appropriately selected and used depending on the intended degree of peeling prevention effect. Examples of the stripping prevention material 3 include sheets having various shapes such as a woven cloth sheet (fiber sheet or the like), a nonwoven sheet, a net or mesh sheet (sometimes referred to as a “net sheet”). Planar body) can be used. In the woven fabric sheet, a woven fabric sheet having a large porosity corresponds to a net-like sheet.

  The net-like sheet may be a non-woven cloth-like net-like sheet, but is preferably a braided cloth-like net-like sheet in order to enhance the peeling prevention effect. In the net-like sheet, various lattice shapes such as a triangle, a quadrangle, and a hexagon can be used. Such lattices may be formed regularly or irregularly. Further, the size (or porosity) of the lattice is not particularly limited, and can be appropriately selected according to the intended degree of anti-peeling effect. For example, when the lattice is an equilateral triangle, the degree (the length of one side of the equilateral triangle of the lattice) can be selected from a range of about 3 to 300 mm (preferably 5 to 50 mm). When the lattice has another shape, the mesh can be set according to the regular triangle.

  In a sheet of various shapes such as a woven fabric sheet, a nonwoven fabric sheet, and a net sheet, the porosity may be, for example, about 10 to 90% (preferably 50 to 80%).

  In addition, as the peeling prevention material 3, a continuous sheet is preferable. If it is a continuous sheet, the effect of preventing the concrete pieces from peeling off can be further enhanced.

  Moreover, as a material of the peeling prevention material 3, carbon fiber, plastic fiber [for example, aramid fiber, vinylon fiber, polyethylene fiber sheet (especially fiber sheet made of high impact type polyethylene), polyimide fiber sheet, etc.), glass fiber, etc. A variety of fibers can be used. Further, the peeling prevention material 3 may be composed of only a single type of fiber, or may be composed of a plurality of types of fiber.

Finally, as shown in FIG. 1 (d), on the surface of the anti-peeling material 3 arranged as described above, the elongation at the maximum tensile load is 100% or more and the maximum tensile stress is 1.0 N / mm ² or more. A resin having the following elasticity is applied as an impregnating material 4 in layers. The impregnating material 4 is impregnated in the state of being applied to the anti-debonding material 3 and is used for holding the anti-debonding material 3 on the surface side of the concrete casing 1. For example, a one-component acrylic modified polyurethane resin composition It consists of a processing agent containing a product. The impregnating material 4 has elasticity having an elongation at the maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more. The term “elasticity” as used herein refers to the property that the elongation when the maximum tensile load is applied to the test piece is at least twice the original length, and the maximum tensile stress is 1.0 N / mm ² or more. This elasticity test can be performed based on “Tensile test method for vulcanized rubber” defined in JIS K 6251. For example, the impregnating material 4 in the embodiment is filled into a sheet, cured by curing at 23 ° C. × 3 days + 50 ° C. × 4 days, and this cured product is punched with a No. 3 type dumbbell and tested. The tensile test is performed at a test temperature of 23 ° C. and a tensile speed of 200 mm / min.

  Examples of the elastic material used as the impregnating material 4 include a polyurethane resin, a modified silicone resin, or a modified silicone-epoxy resin, in addition to the acrylic-modified polyurethane resin.

  As shown in FIG. 1 (d), the impregnating material 4 is left in a state of being applied in a layer form on the surface of the anti-peeling material 3, and the impregnating material 4 is dried and hardened to complete the process of the concrete piece anti-peeling method. To do. Thereby, the net-like exfoliation preventing material 3 can be adhered to the surface side of the concrete housing 1 to prevent the concrete pieces from exfoliating. In this case, since the primer 2 has the quick-drying property as described above, the primer 2 is applied to the surface of the concrete housing 1 and becomes tack-free within 2 hours, and the anti-peeling material 3 in the next process is disposed, and then the surface is applied to the surface. The impregnating material 4 can be applied, and the construction time can be shortened. In addition, since the impregnating material 4 has the elasticity as described above, even if a crack occurs on the surface of the concrete housing 1, the impregnating material 4 impregnated in the anti-debonding material 3 and the net-like anti-detaching material 3 cooperate. It can elastically expand and contract and follow the crack to support the surface of the concrete housing 1. Therefore, the construction days can be shortened as a whole, and the peeling prevention effect can be improved.

  FIG. 3 is a process diagram showing a second embodiment of the concrete stripping prevention method according to the present invention. In this concrete piece peeling prevention method, the steps of FIGS. 3A to 3D are the same as the steps of FIGS. 1A to 1D described above, but finally the surface of the impregnating material 4 is finish-coated. A process of applying material is added. That is, after the step of FIG. 3 (d), as shown in FIG. 3 (e), the finish coating material 5 is layered on the surface of the impregnating material layer (4) applied to the surface of the peeling prevention material 3. Apply to. This finish coating material 5 is a coating for finishing the surface of the impregnated material layer (4), and thereby improves the appearance after the peeling prevention method is applied.

The impregnated material 4 applied in the steps shown in FIGS. 1 (d) and 3 (d) has elasticity such that the elongation at the maximum tensile load is 100% or more and the maximum tensile stress is 1.0 N / mm ² or more. At the same time, it is desirable that the resin be quick-drying so as to be tack-free within 2 hours after application. Thus, by applying the impregnating material 4 made of the resin having the above-mentioned elasticity and quick-drying property to the surface of the exfoliation preventing material 3, the impregnating material 4 is cured in a short time, and the primer layer (2) The peeling prevention material 3 arranged in a layer on the surface can be adhered to the surface side of the concrete housing 1 in a short time. Therefore, the construction days can be shortened. In particular, in the case shown in FIG. 3 (d), since the impregnating material 4 is cured in a short time, the finish coating material 5 shown in FIG. 3 (e) is applied to the surface of the impregnating material layer (4) with a short waiting time. Can be applied. Therefore, the construction days can be further shortened as a whole.

Moreover, as for the net-like peeling prevention material 3 arrange | positioned at the process shown in FIG.1 (c) and FIG.3 (c), it is desirable that the adhesive layer is provided at least on one side. In this case, the net-like exfoliation preventing material 3 provided with the pressure-sensitive adhesive layer can be temporarily fixed by pressing the pressure-sensitive adhesive layer on the surface of the primer layer (2). Thereby, construction can be easily advanced without using a separate means for temporarily fixing the anti-peeling material 3 to the surface of the primer layer (2). Therefore, the construction days can be shortened as a whole. As the pressure-sensitive adhesive, for example, an emulsion type acrylic pressure-sensitive adhesive may be used. Then, for example, by applying an emulsion acrylic adhesive at 100 g / m ² on one side of the anti-peeling material 3 woven into a triaxial net and drying, the anti-peeling material 3 having an adhesive layer is obtained. (See Patent Publication No. 3973542, owned by the present applicant).

  Hereinafter, examples of the concrete stripping prevention method according to the present invention will be described with reference to a comparative table (FIG. 4) evaluated in comparison with comparative examples.

Example 1
As a primer 2, a treating agent containing a one-pack type epoxy resin composition containing an epoxy resin and a ketimine compound as a paint having a quick-drying property that becomes tack-free in one hour (23 ° C.) after coating. Using. As the reticulated anti-stripping material 3, an emulsion type acrylic pressure-sensitive adhesive was applied at 100 g / m ² on one side of a reticulated body woven into a triaxial net and dried to form a pressure-sensitive adhesive layer. As the impregnating material 4, an elastic resin having an elongation at a maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more was used. Specifically, the polyurethane resin has a tack-free time of 3 hours 30 minutes, an elongation at the maximum tensile load of 1000%, and a maximum tensile stress of 1.5 N / mm ² . The finish coating material 5 is not applied to the surface of the impregnation material layer (4).

(Example 2)
As a primer 2, a treating agent containing a one-pack type epoxy resin composition containing an epoxy resin and a ketimine compound as a paint having a quick-drying property that becomes tack-free in one hour (23 ° C.) after coating. Using. As the reticulated anti-stripping material 3, an emulsion type acrylic pressure-sensitive adhesive was applied at 100 g / m ² on one side of a reticulated body woven into a triaxial net and dried to form a pressure-sensitive adhesive layer. As the impregnating material 4, a resin having an elasticity with an elongation of 100% or more at the maximum tensile load and a maximum tensile stress of 1.0 N / mm ² or more and a quick-drying property that is tack-free within 2 hours after application. Was used. Specifically, it is an acrylic-modified polyurethane resin having a tack-free time of 50 minutes, an elongation at the maximum tensile load of 650%, and a maximum tensile stress of 1.5 N / mm ² . The finish coating material 5 is not applied to the surface of the impregnation material layer (4).

(Example 3)
As a primer 2, a treating agent containing a one-pack type epoxy resin composition containing an epoxy resin and a ketimine compound as a paint having a quick-drying property that becomes tack-free in one hour (23 ° C.) after coating. Using. As the reticulated anti-stripping material 3, an emulsion type acrylic pressure-sensitive adhesive was applied at 100 g / m ² on one side of a reticulated body woven into a triaxial net and dried to form a pressure-sensitive adhesive layer. As the impregnating material 4, an elastic resin having an elongation at a maximum tensile load of 100% or more and a maximum tensile stress of 1.0 N / mm ² or more was used. Specifically, the polyurethane resin has a tack-free time of 3 hours 30 minutes, an elongation at the maximum tensile load of 1000%, and a maximum tensile stress of 1.5 N / mm ² . The finish coating material 5 was applied to the surface of the impregnating material layer (4).

Example 4
As a primer 2, a treating agent containing a one-pack type epoxy resin composition containing an epoxy resin and a ketimine compound as a paint having a quick-drying property that becomes tack-free in one hour (23 ° C.) after coating. Using. As the reticulated anti-stripping material 3, an emulsion type acrylic pressure-sensitive adhesive was applied at 100 g / m ² on one side of a reticulated body woven into a triaxial net and dried to form a pressure-sensitive adhesive layer. As the impregnating material 4, a resin having an elasticity with an elongation of 100% or more at the maximum tensile load and a maximum tensile stress of 1.0 N / mm ² or more and a quick-drying property that is tack-free within 2 hours after application. Was used. Specifically, it is an acrylic-modified polyurethane resin having a tack-free time of 50 minutes, an elongation at the maximum tensile load of 650%, and a maximum tensile stress of 1.5 N / mm ² . The finish coating material 5 was applied to the surface of the impregnating material layer (4).

(Comparative example)
This corresponds to the prior art, and a two-pack type epoxy resin composition in which a conventional epoxy resin and a curing agent are mixed is used as a primer. This does not have quick drying. As the reticulated anti-stripping material, an emulsion-type acrylic pressure-sensitive adhesive was applied at 100 g / m ² on one side of a net woven into a triaxial net and dried to form a pressure-sensitive adhesive layer. As the impregnating material, a two-pack type epoxy resin composition in which a conventional epoxy resin and a curing agent were mixed was used in the same manner as the primer. This also does not have quick drying properties. A finish coating material was applied to the surface of the impregnating material layer.

(Evaluation)
Here, the concrete board to which the anti-peeling material obtained in Examples 1 to 4 and the comparative example was bonded was applied to the following “Punching test method for continuous fiber sheet bonding” and “cracking followability of surface covering material”. By the “Test method (draft)”, the adhesive strength of the net-like peeling prevention material was measured.

(Punching test method for continuous fiber sheet bonding)
This is in accordance with the standards of the former Japan Highway Public Corp. Test Institute, and stipulates a peeling prevention push-out test method for evaluating the peeling prevention performance of continuous fiber sheet adhesion used for concrete piece peeling prevention measures. The specimen is prepared as follows. The center part of the reinforced concrete U-shaped lid is cored with a core cutter for concrete with a diameter of 100mm. The core removal direction should be 55 ± 0.5mm deep from the back (opposite the continuous fiber sheet bonding surface). Surface treatment is applied to the surface of continuous fiber sheet bonding. Prevent flaking according to the specifications for continuous fiber sheet bonding. After completion of continuous fiber sheet bonding, the U-shaped lid is immersed for 30 mm and cured for the required period. The test method is as follows. Set the specimen so that there is no play on the H-shaped steel with a span of 400 mm. Loading is performed at a speed of 1 mm / min until the U-shaped lid breaks. Then, load at 5 mm / min, perform a punching test, and measure the maximum punching load. If the final load bearing capacity is confirmed, the test is terminated at that point. The measurement result by this test method is indicated by a numerical value (kN) in the “punch strength” column of the comparison table shown in FIG.

(Crack followability test method for surface coating materials (draft))
This is based on the Japan Society of Civil Engineers standards set forth in the “Concrete Standard Specification” established in 2007 by the Japan Society of Civil Engineers. A test substrate (hereinafter referred to as “substrate”) is prepared in the following manner. A substrate prepared in accordance with the method specified in JIS R 5201 is molded using a metal mold of 40 × 120 × 10 mm. It is cured for 24 hours at a temperature of 20 ± 2 ° C. and a relative humidity of 80% or more, then demolded, and then cured in water at a temperature of 20 ± 2 ° C. for 6 days. After completion of underwater curing, cure at a temperature of 23 ± 2 ° C and relative humidity of 50 ± 5% for 7 days or more, cut a 5mm depth cut with a diamond cutter on the surface opposite to the surface coated with the surface coating material, and fold the substrate Cut into two. The two cut substrates are brought into contact with each other on a steel plate or a stainless steel plate, and the entire side surface is wound and fixed with an adhesive tape. Thereafter, the material is not allowed to flow into the cut surface, and a surface coating material is applied leaving 30 mm at both ends, and cured for 7 days at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%. The test method is as follows. Either remove the specimen from the steel plate or stainless steel plate and fix it on a tensile tester, pull it at a constant speed of 5 mm / min, break the surface coating material, or partially break it, or show the maximum tensile strength The elongation (mm) is measured from the tensile stress-elongation curve. The measurement result by this test method is indicated by a numerical value (mm) in the “crack followability” column of the comparison table shown in FIG.

  From the comparison table shown in FIG. 4, in the comparative example corresponding to the prior art, the punching strength was 2.5 kN, and the crack followability was 2 mm. The construction takes about 1 day for drying the primer, about 1 day for drying the impregnating material, and about 1 day for drying the finish coating material, and it takes about 3 days in total.

  On the other hand, in Example 1, the punching strength is 1.7 kN, and the crack followability is 16.0 mm. The construction days are about 1 hour for drying the primer, about 3.5 hours for drying the impregnating material, and about 1 day as a whole without the finish coating material. Further, in Example 2, the punching strength is 2.6 kN, and the crack followability is 14.8 mm. The construction days are about 1 hour for drying the primer, about 1 hour for drying the impregnating material, and no finishing coating material, and less than one day as a whole (about 3 hours at the shortest). Further, in Example 3, the punching strength is 1.7 kN, and the crack followability is 16.0 mm. The construction takes about 1 hour to dry the primer, about 3.5 hours to dry the impregnating material, and about 1 day to dry the finish coating material, and it takes about 2 days in total. In Example 4, the punching strength is 2.6 kN, and the crack followability is 14.8 mm. Then, the number of construction days is about 1 hour for drying the primer, about 1 hour for drying the impregnating material, and about 1 day for drying the finish coating material, which is about 1 day as a whole.

  From these comparison results, in Examples 1 to 4 of the present invention, the punching strength is 1.7 kN or more, and the crack followability is markedly improved from 2 mm to 14.8 mm or 16.0 mm. It can be seen that the anti-peeling effect is improved. Moreover, while the construction days are about 3 days as a whole in the comparative example, in Examples 1 to 4 of the present invention, it is 1 day to 2 days, and it can be seen that the construction period is shortened. In particular, in the case of Example 2, it is less than one day (the shortest is about 3 hours) in the absence of the finish coating material, and in the case of Example 4, it is about 1 day even with the finish coating material. Construction days have been shortened. Therefore, for example, in the reinforcement and repair work of road tunnels and railway tunnels, the work can be completed in one day, and the period of road traffic restriction and train stoppage can be greatly shortened.

It is process drawing which shows 1st embodiment of the peeling prevention method of the concrete piece by this invention. It is a top view which shows the net-like peeling prevention material used for the peeling prevention construction method of the said concrete piece. It is process drawing which shows 2nd embodiment of the peeling prevention method of the said concrete piece. It is a comparison table | surface which shows the content evaluated by comparing the Example of the peeling prevention method of a concrete piece by this invention, and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Concrete frame 2 ... Primer 3 ... Net-like peeling prevention material 4 ... Impregnation material 5 ... Finish coating material

Claims (4)

A concrete piece peeling prevention method in which a net-like peeling prevention material is adhered to the surface side of a concrete frame to prevent the concrete piece from peeling off,
Applying a layer of a primer having a quick-drying property that is tack-free within 2 hours after application to the surface of the concrete frame;
On the surface of the applied primer layer, a step of arranging a net-like anti-stripping material in layers,
The surface of the anti-slipping material is 100% or more in elongation at the maximum tensile load and has a maximum tensile stress of 1.0N / mm ² or more, and is tack-free within 2 hours after application. A step of applying a resin having a quick drying property in layers as an impregnating material for holding the anti-peeling material on the surface side of the concrete frame ,
A method for preventing delamination of concrete pieces characterized by comprising Spalling prevention material of the mesh is spalling prevention method of the concrete piece according to claim 1, wherein the pressure-sensitive adhesive layer on at least one side is provided. A concrete piece peeling prevention method in which a net-like peeling prevention material is adhered to the surface side of a concrete frame to prevent the concrete piece from peeling off,
Applying a layer of a primer having a quick-drying property that is tack-free within 2 hours after application to the surface of the concrete frame;
On the surface of the applied primer layer, a step of arranging a net-like anti-stripping material in layers,
The surface of the anti-slipping material is 100% or more in elongation at the maximum tensile load and has a maximum tensile stress of 1.0N / mm ² or more, and is tack-free within 2 hours after application. A step of applying a resin having a quick drying property in layers as an impregnating material for holding the anti-peeling material on the surface side of the concrete frame ,
A step of applying a finish coating material in layers on the surface of the applied impregnation layer,
A method for preventing delamination of concrete pieces characterized by comprising 4. The concrete piece peeling prevention method according to claim 3 , wherein the netlike peeling prevention material is provided with an adhesive layer on at least one side.

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