JP4347757B2 - Concrete detachment prevention mesh-like fabric and concrete detachment prevention method using the same - Google Patents

Description

  The present invention relates to a concrete-stripping-preventing mesh-like fabric that adheres to a concrete structure in order to prevent the concrete structure from peeling off, and a concrete-stripping prevention method using the same.

In concrete structures, the reinforcing bars placed inside the concrete may rust due to the neutralization of the concrete, the intrusion of moisture, and other causes after the concrete has been placed. There is a strong risk of cracking and progressing, and eventually the concrete piece coming off. In addition, when an alkali-aggregate reaction occurs, many turtle-shaped cracks are generated on the surface. In recent years, accidents have occurred in various places where the surface layer of a concrete structure, which has acquired many years after construction, deteriorates and peels off.
After repairing the surface of concrete members that have cracked concrete structures such as roadbeds and bridge piers, construction work has been carried out, such as pasting reinforcement materials. In terms of economy, the reinforcing agent is expensive because it must use an adhesive such as a resin with good adhesion to the concrete structure, or it is reinforced during service. There was a problem.
Thereby, it is considered to repair the cracked concrete member by attaching a mesh or mesh fabric member to the surface of the cracked concrete member.

For example, according to Patent Document 1 , the surface of a reinforcing portion of a concrete structure is cleaned, and organic fibers such as polyester fiber, polypropylene fiber, amyrad fiber, and vinylon fiber, inorganic fibers such as glass fiber and metal fiber, or carbon fibers. Without weaving fibers with fibers arranged in three axes, four axes, or five axes, etc., the laminated fabric is integrally laminated by crossing the axial direction with the adhesive or adhesive tape on the surface of the concrete structure After installation, the fabric is impregnated with a liquid thermosetting resin to be cured and / or a laminated fabric impregnated with a pre-laminated liquid thermosetting resin is attached to the surface of the concrete structure for thermosetting Since it is not a woven fabric by curing the resin, the strength does not decrease much even if a tensile force is applied to the fabric in any direction from the outside. Only Only at the construction is easy to integrate with a thermosetting resin, reinforced concrete structure of the high strength. As liquid thermosetting resins, there are disclosed radical curable resins such as unsaturated polyester resins, epoxy acrylate resins, urethane acrylate resins, and acrylic syrup resins, or epoxy resins and phenol resins.
In general, the concrete surface that has been peeled off is repaired and a primer is applied. Remove the unevenness of the base with a correction material, undercoat, apply a net-like or mesh-like fabric, and apply overcoat and harden. The undercoat and topcoat resins are repaired by applying an epoxy resin or MMA (methyl methacrylate) resin.
In order to affix the mesh fabric to the concrete structure, it is disclosed that an adhesive is applied to the surface of the concrete structure and affixed, or the mesh fabric is point-bonded at a plurality of locations with an adhesive or an adhesive tape. ing.
JP 2001-329511 A

Conventionally, when a net-like or mesh-like cloth is attached to the surface of deteriorated concrete and overcoated with a resin or the like, an adhesive or an adhesive tape is attached to the concrete surface to fix the mesh-like cloth. However, not only can construction be performed by two or more people at the time of construction, but also due to partial adhesion, the mesh fabric is difficult to adhere to the concrete surface and may be peeled off during overcoating.

The present invention
“1. The total number of yarns per axis is 300-10000 decitex synthetic fibers, glass fibers, or carbon fibers, the number of axes is 2-4 axes, and the mesh is 2-20 mm mesh A mesh-like fabric for preventing concrete peeling, wherein an ethylene-vinyl acetate copolymer emulsion or an acrylic resin emulsion is applied or impregnated on a woven fabric, and an adhesive layer is formed on one side by applying an adhesive.
2. The mesh fabric for preventing concrete peeling according to item 1, wherein at least one axis of the mesh fabric is entangled weave.
3. The mesh fabric has a tensile strength of 500 to 2000 N per 5 cm width, and an elongation of 20 to 6
3. A mesh-like fabric for preventing concrete peeling, which is 0%, described in item 1 or item 2 .
4). Concrete was stuck to a release paper to form the surface of the pressure-sensitive adhesive layer of flaking prevention meshed fabric, according to any one of no counts 1 to 3 wherein, concrete spalling prevention meshed fabric.
5. Apply the adhesive layer of the mesh fabric for preventing concrete peeling described in any one of items 1 to 4 to the surface to be treated of the concrete structure, and then apply the surface treatment agent on the fabric. Concrete peeling prevention construction method characterized by doing. "
About.

When the fabric to which the pressure-sensitive adhesive of the present invention is applied is used to adhere to a concrete structure, the fabric is evenly adhered, and the fabric is difficult to peel off even during overcoating, and construction can be simplified.
The term “top coating” as used in the present invention refers to applying a surface treatment agent in order to integrate the concrete structure and the fabric provided with the adhesive portion.

Meshed fabric of the present invention relates to separation of the concrete structure, for use in method of solidifying at concrete and stretched a mesh fabric in the concrete surface to prevent the spalling base fabric woven manufacturing synthetic fibers or carbon fibers and, it an ethylene - vinyl acetate copolymer emulsion or a mesh-like fabric coated with acrylic resin emulsion.
The synthetic fibers used for the base fabric are preferably polyethylene fibers or polypropylene fibers for polyolefins, nylon fibers and aramid fibers for aliphatic and aromatic polyamides, vinylon fibers for polyvinyl alcohols, and PET fibers for polyesters. Among these, nylon is more preferable because it is excellent in alkali resistance.
The woven fabric of the mesh-like fabric for preventing concrete peeling of the present invention has a mesh shape in which the total yarn amount per axis is 300 to 10000 dtex, the number of axes is 2, 3 or 4 axes, and the mesh is 2 to 20 mm. Although it is a cloth, if the total yarn amount per axis is 300 dtex or less, the tensile strength is insufficient, and if it is 10,000 dtex or more, the cloth becomes too strong and difficult to bend. Four or more axes are not preferable because voids are reduced and penetration of the surface treatment agent is reduced. If the mesh is 2 mm or less, the penetration of the surface treatment agent is reduced, and if it is 20 mm or more, the adhesive layer has low adhesion, which is not preferable.
Arbitrary preferred because fixation of the at least one axis of the mesh-like fabric is leno weave and the coating agent is increased.

The axis of the mesh-like fabric referred to in the present invention is a warp, a weft, or a diagonal thread.
Fabric mesh fabric, ethylene - vinyl acetate copolymer emulsion or coating the acrylic resin emulsion. It is preferable to coat with these emulsions because the water resistance effect is exhibited. The coating amount of the emulsion is 20 to 100 parts by weight based on the base fabric.
The tensile strength of the fabric must be 500-2000 N / 5 cm wide. 500N
If the width is less than / 5 cm, the strength is insufficient, and if the width is greater than 2000 N / 5 cm, the cloth becomes stiff.
The elongation is 20 to 60%, and if it is 20% or less, it becomes impossible to cope with the change in elongation at the time of sticking, and if it is 60% or more, the affinity with the coating material is deteriorated.
The method of using the mesh fabric for preventing concrete peeling of the present invention will be described. The mesh fabric is used by sticking to the surface of the concrete structure.

As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, acrylic or rubber-based pressure-sensitive adhesives can be used, and these pressure-sensitive adhesives are any of a solvent type, a water dispersion type, and a hot melt type. Also good. The acrylic pressure-sensitive adhesive usually has a non-crosslinked type and a crosslinked type, but a crosslinked type crosslinked with a curing agent is preferred. An acrylic adhesive is an alkyl acrylate or methacrylate having 4 to 12 carbons, the main component of which is an acrylate ester and produces a polymer having a low Tg as the main monomer, and includes 2-ethylhexyl acrylate, butyl acrylate, acrylic acid A copolymer of a monomer such as isooctyl and a monomer having a short T-chain, such as an acrylic acid ester, methacrylic acid ester, vinyl acetate, or styrene, having a high Tg and a functional group is used.
Examples of the rubber-based pressure-sensitive adhesive include natural rubber pressure-sensitive adhesives, styrene-butadiene random copolymer (SBR) pressure-sensitive adhesives, polyisobutylene-based pressure-sensitive adhesives (PIB), and butyl rubber-based pressure-sensitive adhesives, and SBR pressure-sensitive adhesives are preferable. In both cases of the solvent type and the water-dispersed type, an adhesive is applied on a release fabric and dried to form an adhesive layer, and then the adhesive layer is transferred and laminated on the fabric. When not using transfer, a solvent type or water dispersion type adhesive is directly applied to the fabric. The application amount of the pressure-sensitive adhesive is 10 to 100 g / m ² , preferably 10 to 80 g / m ² , and more preferably 20 to 70 g / m ² .
As the curing agent for crosslinking the acrylic pressure-sensitive adhesive layer, an isocyanate-based curing agent is preferable. is there. If holding torque releases peeling large in 0.5 parts by weight or less, the adhesive remains stuck kimono. If it is 7 parts by weight or more, the holding force becomes small and the function as an adhesive tape is not achieved.
The method of using the mesh fabric for preventing concrete peeling of the present invention will be described. The mesh-like fabric for preventing concrete peeling is used by sticking to a concrete structure. For example, the mortar or jumper on the concrete surface is removed by scouring and the construction surface is cleaned. The release paper is peeled off, and the concrete-like mesh fabric for preventing flaking is attached to the cleaned concrete surface. A surface treatment agent is applied as a top coat to a mesh fabric for preventing concrete from peeling off.

As the surface treatment agent, cement-based mortar, epoxy resin, acrylic resin, etc., particularly resin-based cement mortar of cement-based material, has good adhesion to concrete.
The surface treatment agent is applied when the surface treatment agent covers the fabric, the concrete structure is applied and coated around the fabric to integrate the concrete structure and the fabric, and the concrete structure surface is cracked. This is because moisture and the like do not enter the concrete structure.

Example 1
Acrylic resin is applied to a mesh-like woven fabric having a number of axes of 4 and a mesh size of 80 mm woven using nylon multifilament with a yarn amount of 8000 dtex, and an isocyanate curing agent is applied to a cross-linked acrylic adhesive on one side, and adhesive 100 A curable pressure-sensitive adhesive with 4 parts by weight added to parts by weight was coated with 80 g / m ² to obtain a mesh fabric.
The back surface of the roadbed of the overpass where the concrete has been peeled or dropped off is scraped and cleaned, and the mesh fabric is pressed against the concrete surface and attached. At this time, it must be stuck so that no air remains between the concrete surface and the fabric. After sticking, a surface treatment agent in which an acrylic resin emulsion is added to cement-based mortar is applied to the fabric and its peripheral concrete structure to coat and integrate the fabric and its peripheral concrete structure.
There is no delamination of concrete from such treated concrete structures.

  The number of concrete structures will continue to increase and cannot be reduced. And with the passage of time, the concrete structure deteriorates, causing peeling and dangerous. It can be understood that the present invention is widely used in concrete peeling prevention work because the cloth can be easily attached to the concrete surface and can be used without being peeled off during the overcoating operation.

Claims (5)

The total number of yarns per axis is 300 to 10000 dtex synthetic fibers, glass fibers, or carbon fibers formed from 2 to 4 axes. -A concrete stripping prevention mesh that is formed by applying or impregnating a vinyl acetate copolymer emulsion or an acrylic resin emulsion and then applying an acrylic or rubber adhesive on one side to form an adhesive layer. Fabric. The mesh fabric for preventing concrete peeling according to claim 1, wherein at least one axis of the mesh fabric is entangled weave. The mesh fabric for preventing concrete peeling according to claim 1 or 2, wherein the mesh fabric has a tensile strength of 500 to 2000 N per 5 cm width and an elongation of 20 to 60%. The mesh fabric for preventing concrete stripping according to any one of claims 1 to 3, wherein a release paper is attached to the surface of the mesh fabric for preventing concrete stripping on which the pressure-sensitive adhesive layer is formed. The adhesive layer of the mesh fabric for preventing concrete peeling described in any one of claims 1 to 4 is applied to a surface to be treated of a concrete structure, and then a surface treatment agent is applied on the fabric. Concrete peeling prevention construction method characterized by doing.