JP7630231B2 - Concrete reinforcement, concrete structure having concrete reinforcement, and method for manufacturing the same - Google Patents

Description

The present invention relates to a concrete reinforcing material that is embedded in a concrete structure, a concrete structure that uses this reinforcing material, and a method for manufacturing the same.

Concrete materials are generally strong in compression but weak in tension. When concrete materials are subjected to deformation stresses such as bending, not only compressive stress but also tensile stress is simultaneously applied, so that areas that receive a certain level of tensile stress suffer irreversible deterioration and damage, and as a result, there is a risk that the functionality of the concrete material will be reduced or lost. For this reason, concrete materials are generally reinforced. There are various forms of reinforcement, such as reinforcement by using reinforcing bars or steel frames in combination, reinforcement by covering the concrete material with a sheet-like or mesh-like sheet of high-strength, high-elasticity fiber, or reinforcement by enclosing such a sheet or mesh in the concrete material.

Patent Document 1 discloses a concrete reinforcing material that is placed near the surface of a concrete structure, and that can be easily placed in an appropriate position along the inner surface of the formwork when pouring concrete, and that is expected to have sufficient adhesion to the concrete.

The fibers used in conventional reinforcing materials are limited to those with high tensile strength and tensile modulus, and for example, metal fibers, aramid fibers, carbon fibers, glass fibers, and basalt fibers have been mainly used.

Patent Document 2 discloses a method for reinforcing a structure by bonding and integrating a fiber-reinforced sheet onto the surface of the structure. Patent Document 2 describes the use of carbon fiber, glass fiber, basalt fiber, metal fiber, and organic fibers such as aramid as reinforcing fibers.

JP 2001-232624 A JP 2011-208352 A

As mentioned above, conventional concrete reinforcement materials use fibers with high tensile strength and tensile modulus to compensate for the characteristic of concrete material, which is strong in compression but weak in tension. However, there is room for improvement in conventional concrete reinforcement materials in terms of preventing spalling when the concrete material deforms or breaks, thereby further increasing safety.

In this context, the present disclosure aims to provide a concrete reinforcement material with improved spalling resistance and safety. The present disclosure also relates to a concrete structure having such a concrete reinforcement material, and a manufacturing method thereof.

The present inventors have examined the types and characteristics of fibers used in the reinforcing material and have found that by using specific fibers, it is possible to provide a concrete reinforcing material with improved spalling prevention and safety. More specifically, in addition to the conventional viewpoint of reinforcing concrete structures against strong external forces that cause them to deform or break, they have pursued a certain degree of rationality and superiority from the viewpoint of ensuring further safety during the process of deformation and destruction of concrete materials. As a result, they have found that a concrete reinforcing material with improved spalling prevention and safety can be provided by the concrete reinforcing material disclosed herein that has specific fibers, and have completed the present invention.

That is, the present disclosure achieves the above object by the following means:
<Aspect 1>
A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh body made up of linear bodies and protruding bodies distributed on a surface of the mesh body,
the protruding body protrudes in at least a direction perpendicular to a surface direction of the mesh body,
The linear body contains aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and has a total fineness of 3,500 decitex to 50,000 decitex.
Concrete reinforcement.
<Aspect 2>
The concrete reinforcing material according to aspect 1, wherein the linear bodies are threads formed by twisting the aliphatic resin fibers together, or strings formed by bundling the aliphatic resin fibers.
Aspect 3
The concrete reinforcing material according to claim 1 or 2, wherein the linear bodies contain aliphatic resin fibers formed from polyvinyl alcohol (PVA).
<Aspect 4>
3. The concrete reinforcement material according to claim 1, wherein the linear bodies contain aliphatic resin fibers formed from a polyolefin, and the polyolefin is polypropylene, polymethylpentene, or polyethylene.
<Aspect 5>
3. The concrete reinforcement material according to claim 1, wherein the linear bodies contain aliphatic resin fibers formed from a polyolefin, and the polyolefin is polypropylene.
Aspect 6
3. The concrete reinforcing material according to claim 1, wherein the linear bodies contain aliphatic resin fibers formed from a polyolefin, and the polyolefin is polymethylpentene.
Aspect 7
3. The concrete reinforcing material according to claim 1, wherein the linear bodies contain aliphatic resin fibers formed from a polyolefin, and the polyolefin is polyethylene.
<Aspect 8>
The concrete reinforcing material according to aspect 1 or 2, wherein the linear bodies contain aliphatic resin fibers formed from an aliphatic polyamide.
<Aspect 9>
A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh body made up of linear bodies and protruding bodies distributed on a surface of the mesh body,
the protruding body protrudes in at least a direction perpendicular to a surface direction of the mesh body,
The linear body is
An aliphatic resin fiber formed from one or more synthetic resins selected from polyvinyl alcohol, polyolefin, and aliphatic polyamide; and
one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers;
Contains
Concrete reinforcement.
Aspect 10
A part of the linear body contains the aliphatic resin fiber, and
Another part of the linear bodies contains the additional fiber.
10. The concrete reinforcement material according to claim 9.
<Aspect 11>
A part of the linear bodies is a thread formed by twisting the aliphatic resin fibers together or a string-like body formed by bundling the aliphatic resin fibers, and
Another part of the linear body is a thread formed by twisting the additional fibers together, or a string-like body formed by bundling the additional fibers.
11. The concrete reinforcement material according to claim 9 or 10.
<Aspect 12>
Aspect 12. The concrete reinforcement material of any one of aspects 9 to 11, wherein the additional fibers are aromatic resin fibers, and the aromatic resin fibers are aramid fibers.
<Aspect 13>
the linear members constituting the mesh body extend along a first direction, a second direction, and a third direction;
The first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°.
The concrete reinforcement material according to any one of the preceding aspects.
<Aspect 14>
the linear members constituting the mesh body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction,
The fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°,
The sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and intersect with the fourth direction and the fifth direction, respectively, at an angle of 40° to 50°.
The concrete reinforcement material according to any one of the preceding aspects.
<Aspect 15>
the linear members constituting the mesh body extend along a first direction, a second direction, and a third direction;
the first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°;
The linear body extending along the first direction includes the aliphatic resin fiber, and
The linear body extending along the second direction includes the additional fiber.
The concrete reinforcement material according to any one of aspects 9 to 12.
<Aspect 16>
the linear members constituting the mesh body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction,
The fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°,
the sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and intersect with the fourth direction and the fifth direction, respectively, at an angle of 40° to 50°;
The linear body extending along the fourth direction includes the aliphatic resin fiber, and
The linear body extending along the fifth direction includes the additional fiber.
The concrete reinforcement material according to any one of aspects 9 to 12.
Aspect 17
The concrete reinforcement material according to any one of claims 1 to 16, wherein the mesh body is formed by weaving the linear bodies together.
<Aspect 18>
The convex body separates the mesh body from the surface of a concrete molding form by a predetermined length when the concrete reinforcement is brought into contact with the formwork, and
The predetermined length is set so that when concrete is poured into the formwork, mortar in the concrete or cement paste in the concrete can penetrate between the formwork and the reticulate body.
The concrete reinforcement material according to any one of the preceding claims.
<Aspect 19>
A concrete reinforcement material according to any one of the preceding claims, wherein the convex bodies are mineral granules adhered to the reticulate body via an adhesive.
Aspect 20
A concrete structure having the concrete reinforcement according to any one of aspects 1 to 19, wherein the concrete reinforcement is embedded near a surface of the concrete structure along a surface direction of the surface.
Concrete structure.
<Aspect 21>
To provide a formwork for concrete casting;
Providing a concrete reinforcement material according to any one of aspects 1 to 19;
placing the concrete reinforcement along the inner surface of the formwork such that the convex portion of the concrete reinforcement contacts the bottom of the formwork, thereby forming a gap between the mesh of the concrete reinforcement and the bottom of the formwork; and pouring concrete into the formwork such that the concrete, the mortar in the concrete, and/or the cement paste in the concrete flows into the gap, thereby embedding the mesh in the concrete.
A method for manufacturing a concrete structure comprising:

The invention disclosed herein can provide a concrete reinforcing material with improved spalling resistance and safety.

Furthermore, the present disclosure can provide a concrete structure having such concrete reinforcement and a method for manufacturing the same.

FIG. 1 is a cross-sectional schematic diagram illustrating one embodiment of a concrete structure having concrete reinforcement according to the present disclosure. FIG. 2 is a schematic diagram for explaining an application example of a concrete structure having the concrete reinforcement according to the present disclosure. FIG. 3 is a top schematic diagram illustrating one embodiment of a concrete reinforcement material containing aliphatic resin fibers in accordance with the present disclosure. FIG. 4 is a top schematic diagram illustrating another embodiment of a concrete reinforcement material containing aliphatic resin fibers in accordance with the present disclosure. FIG. 5 is a top schematic diagram illustrating one embodiment of a concrete reinforcement material having aliphatic resin fibers and additional fibers in accordance with the present disclosure. FIG. 6 is a top schematic diagram illustrating another embodiment of a concrete reinforcement material having aliphatic resin fibers and additional fibers in accordance with the present disclosure. FIG. 7 is a schematic cross-sectional view showing some of the steps in one embodiment of a method for manufacturing a concrete structure according to the present disclosure.

Below, an embodiment of the invention according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present disclosure. The embodiments shown in the drawings are examples of the present disclosure, and do not limit the present disclosure.

<Concrete reinforcement material containing aliphatic resin fibers>
The concrete reinforcement material containing aliphatic resin fibers according to the present disclosure is
A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh-like body composed of linear bodies and protruding bodies distributed on a surface of the mesh-like body,
The convex body protrudes at least in a direction perpendicular to the surface direction of the mesh body,
The linear body contains aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and has a total fineness of 3,500 decitex to 50,000 decitex.

Conventional concrete reinforcing materials use fibers with high tensile strength and tensile modulus to compensate for the characteristic of concrete material, which is strong in compression but weak in tension. Concrete materials with such conventional reinforcing materials exhibit relatively strong resistance to deformation against external forces, but once the concrete material deforms, even at a relatively small level of deformation, concrete pieces and aggregates can peel off and fall, and the reinforcing material can be pulled out, resulting in the complete elimination of the reinforcing effect.

In response to this, the present inventors have discovered that the above-mentioned concrete reinforcing material according to the present disclosure can provide a concrete reinforcing material with improved spalling prevention and safety. In other words, the concrete reinforcing material according to the present disclosure can maintain the reinforcing effect and spalling prevention effect of the reinforcing material not only when the degree of deformation is small during the deformation process of the concrete material, but also when the degree of deformation is relatively large, and as a result, spalling prevention and high safety can be ensured during the deformation and destruction process of the concrete material.

Without intending to be limited by theory, the aliphatic resin fibers contained in the concrete reinforcing material according to the present disclosure have the same functionality when deformation is small compared to reinforcing fibers used in conventional reinforcing materials, and can retain their functionality as a reinforcing material even when deformation becomes relatively large. Therefore, it is believed that a concrete structure reinforced with the concrete reinforcing material according to the present disclosure can maintain its integrity, spalling resistance, and safety even after deformation and destruction have progressed to a certain extent.

A concrete reinforcing material containing the aliphatic resin fibers according to the present disclosure is embedded in concrete.

1 is a schematic cross-sectional view of a concrete structure 11 near a surface 18 having a concrete reinforcement material 10 containing an aliphatic resin fiber according to the present disclosure. In this concrete structure 11, the concrete reinforcement material 10 according to the present disclosure is embedded in concrete 17 along the surface 18 of the concrete structure 11. The concrete reinforcement material 10 has a mesh body composed of linear bodies 12 and granular bodies as convex bodies 14. The granular bodies as the convex bodies 14 protrude at least in a direction perpendicular to the surface direction of the mesh body. The mesh body of the concrete reinforcement material 10 is separated from the surface 18 by a distance corresponding to the particle size of the granular bodies. The mortar or cement paste in the concrete 17 is wrapped around between the surface 18 of the concrete structure 11 and the mesh body of the concrete reinforcement material 10, and the surface 18 of the concrete structure 11 is finished with a good appearance. In the embodiment of FIG. 1, a part of the convex body 14 is exposed on the surface 18 of the concrete. The concrete structure 11 in FIG. 1 also has reinforcing bars 16 arranged in two perpendicular directions, and a cover portion 15.

The concrete structure 11 in FIG. 1 includes the concrete reinforcement material 10 according to the present disclosure, and therefore is able to prevent parts of the cover portion 15 from becoming concrete fragments and falling off, even if the concrete structure is subjected to a relatively large deformation due to an external force.

In addition, in the concrete structure 11 of Figure 1, the concrete reinforcement 10 is placed near the surface, so even if cracks occur on the concrete surface due to alkali-aggregate reaction or corrosion of the reinforcing bars, the crack width is prevented from expanding.

Figure 2 is a schematic diagram for explaining an application example of a concrete structure according to the present disclosure. Figure 2 shows a prestressed concrete box girder 20, a lower deck 21, a web 22, and an overhanging portion 23 of the upper deck. The concrete reinforcement material 1 according to the present disclosure can be embedded, for example, near the underside of the lower deck 21, the outer surface of the web 22, and the underside of the overhanging portion 23 of the upper deck.

The concrete reinforcement material according to the present disclosure is composed of a mesh body made up of linear bodies and a convex body. The convex body is disposed on the linear body that constitutes the mesh body.

The concrete reinforcement material according to the present disclosure can be formed, for example, by impregnating a mesh formed by weaving linear bodies into a net with epoxy resin as an adhesive, and then adhering, for example, silica sand as a convex body in a uniformly distributed manner.

Figure 3 is a schematic plan view showing one embodiment of a concrete reinforcement material according to the present disclosure. In the concrete reinforcement material 30 shown in Figure 3, a network composed of linear bodies 32 has granular bodies 34 as convex bodies distributed on the linear bodies 32.

Figure 4 is a schematic plan view showing another embodiment of a concrete reinforcement material according to the present disclosure. In the concrete reinforcement material 40 shown in Figure 4, a network composed of linear bodies 42 has granular bodies 44 as convex bodies distributed on the linear bodies 42.

<Reticulum>
The mesh-like body of the concrete reinforcement material according to the present disclosure is composed of linear bodies.

The mesh may be formed by weaving together linear bodies. The spacing between the linear bodies that make up the mesh (mesh size) may be 1 mm to 500 mm, or 5 mm to 200 mm, 10 mm to 100 mm, or 15 to 60 mm.

In a preferred embodiment of the present disclosure, the linear bodies constituting the mesh body extend along a first direction, a second direction, and a third direction that intersect with each other at an angle of 55° to 65°. Particularly preferably, the first direction, the second direction, and the third direction intersect with each other at an angle of 57° to 63°, 58° to 62°, 59° to 61°, 59.5° to 60.5°, or 59.9° to 60.1°.

The concrete reinforcement mesh in FIG. 3 is formed by interweaving linear bodies 32 arranged in three directions that intersect at approximately 60° to each other.

When the linear bodies constituting the mesh extend along the first, second, and third directions, and the first, second, and third directions intersect at angles of 55 to 65 degrees, large deformation is restrained even if tensile forces act in the three directions in which the linear bodies are arranged. Therefore, the difference in the amount of deformation due to direction is smaller compared to when the linear bodies are arranged in only two mutually perpendicular directions. In addition, when manufacturing a concrete structure having concrete reinforcement, the concrete reinforcement can be brought into contact with the inner surface of the formwork while applying tensile force, making it easier to fix it without causing wrinkles, etc.

In another preferred embodiment according to the present disclosure, in the concrete reinforcement material, the linear bodies constituting the network extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction,
The fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°,
The sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and also intersect with the fourth direction and the fifth direction, respectively, at an angle of 40° to 50°.

Particularly preferably,
the fourth direction and the fifth direction cross each other at an angle of 87° to 93°, 89° to 91°, 89.5° to 90.5°, or 89.9° to 90.1°; and/or
The sixth direction and the seventh direction intersect with each other at an angle of 87° to 93°, 89° to 91°, 89.5° to 90.5°, or 89.9° to 90.1°, and intersect with the fourth direction and/or the fifth direction at an angle of 42 to 48°, 44 to 46°, 44.5 to 45.5°, or 44.9 to 45.1°, respectively.

The concrete reinforcement mesh in FIG. 4 has a structure in which the linear bodies 42 are woven in four directions. That is, the mesh is formed by arranging the linear bodies 42 in two mutually perpendicular directions and in two additional directions that intersect the two directions at 45° angles.

When the linear bodies constituting the net-like body extend along the fourth, fifth, sixth, and seventh directions, the fourth and fifth directions intersect at an angle of 85 to 95 degrees, and the sixth and seventh directions intersect at an angle of 85 to 95 degrees and at an angle of 40 to 50 degrees with the fourth and/or fifth directions, even if tensile forces are applied in directions perpendicular to each other, no large deformation occurs in either direction. In addition, deformation is also restricted in oblique directions, making it almost isotropic. Therefore, in the manufacturing process of concrete reinforcement, the work of winding up the woven net-like body, the work of supporting the net-like body in an unfolded state and impregnating it with adhesive, and the work of adhering granular bodies to the net-like body are remarkably facilitated. In addition, when manufacturing a concrete structure having concrete reinforcement, the work of arranging the concrete reinforcement along a formwork is also facilitated.

(Linear body)
The linear body contains aliphatic resin fibers formed from one or more selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide.

As the aliphatic resin fiber contained in the linear body, polyvinyl alcohol (PVA) and polyolefin are suitable, and a mixture of two or more of these can also be used. Polyvinyl alcohol includes those that have been made water insoluble by acetalization. Polyolefins include polyethylene, polypropylene, and polymethylpentene. An example of an aliphatic polyamide is nylon 6.

The total fineness of the linear bodies constituting the concrete reinforcing material containing aliphatic resin fibers is 3,500 decitex to 50,000 decitex. With a total fineness of 3,500 decitex or more, compared to the reinforcing fibers used in conventional reinforcing materials, it has the same function when deformation is small, and can maintain its function as a reinforcing material even if deformation becomes relatively large. Furthermore, with a total fineness of 50,000 decitex or less, when manufacturing a concrete structure, a mesh size large enough for fresh concrete to easily pass through the mesh of the reticulated body can be ensured, and as a result, a concrete structure can be obtained in which the concrete reinforcing material is well embedded in the concrete.

To determine the total fineness of the linear body, the mass of 100 m of the linear body wound up is measured using a measuring machine, and the measured mass is multiplied by 100 to calculate the fineness (dtex) per 10,000 m, which can be used as the total fineness of the linear body.

Preferably, the total fineness of the linear bodies constituting the concrete reinforcing material containing aliphatic resin fibers may be 4,000 decitex or more, 5,000 decitex or more, 6,000 decitex or more, 7,000 decitex or more, or 8,000 decitex or more, and/or 40,000 decitex or less, 30,000 decitex or less, 20,000 decitex or less, or 15,000 decitex or less.

There are no particular limitations on the convergence state and the alignment state of the linear body, and it may be twisted fibers, aligned fibers, or a resin molding. The fibers (bundles) constituting the linear body may be folded over, aligned in parallel, aligned without gaps or folded over, and/or aligned with gaps or folded over.

Preferably, the linear bodies are threads formed by twisting the above-mentioned aliphatic resin fibers together, or string-like bodies formed by bundling the above-mentioned aliphatic resin fibers. In a concrete reinforcing material having a mesh made up of linear bodies that are threads or string-like bodies, the surface area of the linear bodies that make up the mesh is relatively large, and as a result, a sufficient adhesion area between the mesh and the convex body can be ensured. In addition, such a mesh has a reduced risk of deterioration due to corrosion, and can be manufactured at low cost.

The string-like body may be produced, for example, by aligning fibers of 100 to 10,000 filaments or 500 to 5,000 filaments and bundling the aligned fibers into a string using a binder resin.

(Convex body)
The concrete reinforcement material according to the present disclosure has convex bodies distributed on the surface of a mesh body, and these convex bodies protrude at least in a direction perpendicular to the plane direction of the mesh body. In the concrete reinforcement material 10 of Fig. 1, granular bodies as convex bodies 14 are distributed on the surface of a mesh body formed by linear bodies 12, and protrude at least in a direction perpendicular to the direction in which the plane of the mesh body extends.

By having the concrete reinforcement have such convex bodies, when manufacturing a concrete structure having the concrete reinforcement, the reticulate body can be separated from the formwork by a distance according to the size of the convex bodies. Therefore, it is possible to obtain a concrete structure having the concrete reinforcement embedded at a fixed distance from the surface of the concrete structure.

When concrete reinforcement is embedded near the surface of a concrete structure, it resists the tensile force acting near the surface of the concrete structure, dispersing cracks on the concrete surface and reducing the width of the cracks. Furthermore, even if cracks progress due to deterioration of the concrete, pieces of concrete are prevented from falling off because the concrete reinforcement is placed continuously near the surface.

Preferably, the convex body separates the surface of the mesh body from the surface of the formwork by a predetermined length when the concrete reinforcement is brought into contact with the formwork for casting concrete, and the predetermined length is set to an extent that the mortar in the concrete or the cement paste in the concrete penetrates between the formwork and the mesh body when concrete is poured into the formwork. When a convex body that satisfies this condition is used, the mesh body is not exposed on the surface of the concrete member, resulting in a particularly good finish.

For the convex body, the above-mentioned "predetermined length" is in the range of 1 μm to 100 mm, and preferably 10 μm to 50 mm, 100 μm to 10 mm, 1 mm to 5 mm, or 2 mm to 3 mm.

The shape of the convex body is not particularly limited, and may be spherical, scaly, or fibrous, or may be amorphous or spherical. In the context of this application, "irregular" means that the convex body is not formed by a mold or the like.

Preferably, the convex body is a mineral granule.

As the mineral granules, silica sand and/or river sand can be used, but glass and/or metal particles can also be used. It can also be clay and/or coal ash that has been kneaded, granulated and fired, or synthetic resin molded into granules.

The particle size of the mineral granules is not particularly limited, but can be set appropriately depending on the shape, dimensions, and/or application of the concrete structure in which the concrete reinforcement is used. The particle size of the mineral granules may be, for example, 0.1 mm to 100 mm, 0.5 mm to 25 mm, 1 mm to 10 mm, 1.5 mm to 5 mm, or 2 mm to 3 mm.

The particle size of the granular material can be measured by calculating the average equivalent circle diameter of 100 randomly selected granular materials in an image obtained using an optical microscope, etc.

The convex body is preferably attached to the mesh body via an adhesive. The adhesive for adhering the convex body to the mesh body is not particularly limited, but is preferably insoluble in water and is particularly preferably one with strong adhesive power, such as an epoxy resin. The epoxy resin provides particularly strong adhesion between the convex body and the mesh body when cured.

The convex body may be formed by adhering a member made of metal, ceramic, or synthetic resin, or sand, gravel, etc., to the mesh body, or the convex body may be formed by enmeshing uncured synthetic resin with the mesh body and molding it into a convex shape.

<Concrete reinforcement material having aliphatic resin fiber and additional fiber>
The present disclosure also includes a concrete reinforcement material containing aliphatic resin fibers and additional fibers, as follows:
A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh-like body composed of linear bodies and protruding bodies distributed on a surface of the mesh-like body,
The convex body protrudes at least in a direction perpendicular to the surface direction of the mesh body,
The linear body is
An aliphatic resin fiber formed from one or more synthetic resins selected from polyvinyl alcohol, polyolefin, and aliphatic polyamide; and
one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers;
Contains
Concrete reinforcement.

Conventional concrete reinforcing materials use fibers with high tensile strength and tensile modulus of elasticity to compensate for the characteristic of concrete material, which is strong in compression but weak in tension. As a result, while concrete materials with conventional reinforcing materials exhibit relatively strong resistance to deformation against external forces, once the concrete begins to deform, even when the degree of deformation is relatively small, concrete pieces and aggregates can peel off and fall, and the reinforcing materials can be pulled out, resulting in the complete elimination of the reinforcing effect.

In response to this, the present inventors have discovered that a concrete reinforcing material containing the aliphatic resin fibers and additional fibers according to the present disclosure can provide a concrete reinforcing material with improved spalling prevention and safety. In other words, a concrete reinforcing material containing the aliphatic resin fibers and additional fibers according to the present disclosure can maintain the reinforcing effect and spalling prevention effect of the reinforcing material not only when the degree of deformation is small during the deformation process of the concrete material, but also when the degree of deformation is relatively large, and as a result, spalling prevention and high safety can be ensured during the deformation and destruction process of the concrete material.

Without intending to be limited by theory, the above-mentioned aliphatic resin fibers have the same functionality when deformation is small compared to reinforcing fibers that have been used in conventional reinforcing materials, and can retain their functionality as a reinforcing material even when deformation becomes relatively large. Therefore, it is believed that a concrete structure reinforced with the concrete reinforcing material according to the present disclosure can maintain its ability to prevent concrete fragments and the like from falling off even after it has been deformed or destroyed to a certain extent.

In addition, the concrete reinforcement material containing the aliphatic resin fiber and additional fibers according to the present disclosure has one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers, and therefore has further improved resistance (resistance and strength at the beginning of deformation) when the degree of deformation of the concrete is relatively small.

Furthermore, in the concrete reinforcing material containing the aliphatic resin fibers and additional fibers according to the present disclosure, the balance between resistance to deformation and strength, and prevention of spalling and safety during deformation and destruction can be set to a desired degree by selecting the ratio of the aliphatic resin fibers to the additional fibers. This is particularly advantageous in obtaining an optimal reinforcing material for various applications.

<Reticulum>
The concrete reinforcement material containing aliphatic resin fibers and additional fibers includes a network composed of linear bodies. With regard to the network, reference may be made to the above description of the concrete reinforcement material having aliphatic resin fibers, except that the network contains additional fibers.

Preferably, the network of concrete reinforcement containing aliphatic resin fibers and additional fibers is formed by interweaving linear bodies.

<Linear body>
In the concrete reinforcement material containing aliphatic resin fibers and additional fibers, the linear bodies are
An aliphatic resin fiber formed from one or more synthetic resins selected from polyvinyl alcohol, polyolefin, and aliphatic polyamide; and
one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers;
Contains:

(Aliphatic resin fiber)
In a concrete reinforcing material containing aliphatic resin fibers and additional fibers, for the aliphatic resin fibers contained in the linear bodies, reference can be made to the above description regarding the concrete reinforcing material having aliphatic resin fibers.

(Additional Fiber)
The additional fiber contained in the concrete reinforcement material having the aliphatic resin fiber and the additional fiber is one or more fibers selected from metal fiber, aromatic resin fiber, carbon fiber, glass fiber, and basalt fiber. The additional fiber is preferably a fiber having a relatively high tensile strength and/or tensile modulus. The metal fiber may be, for example, boron fiber, titanium fiber, and/or steel fiber. The aromatic resin fiber may be, for example, a fiber formed from aramid, PBO (polyparaphenylene benzbisoxazole), and/or polyarylate.

Because of their proven track record and ease of handling, it is preferable for the additional fibers to be aromatic resin fibers, and aramid fibers are particularly preferable as aromatic resin fibers.

In a concrete reinforcement material containing aliphatic resin fibers and additional fibers, some of the linear bodies may contain aliphatic resin fibers, and other parts of the linear bodies may contain the additional fibers.

Preferably, in a concrete reinforcing material containing aliphatic resin fibers and additional fibers, the linear bodies constituting the network extend along a first direction, a second direction, and a third direction,
the first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°;
the linear body extending along the first direction includes an aliphatic resin fiber,
The linear bodies extending along the second direction include additional fibers, and the linear bodies extending along the third direction optionally include aliphatic resin fibers or additional fibers.

Figure 5 is a plan schematic diagram showing one preferred embodiment of a concrete reinforcement material containing aliphatic resin fibers and additional fibers according to the present disclosure. In the concrete reinforcement material 50 containing aliphatic resin fibers and additional fibers shown in Figure 5, a network composed of linear bodies 52 has convex bodies 54 distributed on the linear bodies 52. The network in Figure 5 is formed by arranging and weaving the linear bodies 52 in three directions that are approximately intersecting each other. The linear bodies 52a (black lines) extending along the direction D1 contain the aliphatic resin fibers according to the present disclosure, and the linear bodies 52b and 52c extending along the directions D2 and D3 contain the additional fibers (white lines) according to the present disclosure.

Preferably, in a concrete reinforcement material containing aliphatic resin fibers and additional fibers,
The linear members constituting the mesh body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction,
The fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°,
the sixth direction and the seventh direction intersect with each other at an angle of 85° to 95° and intersect with the fourth direction and the fifth direction, respectively, at an angle of 40° to 50°;
the linear body extending along the fourth direction includes an aliphatic resin fiber,
The linear bodies extending along the fifth direction include additional fibers, and the linear bodies extending along the sixth and seventh directions each optionally include aliphatic resin fibers or additional fibers.

Figure 6 is a plan schematic diagram showing another preferred embodiment of a concrete reinforcement material containing aliphatic resin fibers and additional fibers according to the present disclosure. In the concrete reinforcement material 60 containing aliphatic resin fibers and additional fibers shown in Figure 6, a network composed of linear bodies 62 has convex bodies 64 distributed on the linear bodies 62. The network in Figure 6 is formed by arranging the linear bodies 62 in two directions perpendicular to each other and two additional directions intersecting the linear bodies 62 at an angle of 45°. In the concrete reinforcement material 60 shown in Figure 6, the linear body 62a (shown as a black line) extending along the direction D4 contains the aliphatic resin fibers according to the present disclosure, and the linear bodies 62b, 62c, and 62d extending along the directions D5, D6, and D7 contain the additional fibers (shown as a white line) according to the present disclosure.

In a concrete reinforcing network having aliphatic resin fibers and additional fibers, the ratio of linear bodies containing aliphatic resin fibers to linear bodies containing additional fibers can be determined by taking into consideration the required reinforcing performance, i.e., whether emphasis is placed on the resistance and strength of the reinforced concrete structure at the beginning of deformation, or on the prevention of spalling and safety during the deformation and destruction process, and striking a balance between the two.

In a concrete reinforcement material containing aliphatic resin fibers and additional fibers, the total fineness of the linear bodies containing the aliphatic resin fibers may be 3,500 dtex to 50,000 dtex. Preferably, the total fineness of the linear bodies may be 4,000 dtex or more, 5,000 dtex or more, 6,000 dtex or more, 7,000 dtex or more, or 8,000 dtex or more, and/or 40,000 dtex or less, 30,000 dtex or less, 20,000 dtex or less, or 15,000 dtex or less.

In a concrete reinforcement material containing aliphatic resin fibers and additional fibers, the total fineness of the linear bodies containing the additional fibers is not particularly limited, but may be 500 dtex to 50,000 dtex. Preferably, the total fineness of the linear bodies may be 1,000 dtex or more, 2,000 dtex or more, 3,000 dtex or more, 4,000 dtex or more, or 5,000 dtex or more, and/or 30,000 dtex or less, 15,000 dtex or less, 10,000 dtex or less, or 7,500 dtex or less.

Preferably, in the concrete reinforcement material containing aliphatic resin fibers and additional fibers,
A part of the linear body is a thread made by twisting aliphatic resin fibers together or a string-like body made by bundling aliphatic resin fibers, and
Another part of the linear bodies is a thread made by twisting together additional fibers, or a string made by bundling additional fibers.

When metal wires are used as additional fibers, various metal wires, such as steel wires, can be used as long as they have sufficient strength. For example, stainless steel and/or titanium, which will not corrode even if the concrete is neutralized, can be used as the metal wire.

<Convex body>
Regarding the convex body contained in the concrete reinforcing material containing aliphatic resin fibers and additional fibers, the above description regarding the convex body contained in the concrete reinforcing material containing aliphatic resin fibers can be referred to. When a metal wire is used as the additional fiber, the convex body can be formed by bending a part of the metal wire contained in the linear body into a convex shape.

<Concrete structure>
The present disclosure includes the following concrete structures:
A concrete reinforcement material according to the present disclosure,
Concrete reinforcement is embedded near the surface of the concrete structure along the surface direction.

An embodiment of the concrete structure according to the present disclosure is as described above with reference to FIG. 1. The concrete reinforcement and the concrete are preferably intimately integrated.

The concrete structure according to the present disclosure has improved spalling resistance and safety because it contains the concrete reinforcement material according to the present disclosure.

When the concrete structure according to the present disclosure has a concrete reinforcing material containing aliphatic resin fibers as the concrete reinforcing material according to the present disclosure, it is possible to maintain spalling prevention properties even after being deformed or destroyed to a certain extent.

When the concrete structure according to the present disclosure has a concrete reinforcing material containing aliphatic resin fibers and additional fibers as the concrete reinforcing material according to the present disclosure, spalling prevention properties can be maintained even after a certain degree of deformation or destruction, and resistance (resistance and strength at the beginning of deformation) is further improved when the degree of deformation of the concrete is relatively small.

Furthermore, when the concrete structure according to the present disclosure has a concrete reinforcing material containing aliphatic resin fibers and additional fibers as the concrete reinforcing material according to the present disclosure, by selecting the ratio of the contained aliphatic resin fibers and additional fibers, it is possible to provide a concrete structure in which the balance between resistance and strength at the beginning of deformation and prevention of spalling and safety during the deformation and destruction process is optimized according to the application.

In the concrete structure according to the present disclosure, it is preferable that the concrete reinforcement is in close contact with the concrete constituting the concrete structure. The concrete constituting the concrete structure according to the present disclosure is not particularly limited, and general concrete used for civil engineering structures can be used.

The size of the concrete structure according to the present disclosure is not particularly limited. The shape of the concrete structure according to the present disclosure is also not particularly limited, and may be, for example, flat.

Preferably, the concrete structure according to the present disclosure exhibits a resistance of 0.3 kN or more at a displacement of 40 mm and/or a resistance of 0.2 kN or more at a displacement of 50 mm when measured according to a push-out test based on NEXCO Test Method 424-2011 "Push-out test method for preventing spalling" (4.1 When continuous fiber sheets are embedded near the concrete surface).

More preferably, the concrete structure according to the present disclosure exhibits a resistance of 0.5 kN or more, 1.0 kN or more, 1.5 kN or more, or 2.0 kN or more at a displacement of 40 mm when measured according to the above-mentioned push-out test, and/or exhibits a resistance of 0.3 kN or more, 0.5 kN or more, 1.0 kN or more, 1.5 kN or more, or 2.0 kN or more at a displacement of 50 mm.

Preferably, the concrete structure according to the present disclosure exhibits a resistance of 0.5 kN or more, 1.0 kN or more, 1.5 kN or more, or 2.0 kN or more at a displacement of 10 mm when measured according to the above-mentioned push-out test, and/or exhibits a resistance of 0.8 kN or more, 1.5 kN or more, 2.5 kN or more, 3.0 kN or more, or 3.5 kN or more at a displacement of 20 mm, and/or exhibits a resistance of 1.5 kN or more, 2.5 kN or more, 3.5 kN or more, 4.0 kN or more, or 4.5 kN or more at a displacement of 30 mm.

The concrete structure according to the present disclosure can be manufactured, for example, by the manufacturing method according to the present disclosure shown below.

<Manufacturing method of concrete structure>
The present disclosure includes a method for producing a concrete structure comprising:
Providing a formwork for concrete casting (formwork providing step);
Providing a concrete reinforcement material according to the present disclosure (reinforcement material providing step);
Placing the concrete reinforcement along the inner surface of the formwork so that the convex portion of the concrete reinforcement contacts the bottom of the formwork, thereby forming a gap between the mesh of the concrete reinforcement and the bottom of the formwork (reinforcement placement step); and pouring the concrete into the formwork so that the concrete, the mortar in the concrete, and/or the cement paste in the concrete flows into the gap, thereby embedding the mesh in the concrete (casting step).
Includes.

According to the manufacturing method of the present disclosure, the concrete reinforcement is arranged along the inner surface of the formwork so that the convex body of the concrete reinforcement contacts the bottom of the formwork. As a result, the concrete reinforcement is supported at a position a certain distance away from the inner surface of the formwork, and a gap is formed between the mesh body of the concrete reinforcement and the inner surface of the formwork. Therefore, when the concrete is poured, the mortar and/or cement paste in the concrete flows into the gap, and the concrete reinforcement is well embedded under the surface of the concrete structure. Therefore, according to the manufacturing method of the present disclosure, the mesh body is not exposed on the surface of the concrete member, and a good finish is obtained. In addition, the mesh body is embedded in the concrete, which prevents deterioration of the mesh body. Furthermore, since the mesh body can be easily arranged, it is possible to form a concrete structure that is reinforced near the surface and has a good appearance at a low cost.

Furthermore, according to the manufacturing method of the present disclosure, it is possible to manufacture a concrete structure having the concrete reinforcement material of the present disclosure, thereby providing a concrete structure with improved spalling prevention and safety.

<Formwork provision process>
In the formwork providing step in the method for manufacturing a concrete structure of the present disclosure, a formwork for concrete molding is provided. The formwork is not particularly limited, and any known formwork used for concrete molding can be used. For example, the formwork may be a formwork assembled from plywood and/or battens. The shape of the formwork is not particularly limited, and can be appropriately set according to the shape of the concrete structure to be manufactured.

<Reinforcement material provision process>
In the reinforcement material providing step in the method for producing a concrete structure according to the present disclosure, a concrete reinforcement material according to the present disclosure is provided. For the concrete reinforcement material according to the present disclosure, the above description can be referred to.

In the reinforcement providing process, the size of the concrete reinforcement can be adjusted to match the size of the formwork. For example, the size of the concrete reinforcement can be adjusted by cutting the concrete reinforcement.

<Reinforcement material placement process>
In the reinforcement placement step in the concrete structure manufacturing method of the present disclosure, the concrete reinforcement is placed along the inner surface of the formwork so that the convex body of the concrete reinforcement contacts the bottom of the formwork, thereby forming a gap between the mesh body of the concrete reinforcement and the bottom of the formwork.

In the reinforcement placement process, for example, the concrete reinforcement may be placed along the inner surface of the formwork corresponding to the surface of the concrete structure that requires surface reinforcement, so that it is in contact with the formwork. In addition, the concrete reinforcement placed in the reinforcement placement process may be one in which the adhesion between the mesh body and the convex body is not complete, but it is preferable that the adhesive applied to the mesh body has hardened and has rigidity.

Preferably, in the reinforcement placement step, the concrete reinforcement is temporarily fixed to the formwork. When the concrete reinforcement is temporarily fixed to the formwork, it can be supported in a predetermined position by simply temporarily fixing the concrete reinforcement to the formwork at several points. Temporary fixing can be performed using known fixing devices.

In the reinforcement placement process, the concrete reinforcement may be temporarily fixed to the formwork with an adhesive. In this case, it is preferable to select an adhesive that is easily removed when removing the formwork and that does not stain the surface of the concrete structure.

(Assembly of rebar)
The manufacturing method according to the present disclosure may further include a rebar assembly step of assembling rebars in a formwork. The rebar assembly step is preferably performed after the reinforcing material arrangement step. In the rebar assembly step, rebars that have been assembled in advance in a basket shape in a factory or an assembly yard may be installed in a predetermined position in the formwork.

The position of the rebar may be fixed relative to the formwork to ensure the installation dimensions and cover thickness of the rebar. For example, the position of the rebar relative to the formwork can be fixed by passing the longitudinal rebar through the formwork and fixing it to the orthogonal rebar using tie wires.

After the reinforcing bar assembly process, a mortar spacer attachment process can be further carried out. In the mortar spacer attachment process, a mortar spacer is attached to the reinforcing bar and is brought into contact with the concrete reinforcement material. By attaching the mortar spacer, it is possible to maintain the distance between the reinforcing bar and the formwork.

<Pouring process>
In the casting step in the manufacturing method of a concrete structure of the present disclosure, concrete is cast into a formwork so that the concrete, mortar in the concrete, and/or cement paste in the concrete flow into the above-mentioned gaps, thereby embedding the reticulate body in the concrete. Preferably, in the casting step, concrete is cast into a formwork so that the mortar in the concrete and/or cement paste in the concrete flow into the above-mentioned gaps, thereby embedding the reticulate body in the concrete.

The method of pouring the concrete is not particularly limited, and for example, the concrete may be poured by dropping it into the formwork using a shovel.

During the casting process, a vibrator or the like can be used to ensure that the mortar of the concrete or the cement paste is sufficiently distributed between the concrete reinforcement and the formwork. For example, compaction can be performed using an internal vibrator.

(Curing process)
Preferably, after the casting step, sufficient curing is performed, and then the concrete structure is removed from the formwork. For example, after the casting step, wet curing is performed at a temperature of 15 to 25° C. for 5 to 20 days, and then the concrete structure may be removed from the formwork.

Figure 7 shows a part of the manufacturing process in one embodiment of the method for manufacturing a concrete structure according to the present disclosure. In the method shown in Figure 7, a form 78 (part of which is shown in Figure 7) is first assembled in a predetermined position. Then, as shown in Figure 7, concrete reinforcement 70 is placed along the bottom 78a of the form 78 corresponding to the surface of the concrete structure on the side that is intended to be reinforced, so as to be in contact with the bottom 78a. Then, optionally, reinforcing bars 76 are assembled in the form 78. Then, optionally, mortar spacers 79 are attached to the reinforcing bars 76 and abutted against the concrete reinforcement 70. Then, concrete (not shown) is poured into the form 78.

According to the manufacturing method disclosed herein, a concrete structure having reinforcement near the concrete surface can be easily formed simply by placing the concrete reinforcement 70 in contact with the formwork 78, resulting in a finished concrete structure with a good appearance without the reinforcement being exposed on the surface.

The present invention will be specifically explained below using examples, but the present invention is not limited to these specifically shown examples.

Example 1
As described below, a concrete structure (concrete specimen) having the concrete reinforcing material according to Example 1 was manufactured, and performance evaluation was carried out by a push-out test.

<Production of concrete specimens>
The concrete specimens were flat plates measuring 400 mm wide, 600 mm long, and 100 mm thick. Three concrete specimens were prepared per standard in accordance with NEXCO Test Method 424-2011, “Push-out Test Method for Anti-Flap Test” (4.1 Continuous Fiber Sheets Embedded Near the Concrete Surface).

(Formwork)
The formwork used to manufacture the concrete specimens was made of concrete formwork plywood and battens. To ensure the installation dimensions and cover thickness of the reinforcing bars, the longitudinal reinforcing bars were passed through the formwork and fixed in place using orthogonal reinforcing bars and tie wires.

(Reticulated body)
The linear members constituting the mesh of the concrete reinforcing material (continuous fiber sheet) according to Example 1 were polyvinyl alcohol (PVA) fiber filaments (manufactured by Kuraray Co., Ltd.) that were aligned and bound linearly with a binder resin, and had a total fineness of 10,640 dx. The linear members were arranged in three directions crossing each other at an angle of approximately 60° and woven together to form a mesh. The spacing between the threads (mesh size) of the mesh was 15 to 60 mm.

(Convex body)
As the convex bodies of the concrete reinforcing material according to Example 1, silica sand having a particle size of 2 to 3 mm was used.
(Manufacturing of concrete reinforcement materials)
The above-mentioned mesh-like body was impregnated with liquid uncured epoxy resin as an adhesive. The mesh-like body was then pulled out of the impregnation liquid, and the above-mentioned silica sand as a convex body was pressed against and bonded to the mesh-like body. The adhesive was then cured, thereby producing the concrete reinforcing material according to Example 1 in which the silica sand was distributed in the mesh-like body.

(Arrangement of reinforcement materials)
The concrete reinforcement material was cut to a size of 400 mm x 400 mm, placed inside the formwork with the silica sand surface facing the formwork, and fixed in place by driving in special fasteners.

(Pouring)
The concrete used for pouring was a general mix for civil engineering structures (JIS A 5308 (ready mixed concrete)). The concrete was gently dropped into the formwork using a shovel, and compacted using an internal vibrator without touching the reinforcing bars, and then the concrete was poured.

When the bleeding had subsided, I used a wooden trowel and a metal trowel to smooth out the top surface.

After the concrete was poured, the concrete was cured indoors at a temperature of 20 degrees Celsius until it was 10 days old. The formwork was then removed, and the concrete was cured in the air indoors at a temperature of about 23 degrees Celsius. During this time, in preparation for the push-out test, a core was drilled from the casting surface to a diameter of 100 mm and a depth of 80±3 mm using a wet diamond core drill.

After core drilling, the concrete specimens were immediately moved into a room at room temperature of 23±2 degrees Celsius and left to rest until just before testing (after 48 hours or more had passed).

<Push-out test>
For the concrete structure according to Example 1, a push-out test was carried out based on NEXCO Test Method 424-2011 "Push-out test method for preventing spalling" (4.1 When a continuous fiber sheet is embedded near the concrete surface).

The specific procedure for the push-out test is as follows:
1) Concrete specimens were grouped into sets of three.
2) The concrete specimen was placed on a stand and a steel anvil with a diameter of 100 mm and a thickness of 55 mm was placed between the ball seats so that a load was applied evenly and vertically to the center of the core.
3) The gap between the ball seat and the steel anvil was minimized to a position where no load was applied, and the displacement was adjusted to zero.
4) The loading speed was the crosshead speed of the testing machine, which was 1 mm/min from a displacement of 0 (zero) mm until the concrete in the core was destroyed, and then 5 mm/min until the end of the test, and the load and displacement were measured.
5) The loading was stopped every 10 mm of displacement and the area of delamination was marked.
6) If the final load-bearing capacity was confirmed at a displacement of 30 mm, the test was terminated, and if it was determined that the specimen had further load-bearing capacity, the test was continued up to a displacement of 40 mm or 50 mm to confirm the anti-peeling performance.
7) Based on the load and displacement measurement data, the maximum load with a displacement of 10 mm or more was determined.
8) From the data obtained for each of the three concrete specimens, the average value of the maximum load with a displacement of 10 mm or more was calculated and used as the test value.

The results of the push-out test performed on Example 1 are shown in Table 1 below.

Example 2
A concrete structure according to Example 2 was prepared in the same manner as in Example 1, except that the total fineness of the linear bodies was set to 6,650 decitex, and a push-out test was carried out. The results are shown in Table 1 below.

Example 3
A concrete structure according to Example 3 was prepared in the same manner as in Example 1, except that linear bodies made of polyethylene (PE) fibers were used instead of linear bodies made of PVA fibers and the total fineness was set to 6,600 dtex, and a push-out test was carried out. The results are shown in Table 1 below.

Example 4
A concrete structure according to Example 4 was prepared in the same manner as in Example 1, except that linear bodies made of polypropylene (PP) fibers (manufactured by Mitsubishi Rayon Co., Ltd.) were used instead of linear bodies made of PVA fibers and the total fineness was set to 10,020 dtex, and a push-out test was carried out. The results are shown in Table 1 below.

Example 5
A concrete structure according to Example 5 was produced in the same manner as in Example 1, except that linear bodies made of polymethylpentene (PMP) fibers (produced by melt spinning a resin manufactured by Mitsui Chemicals, Inc.) were used instead of linear bodies made of PVA fibers, and the total fineness was set to 10,000 dtex, and a push-out test was carried out. The results are shown in Table 1 below.

Example 6
A concrete structure according to Example 6 was produced in the same manner as in Example 1, except that filaments made of nylon 6 (PA) (produced by melt spinning nylon 6 resin manufactured by Ube Industries, Ltd.) were used instead of filaments made of PVA fibers, and the total fineness was set to 10,000 dtex, and a push-out test was carried out. The results are shown in Table 1 below.

Example 7
A concrete structure according to Example 7 was prepared in the same manner as in Example 1, except that the total fineness of the linear bodies formed from the PVA fibers was set to 3990 decitex, and a push-out test was carried out. The results are shown in Table 1 below.

Comparative Example 1
A concrete structure according to Comparative Example 1 was prepared in the same manner as in Example 1, except that linear bodies made of para-type wholly aromatic polyamide fiber (TN, "Technora (registered trademark)" manufactured by Teijin Limited) were used instead of linear bodies made of PVA fiber, and the total fineness was set to 6680 dtex, and a push-out test was carried out. The results are shown in Tables 1 and 2 below.

Comparative Example 2
A concrete structure according to Comparative Example 2 was prepared in the same manner as in Example 1, except that linear bodies made of para-type wholly aromatic polyamide fiber (TN, "Technora (registered trademark)" manufactured by Teijin Limited) were used instead of linear bodies made of PVA fiber, and the total fineness was set to 3,340 decitex, and a push-out test was carried out. The results are shown in Tables 1 and 2 below.

Comparative Example 3
A concrete structure according to Comparative Example 3 was prepared in the same manner as in Example 1, except that the total fineness of the linear bodies formed from the PVA fibers was set to 3,300 decitex, and a push-out test was carried out. The results are shown in Table 1 below.

As can be seen from Table 1, the concrete structures of Examples 1 to 7, which contain PVA fibers, PE fibers, PP fibers, PMP fibers, or PA fibers and have concrete reinforcement with a total fineness of 3500 or more, exhibit relatively high resistance even when the displacement is relatively large (when the displacement is 40 mm or 50 mm).

In contrast, as can be seen from Table 1, the concrete structures of Comparative Example 1 and Comparative Example 2, which have concrete reinforcement made of TN fibers, lose their resistance when the displacement is relatively large (when the displacement is 40 mm or 50 mm).

Also, as can be seen in Table 1, even if PVA fibers are included, when the total fineness is 3,500 decitex or less (as in the case of the concrete structure of Comparative Example 3), the resistance is lower than in Examples 1 to 7.

Examples 8 and 9
In Examples 8 and 9, experiments were conducted using linear bodies made of aramid fibers as part of the linear bodies constituting the mesh body, and linear bodies made of PVA fibers as the other part of the linear bodies.

Example 8
A concrete structure according to Example 8 was produced in the same manner as in Example 1, except that in one of the three directions of linear members constituting the network, linear members having a total fineness of 6680 dtex made of para-type wholly aromatic polyamide fiber (TN, "Technora (registered trademark)" manufactured by Teijin Limited) were used instead of linear members made of PVA fiber, and a push-out test was carried out. The results are shown in Table 2 below.

Example 9
A concrete structure according to Example 9 was produced in the same manner as in Example 1, except that in two of the three directions of linear members constituting the network, linear members with a total fineness of 6680 dtex made of para-type wholly aromatic polyamide fiber (TN, "Technora (registered trademark)" manufactured by Teijin Limited) were used instead of linear members made of PVA fiber, and a push-out test was carried out. The results are shown in Table 2 below.

As can be seen from Table 2, the concrete structures according to Examples 8 and 9, which have concrete reinforcement in which a portion of the linear bodies contains PVA fibers and another portion of the linear bodies contains TN fibers, have relatively high resistance when the degree of displacement is relatively large (when the displacement is 40 mm or 50 mm), compared to the concrete structures according to Comparative Examples 1 and 2, which have concrete reinforcement containing only TN fiber-containing linear bodies.

It can be seen that the concrete structures according to Examples 8 and 9 (see Table 2), which have a concrete reinforcement material in which a part of the linear body contains PVA fiber and another part of the linear body contains TN fiber, have a relatively large resistance when the degree of displacement is relatively small (when the displacement is 20 mm or 30 mm), compared to the concrete structure according to Example 1 (Table 1), which has a concrete reinforcement material containing PVA fiber. Therefore, it can be seen that according to the concrete reinforcement material according to the present disclosure, by setting the type and/or the ratio of the fibers contained in the concrete reinforcement material, a concrete reinforcement material that exhibits an optimal resistance depending on the degree of displacement can be obtained.

10, 30, 40, 50, 60, 70 Concrete reinforcement 11 Concrete structure 12, 32, 42, 52, 62, 52a, 52b, 52c, 62a, 62b, 62c, 62d, 72 Linear body 14, 34, 44, 54, 64, 74 Convex body 15 Cover portion 16, 76 Reinforcement bar 17 Concrete 20 Prestressed concrete box girder 21 Lower deck 22 Web 23 Overhanging portion of upper deck 79 Mortar spacer 78 Formwork 78a Bottom of formwork D1, D2, D3, D4, D5, D6, D7 Direction

Claims (16)

A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh-like body composed of linear bodies, and protruding bodies distributed on a surface of the mesh-like body,
the protruding body protrudes at least in a direction perpendicular to a surface direction of the mesh body,
The net-like body includes linear bodies containing aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and linear bodies containing one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers and not containing the aliphatic resin fibers , and the linear bodies constituting the net-like body have a total fineness of 3,500 decitex to 50,000 decitex,
the linear bodies constituting the mesh body extend along a first direction, a second direction, and a third direction, and the first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°;
The linear body extending along the first direction contains the aliphatic resin fiber, and
The linear body extending along the second direction is the linear body containing the additional fiber.
Concrete reinforcement. A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh body made up of linear bodies and protruding bodies distributed on a surface of the mesh body,
the protruding body protrudes in at least a direction perpendicular to a surface direction of the mesh body,
The net-like body includes linear bodies containing aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and linear bodies containing one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers and not containing the aliphatic resin fibers , and the linear bodies constituting the net-like body have a total fineness of 3,500 decitex to 50,000 decitex,
the linear bodies constituting the reticulate body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction, the fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°, the sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and also intersect with the fourth direction and the fifth direction at an angle of 40° to 50°,
The linear body extending along the fourth direction contains the aliphatic resin fiber, and
A concrete reinforcement material, wherein the linear body extending along the fifth direction is a linear body containing the additional fibers. A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh-like body composed of linear bodies, and protruding bodies distributed on a surface of the mesh-like body,
the protruding body protrudes at least in a direction perpendicular to a surface direction of the mesh body,
The net-like body includes linear bodies containing aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and linear bodies containing one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers and not containing the aliphatic resin fibers , and the linear bodies constituting the net-like body have a total fineness of 3,500 decitex to 50,000 decitex,
And the following conditions 1 and 2:
Condition 1: The linear bodies constituting the mesh body extend along a first direction, a second direction, and a third direction, and the first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°.
Condition 2: the linear bodies constituting the reticulate body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction, the fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°, the sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and also intersect with the fourth direction and the fifth direction at an angle of 40° to 50°,
The convex body separates the mesh body from the surface of a concrete molding form by a predetermined length when the concrete reinforcement is brought into contact with the formwork, and
The predetermined length is set to a degree that mortar in the concrete or cement paste in the concrete penetrates between the formwork and the reticulate body when concrete is poured into the formwork.
Concrete reinforcement. A concrete reinforcement material to be embedded in concrete,
The present invention has a mesh body made up of linear bodies and protruding bodies distributed on a surface of the mesh body,
the protruding body protrudes in at least a direction perpendicular to a surface direction of the mesh body,
The net-like body includes linear bodies containing aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and linear bodies containing one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers and not containing the aliphatic resin fibers , and the linear bodies constituting the net-like body have a total fineness of 3,500 decitex to 50,000 decitex,
And the following conditions 1 and 2:
Condition 1: The linear bodies constituting the mesh body extend along a first direction, a second direction, and a third direction, and the first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°.
Condition 2: the linear bodies constituting the reticulate body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction, the fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°, the sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and also intersect with the fourth direction and the fifth direction at an angle of 40° to 50°,
The convex body is a mineral granule adhered to the mesh body via an adhesive.
Concrete reinforcement. The concrete reinforcing material according to any one of claims 1 to 4, wherein the linear body containing the aliphatic resin fibers is a thread made by twisting the aliphatic resin fibers together, or a string-like body made by bundling the aliphatic resin fibers. The concrete reinforcing material according to any one of claims 1 to 5, wherein the linear body containing aliphatic resin fibers contains aliphatic resin fibers formed from polyvinyl alcohol (PVA). The concrete reinforcing material according to any one of claims 1 to 5, wherein the linear body containing the aliphatic resin fiber contains aliphatic resin fibers formed from a polyolefin, and the polyolefin is polypropylene, polymethylpentene, or polyethylene. The concrete reinforcing material according to any one of claims 1 to 5, wherein the linear body containing the aliphatic resin fiber contains aliphatic resin fibers formed from a polyolefin, and the polyolefin is polypropylene. The concrete reinforcing material according to any one of claims 1 to 5, wherein the linear body containing the aliphatic resin fiber contains aliphatic resin fibers formed from a polyolefin, and the polyolefin is polymethylpentene. The concrete reinforcing material according to any one of claims 1 to 5, wherein the linear body containing the aliphatic resin fiber contains aliphatic resin fibers formed from a polyolefin, and the polyolefin is polyethylene. The concrete reinforcing material according to any one of claims 1 to 5, wherein the linear body containing aliphatic resin fibers contains aliphatic resin fibers formed from aliphatic polyamide. The linear body containing the aliphatic resin fibers is a thread made by twisting the aliphatic resin fibers together, or a string-like body made by bundling the aliphatic resin fibers, and
The linear body containing the additional fibers is a thread made by twisting the additional fibers together, or a string-like body made by bundling the additional fibers together.
The concrete reinforcement material according to any one of claims 1 to 11. The concrete reinforcement material according to any one of claims 1 to 12, wherein the additional fibers are aromatic resin fibers, and the aromatic resin fibers are aramid fibers. The concrete reinforcement material according to any one of claims 1 to 13, wherein the mesh body is formed by weaving together the linear bodies. A concrete structure having the concrete reinforcement according to any one of claims 1 to 14, wherein the concrete reinforcement is embedded near a surface of the concrete structure along a surface direction of the surface.
Concrete structure. A method for manufacturing a concrete structure, comprising the steps of:
To provide a formwork for concrete casting;
A concrete reinforcing material is provided, the concrete reinforcing material being embedded in concrete, the concrete reinforcing material having a mesh body composed of linear bodies and protruding bodies distributed on a surface of the mesh body;
placing the concrete reinforcement along the inner surface of the formwork such that the convex portion of the concrete reinforcement contacts the bottom of the formwork, thereby forming a gap between the mesh of the concrete reinforcement and the bottom of the formwork; and pouring concrete into the formwork such that the concrete, the mortar in the concrete, and/or the cement paste in the concrete flows into the gap, thereby embedding the mesh in the concrete.
With respect to the concrete reinforcement,
the protruding body protrudes in at least a direction perpendicular to a surface direction of the mesh body,
The net-like body includes linear bodies containing aliphatic resin fibers formed from one or more synthetic resins selected from polyvinyl alcohol (PVA), polyolefin, and aliphatic polyamide, and linear bodies containing one or more additional fibers selected from metal fibers, aromatic resin fibers, carbon fibers, glass fibers, and basalt fibers and not containing the aliphatic resin fibers , the linear bodies constituting the net-like body having a total fineness of 3,500 decitex to 50,000 decitex, and satisfying the following conditions 1 and 2:
Condition 1: The linear bodies constituting the mesh body extend along a first direction, a second direction, and a third direction, and the first direction, the second direction, and the third direction intersect with each other at an angle of 55° to 65°.
Condition 2: the linear bodies constituting the reticulate body extend along a fourth direction, a fifth direction, a sixth direction, and a seventh direction, the fourth direction and the fifth direction intersect with each other at an angle of 85° to 95°, the sixth direction and the seventh direction intersect with each other at an angle of 85° to 95°, and also intersect with the fourth direction and the fifth direction at an angle of 40° to 50°, respectively.
Either of the following is satisfied:
A method for manufacturing a concrete structure.

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