JPH06264560A - Concrete structure body and manufacture thereof - Google Patents

Abstract

PURPOSE:To reinforce a concrete structure body by the reinforcing members having a high utilization efficiency of the reinforcing fibers and the large pull- out resistance. CONSTITUTION:The warp 11 and weft 12 made of reinforced fibers cross each other in a cross angle theta of 90 deg.<theta<=170 deg., at different positions, and the obliquely crossing mesh shaped reinforcing members which are joined by resin are arranged in a mold frame, and the mortar containing the short fibers for reinforcement in 0.1-5 volume% is laid in a mold frame, and a concrete structure body is obtained. The obliquely crossing mesh shaped reinforcing member may be a sheet or three-dimensional shape. The obliquely crossing mesh shaped reinforcing members are arranged in the mold frame, directing the acute angle part in the crossing part, with respaect to the direction of the stress acting on the structure body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete structure in which a reinforcing material is embedded in various types of concrete and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a concrete structure, a structure in which short fibers of reinforcing fibers are mixed in concrete is known. However, when the short fibers are mixed, the short fibers are randomly oriented, so that the reinforcing effect of the fibers cannot be effectively utilized in the direction in which stress mainly acts, and shrinkage or cracking easily occurs. Moreover, the reinforcing properties are small with only short fibers. Therefore, it is necessary to mix a large amount of short fibers.

Therefore, in Japanese Patent Laid-Open No. 178644/1987, long fibers which are continuous in one direction are embedded along the direction in which the tensile force of the concrete structure acts, and the short length of the reinforcing fiber is embedded in the concrete. A fiber reinforced concrete structure containing fibers is disclosed.

Since this structure embeds continuous long fibers in a specific direction, it has a high reinforcing property in the direction in which the tensile force acts, but in the direction orthogonal to the orientation direction (tensile direction) of the long fibers. It is difficult to enhance the reinforcing property. Moreover, since the long fibers are arranged in one direction, the long fibers as a reinforcing material are easily pulled out from the concrete.

Further, Japanese Patent Application Laid-Open No. 63-2867 discloses that
Inside the concrete structure, the short fibers 1 to 1 of the reinforcing fibers
Disclosed is a fiber-reinforced concrete structure in which 0.2% by volume is mixed and 0.1 to 0.2% by volume of mesh fibers are embedded in a direction in which a tensile force of the concrete structure acts.

Since this structure uses the lattice-shaped orthogonal mesh fibers, it has higher reinforcement than the structure in which the long fibers are embedded in one direction. However, in a concrete structure, a load generally acts in a specific direction. Therefore, although the strength of the mesh fibers can be effectively used in the direction of the main muscle to which the tensile force acts, the reinforcement becomes excessive in the direction of the force distribution muscle that is orthogonal to the main muscle direction, and the effective utilization efficiency of the fibers is small. Further, since the warp yarns or the weft yarns of the lattice-shaped orthogonal mesh fiber are embedded in the main bar direction, the fiber is easily pulled out.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a concrete structure which has a high utilization efficiency of reinforcing fibers and a large pull-out resistance, and is excellent in reinforcing properties.

Another object of the present invention is to provide a method capable of efficiently producing a highly reinforced concrete structure having high workability.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present inventors have generally paid attention to the fact that a stress in a specific direction acts on a concrete structure, and as a result of earnest studies to achieve the above-mentioned object, concrete containing a short fiber of a reinforcing fiber. In, by embedding a diagonal mesh-shaped reinforcing material in which the reinforcing fibers intersect each other in an oblique direction, not only the pull-out resistance of the fiber is large, but also the utilization efficiency of the fiber is high, and it is possible to impart high reinforcing property even in a small amount. Found and completed the present invention.

That is, in the concrete structure of the present invention, in the concrete, the warp yarns and the weft yarns made of reinforcing fibers intersect at different positions at an intersecting angle θ of 90 ° <θ ≦ 170 °, and The diagonal mesh-shaped reinforcing material that is joined is embedded, and the short fibers of the reinforcing fibers are mixed.

Further, in the method of the present invention, the above-mentioned diagonal mesh reinforcing material is arranged in a mold, and mortar containing short fibers of reinforcing fibers is cast in the mold to form a concrete structure. To manufacture.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings as needed.

In the diagonal mesh reinforcing material, it is sufficient that the warp yarns and the weft yarns made of the reinforcing fibers intersect each other at different positions at the intersecting angle θ and are joined together. The reinforcing material is usually composed of a warp yarn and a weft yarn of a resin-impregnated fiber bundle, a plurality of warp yarns forming a warp yarn group extending at intervals in one direction, and in a direction intersecting the direction. A plurality of weft yarns forming a weft yarn group extending at intervals are sequentially laminated and crossed at different positions and joined by an impregnating resin.

Such a diagonal mesh reinforcing material can be obtained by various methods, for example, by crossing and joining resin-impregnated fiber bundles in a mesh shape at the above-mentioned angle or by intersecting them in a mesh shape to form a fiber bundle. Resin may be impregnated and joined. Moreover, the warp yarn and the weft yarn may be intertwined with each other at the intersection. The diagonal mesh reinforcing material is obtained by the pin winding method in which the fiber bundle is sequentially hooked on the pins arranged in the surroundings in a one-stroke manner so that the crossing angle θ is oblique within the range of 45 ° <θ ≦ 85 °. You can also

The diagonal mesh reinforcing member has a winding angle θ of 45 ° <θ with respect to the rotating body while reciprocally moving the resin-impregnated fiber bundle along the rotating shaft direction of the rotating body.
It can be efficiently obtained by winding it in a mesh shape around the rotating body within a range of ≦ 85 ° and processing the wound fiber bundle into a sheet shape or a three-dimensional shape.

FIG. 1 is a schematic perspective view for explaining a method for manufacturing a cross mesh reinforcing material used in the present invention. In this method, the fiber bundle 1 is fed to the guide rollers 4a, 4b, 4c.
The resin-impregnated fiber bundle 5 is wound around the rotary drum 7 while being reciprocated by the traverse roller 6 while being immersed in the resin solution 3 in the impregnation tank 2 while being guided and impregnated with the resin. In such a method, the traverse roller 6 can be wound around the rotary drum 7 while reciprocating along the axial direction of the rotary drum 7.

The winding angle θ1 of the resin-impregnated fiber bundle 5 around the rotary drum 7 is in a range in which the warp yarns and the weft yarns are not orthogonal to each other, for example, 45 ° <θ1 depending on the desired reinforcing fiber structure.
≤85 °, preferably about 50 ° ≤θ1 ≤70 °.

The reinforcing fibers constituting the fiber bundle 1 are, for example, polymer fibers such as polyacrylonitrile, phenol resin and rayon, carbon fibers made of petroleum or coal pitch; polypropylene fibers; alkali glass fibers; Aromatic polyamide fibers (such as aramid fibers);
Examples thereof include polyvinyl alcohol-based synthetic fibers (high-strength vinylon fibers); polyether sulfone fibers and the like. At least one of these fibers can be used.

Among these fibers, in order to enhance the reinforcing effect on concrete, the tensile elastic modulus is 5 × 10 ³ kgf.
/ Mm ² or more fibers such as carbon fibers and aramid fibers are preferable.

The carbon fiber means a carbonized or graphitized fiber, and a fiber fired at a high temperature of about 1500 ° C. or higher is included in the concept of graphitization even when the crystal structure is not graphitized. When carbon fiber is used as the reinforcing fiber, the concrete member can be provided with a shielding property against electromagnetic waves.

The filament diameter of the fiber is, for example, about 5 to 30 μm. A fiber bundle is made up of a suitable number of strands, for example 500
It can be composed of about 480000 strands.

The fiber bundle may be wound around a rotary drum without twisting. However, twisting can prevent the fiber bundle from being flat when wound around the drum, and can be adhered to concrete. Can be increased. Moreover, since the cross section is circular, the bending rigidity of the reinforcing material itself is increased, and the workability during transportation and construction is improved. The number of twists of the fiber bundle can be appropriately selected, but 5 to 3 per 1 m
It is 0 times, preferably about 10 to 15 times. The twisting of the fiber bundle may be performed before the resin is impregnated, or may be performed during or after the resin impregnation.

As the resin with which the fiber bundle is impregnated, thermosetting resins such as epoxy resin, phenol resin, vinyl ester resin, diallyl phthalate resin, unsaturated polyester resin, thermosetting acrylic resin, polyurethane resin and polyimide; polyacetal Examples thereof include thermoplastic resins such as polysulfone, polyether sulfone, polyphenylene sulfide, polyphenylene oxide, polyarylate, and aromatic polyamide. The above resins are used alone or in combination of two or more. Of these resins, thermosetting resins, particularly epoxy resins, vinyl ester resins, and phenol resins, whose characteristics are less likely to be deteriorated by the alkali component of cement, are preferable. When a thermosetting resin is used, a curing agent depending on the type of resin can be used.

The resin need only have a viscosity capable of impregnating the fiber bundle, and may be dissolved in an organic solvent such as hydrocarbons, alcohols, esters, ketones and ethers as necessary. It can be used as a concentrated solution or a dispersed dispersion.

The amount of resin impregnated can be selected within a range that does not impair the integrity of the fiber bundle. For example, the volume content is 10 to 80.
%, Preferably about 20 to 60%. If necessary, the resin excessively attached to the fiber bundle in the resin impregnation step may be removed by a squeezing means, or the organic solvent may be removed by a drying means after the resin impregnation.

By reciprocating the resin-impregnated fiber bundle 5, it can be wound around the rotary drum 7 in a mesh shape. Fiber bundle 5
The reciprocating movement is not limited to the traverse roller 6, and, for example, a locking piece that locks with the resin-impregnated fiber bundle 5 and a reciprocating movement that causes the locking piece to reciprocate along the axial direction of the rotary drum 7. It may be controlled by adjusting the reciprocating speed of the reciprocating means constituted by the moving mechanism.

In such a method, the mesh interval in the reinforcing fibers and the angle of the fiber bundle 5 can be arbitrarily controlled by adjusting the reciprocating speed of the reciprocating means and the rotating speed of the rotary drum 7 relatively. . Further, the reinforcing materials having different mesh intervals and different fiber bundle angles can be efficiently manufactured by a simple operation of reciprocating the resin-impregnated fiber bundle 5 and winding it around the rotary drum 7.

Further, by reciprocating one resin-impregnated fiber bundle 5 at least once, a warp yarn group composed of a plurality of warp yarns extending at intervals in one direction and a warp yarn group in a direction intersecting the direction. It is also possible to intersect a weft thread group composed of a plurality of weft threads extending at intervals, and by reciprocating a plurality of times at different winding positions with respect to the rotating drum 7, the positions of the warp thread and the weft thread are displaced. You can also cross. In the latter case, the plurality of warp yarn groups and the plurality of weft yarn groups can be sequentially crossed at different positions from each other in a laminated state.

In a preferred method, one resin-impregnated fiber bundle 5 is wound in one direction at a predetermined pitch to form warp yarns, and is wound at a predetermined pitch in a direction intersecting the formed warp yarns. After forming the weft yarn, a method of displacing the position at least once or more in the one direction and the intersecting direction, preferably by displacing the position at substantially regular intervals and reciprocating, is included.

Further, since the resin-impregnated fiber bundle is wound around the rotating body, adjusting the tension of the resin-impregnated fiber bundle increases the adhesion between the fiber bundles as in the case of pressing the resin-impregnated fiber bundle. be able to. Further, since all the resin-impregnated fiber bundles can be crossed, the material can be effectively used.

The mesh spacing of the reinforcing fibers wound around the rotary drum 7 can be appropriately set according to the reinforcing performance, and is, for example, 2 mm or more, preferably 5 to 300 mm, more preferably 10 to 200 mm. If the mesh spacing is less than 2 mm, the amount of cement mortar filled between the meshes is small and the reinforcing property is insufficient.

A sheet-like or three-dimensional oblique mesh reinforcing material can be obtained from the fiber bundle thus wound in a mesh shape.

When the resin is a thermoplastic resin, the sheet-shaped reinforcing material can be used as it is as a mesh-shaped reinforcing material by cutting the wound reinforcing fiber and removing it from the rotary drum. Further, when the resin is a thermosetting resin, by cutting the wound reinforcing fiber into a sheet by removing from the rotating drum, by curing,
A mesh-shaped reinforcing material can be obtained. The fiber bundle can be removed from the rotary drum by cutting the wound fiber bundle with a cutter or the like and peeling it off. The cutting direction of the wound fiber bundle is not particularly limited as long as it can be removed from the rotating body, but it is preferable to cut in the axial direction of the rotating body. When a thermosetting resin is used, it is often peeled to form a sheet and then subjected to a curing step.
The thermosetting resin can be usually cured at a temperature of room temperature to about 200 ° C.

In order to facilitate the peeling of the wound fiber bundle, the rotary drum may be pre-coated with a fluorine-based coating agent or the like, or may be pre-coated with a peelable film.

The three-dimensional reinforcing material may be obtained by removing the mesh-shaped prepreg from the rotary drum, but if a sheet-shaped prepreg is used, various three-dimensional reinforcing materials can be obtained by molding. There is an advantage that it can be obtained.

The solid shape of the reinforcing material is not particularly limited, and may be a polygonal cross section such as a cylinder, an elliptic cylinder, a triangular cross section, a quadrangular cross section, a hexagonal cross section, or an irregular cross section such as an H cross section. Good.

A method of forming a mesh body, which is a sheet-like prepreg, into a three-dimensional reinforcing material is a conventional method, for example, in the case of a cylindrical or polygonal cross section, a circular or polygonal cross section is used. It can be performed by winding a sheet-like prepreg around the mold or using a predetermined mold in accordance with a molding method such as pressure molding or autoclave molding. Also,
When the cross-section has a different shape, it can be performed in the same manner as described above by using a predetermined mold and according to a molding method such as pressure molding or autoclave molding.

By adopting a pressure molding method or an autoclave molding method in the molding step, it is possible to suppress the formation of a step at the intersection of the three-dimensional reinforcing material, and to obtain a reinforcing material having a high joint strength and high integrity. be able to. The reinforcing material having a rectangular cross section or an H shape may be a reinforcing material such as a beam or a board. At the time of molding, a plurality of sheet-shaped prepregs may be laminated and molded.

When a thermosetting resin is used, the three-dimensional reinforcing material can be obtained by subjecting the molded prepreg to the curing step.

As is clear from the above, the main feature of the present invention resides in the use of the diagonal mesh reinforcing material in which the warp threads and the weft threads are not orthogonal to each other. In this reinforcing material, the crossing angle θ2 between the warp yarn and the weft yarn can be appropriately selected within the above range depending on the shape of the concrete structure, the main load direction acting on the concrete structure, etc., but preferably 1
It is about 00 ° ≤θ2≤140 °.

FIG. 2 is a schematic sectional view showing an example of the concrete structure of the present invention. In this example, the oblique mesh reinforcing material embedded in concrete is one warp group consisting of warp yarns 11 extending at a predetermined interval in one direction,
A weft thread 1 extending at a predetermined interval in a direction intersecting with the warp thread 11.
The warp yarn 11 and the weft yarn 12 intersect each other and are joined in a laminated state at the intersection. In addition, in the concrete between the warp yarn 11 and the weft yarn 12 of the diagonal mesh reinforcing material, short fibers 13 of reinforcing fibers are included.
Are dispersed and mixed.

In a concrete structure in which such a diagonal mesh reinforcing material is embedded, when the stress F in the main load direction acts, the warp 1 in which the stress F diagonally intersects
The force is divided by 1 and the weft thread 12. Therefore, the reinforcing property can be enhanced by embedding the oblique mesh reinforcing material in the direction in which the stress F acts on the structure with the acute angle portion of the intersection facing. In addition, warp 1
Since 1 and the weft 12 are arranged in an oblique direction, the pullout resistance from the concrete is large. Therefore, the reinforcing efficiency of the mesh-shaped reinforcing material against stress such as bending load is high, and the effective rate of the fiber can be improved. Furthermore, the short fibers 13 can disperse cracks in the concrete structure, and improve shear reinforcement and toughness. Therefore, the oblique mesh reinforcing material and the short fibers 13 can ensure a high reinforcing property of the concrete structure.

The short fibers can be appropriately selected from the exemplified reinforcing fibers, and the kind thereof may be different from that of the reinforcing mesh-like reinforcing material.

The length of the short fibers is, for example, 0.1 to 10 m.
m, and short fibers of about 0.5 to 7.5 mm are often used. The aspect ratio of the short fibers is preferably about 50 to 5000 in order to enhance the reinforcing property.

The mixing ratio of the short fibers can be selected according to the desired strength of the concrete structure, and is, for example, 0.1 to 0.1.
It is about 5% by volume, preferably about 0.5 to 5% by volume.

In the reinforcing member shown in FIG. 2, the resin-impregnated fiber bundle is wound around a rotating body at a predetermined pitch in one direction to form warp yarns 11, and the warp yarns 11 are crossed with each other. However, the weft yarn 12 can be manufactured by winding the warp yarn 11 around the warp yarn 11 at a predetermined pitch.

FIG. 3 is a schematic sectional view showing another example of the concrete structure of the present invention. In the oblique mesh reinforcing material of this example, the warp yarns 2 extending at a predetermined interval in one direction
1a, a first weft yarn group consisting of weft yarns 22a extending at a predetermined interval in a direction intersecting the warp yarn 21a, and a warp yarn 21b extending at a predetermined interval in the one direction.
A second warp yarn group consisting of and a warp yarn 21 of the second warp yarn group.
A second weft yarn group consisting of weft yarns 22b extending at a predetermined interval in a direction intersecting b is sequentially intersected at different positions, and is joined in a laminated state at the intersection. Further, the warp yarns 21a and 21b and the weft yarn 2 of the diagonal mesh reinforcing material are
Short fibers 23, which are reinforcing fibers, are mixed in the concrete between 2a and 22b.

In the reinforcing material having the structure shown in FIG. 3, the resin-impregnated fiber bundle is wound in one direction at a predetermined pitch to form the first warp yarn 21a, and the first warp yarn 21a is crossed with the wound warp yarn 21a. The first weft yarn 22a is wound around the warp yarn 21a at a predetermined pitch. Next, the resin-impregnated fiber bundle is wound in the one direction at a pitch positioned between the first warp yarns 21a and while intersecting the first weft yarns 22a to form the second warp yarns 21b. , At a pitch located between the first weft threads 22a, and
The second weft yarn 22b can be manufactured by winding the first weft yarn 21a and the second warp yarn 21b on the first and second warp yarns 21a and 21b while intersecting the warp yarn 21a.

FIG. 4 is a schematic sectional view showing still another example of the concrete structure of the present invention. In this example, the oblique mesh reinforcing material embedded in the concrete includes a first warp group consisting of warp threads 31a extending in one direction at a predetermined interval, and a weft thread extending in a direction intersecting with the warp thread 31a. A first weft thread group consisting of 32a, a second warp thread group consisting of a warp thread 31b similar to the above, a second weft thread group consisting of a weft thread 32b similar to the above, and a third warp thread group consisting of a warp thread 31c. , And a third weft yarn group consisting of weft yarns 32c sequentially intersect at different positions and are joined in a laminated state at the intersecting portion. In addition, the warp yarns 31a,
Short fibers 33 of reinforcing fibers are mixed between 31b and 31c and the weft threads 32a, 32b and 32c.

In the reinforcing material shown in FIG. 4, the second and third warp yarns 31b and 31c are positioned at substantially equal intervals between the first warp yarns 31a, and the second and third warp yarns 32a are arranged between the first warp yarns 32a. Weft 32
b and 32c are arranged at substantially equal intervals, and the plurality of warp yarns 31 between the first warp yarn 31a and the third weft yarn 32c are arranged.
It can be manufactured by alternately intersecting b, 31c and weft threads 32a, 32b.

The warp and weft pitches may be the same or different. Further, the numbers of filaments and the diameters of the warp yarns and the weft yarns may be the same or different. The number of warp yarn groups that form the warp yarns of the reinforcing material and the number of weft yarn groups that form the weft yarns may be the same or different as long as the weft yarns or the warp yarns intersect with each other.

The embedding position (fogging) of the oblique mesh reinforcing material can be appropriately selected according to the shape, thickness and size of the concrete structure. Further, the number of plies of the diagonal mesh reinforcing material may be plural. Furthermore, the proportion of the diagonal mesh reinforcement in the concrete structure is also
It can be selected according to the size of the concrete structure, etc., and is usually 0.05 to 5% by volume, preferably 0.1 to 3% by volume.
It is a degree.

The reinforcing material may be surface-treated with a silane coupling agent, a titanium coupling agent or the like in order to enhance the affinity with concrete, and further, the surface may be sanded or sanded. By doing so, the uneven portion may be formed. The fiber bundle may be impregnated with a silane coupling agent, sand or the like together with the resin.

The concrete structure of the present invention can be manufactured by arranging the above-mentioned oblique mesh reinforcing material in a mold and placing mortar containing short fibers of reinforcing fibers in the mold. The disposing direction of the oblique mesh reinforcing material is not particularly limited, but the reinforcing property in the direction in which the acute angle portion faces can be enhanced rather than the reinforcing property in the direction in which the obtuse angle portion faces at the intersecting portion of the reinforcing material. Therefore, as shown in FIG. 2, the oblique mesh reinforcing material is arranged in the form with the acute angle portion of the intersection facing in the direction of the stress F acting on the concrete structure, and embedded in the concrete. Preferably.

When the sheet-shaped reinforcing material is arranged in the above-mentioned direction, in the rectangular concrete structure such as the panel, the curtain wall, the floorboard, the wallboard, and the formwork, as described above, the oblique mesh shape is formed. Since the stress in the main load direction is divided by the reinforcing material, the reinforcing property in the longitudinal direction can be enhanced. Further, as described above, since the pullout resistance from the concrete is large, the reinforcing effect can be further enhanced. In the rectangular concrete structure as described above, a load is often applied in the longitudinal direction rather than in the short side direction, so that sufficient strength can be secured also in the short side direction.

Further, since the warp yarns and the weft yarns cross each other obliquely in the reinforcing material, the reinforcing material has anisotropy in that the rigidity becomes high in the longitudinal direction of the mesh muscle itself, that is, in the direction in which the acute angle portion is oriented at the intersection. Therefore, unlike the orthogonal mesh that exhibits isotropic properties, it is possible to improve the workability when arranging in the mold.

When a three-dimensional reinforcing material, for example, a cylindrical or rectangular reinforcing material is used as a reinforcing material for a columnar or prismatic concrete structure such as a beam member,
Bending reinforcement in the longitudinal direction and shear reinforcement in the thickness direction can be performed simultaneously. In addition, the ratio between the bending strength and the shear strength can be adjusted by adjusting the intersecting angle of the warp yarn and the weft yarn according to the shape of the concrete structure.

In particular, the warp yarns of a plurality of warp yarn groups and the weft yarns of a plurality of weft yarn groups have different positions as compared with the reinforcing member as shown in FIG. 2 which is composed of one warp yarn group and one weft yarn group. With the diagonal mesh reinforcing material that intersects with each other, when a panel having a large area or a three-dimensional concrete structure is produced, bending bending is small, workability is improved, and a reinforcing effect is large.

The mortar to be placed in the mold can be prepared by a conventional method of mixing cement, water and short fibers of reinforcing fibers. The type of cement is not particularly limited, for example,
Self-hardening cements such as Portland cement, early-strength Portland cement, alumina cement, rapid-hardening high-strength cement, and burnt gypsum; hydraulic cements such as lime slag cement and blast-furnace cement; mixed cements.

The mortar may contain an aggregate, a set retarder, an effect accelerator, a water reducing agent, a coagulant, a thickener, a foaming agent, a waterproofing agent and the like.

The cement placed in a predetermined mold may be cured by a conventional method such as steam curing or autoclave curing.

[0062]

EFFECTS OF THE INVENTION Since the concrete structure of the present invention contains the oblique mesh reinforcing material and the short fibers of the reinforcing fibers, the utilization efficiency of the reinforcing fibers and the pull-out resistance are large and a high reinforcing property is obtained even in a small amount. Show.

The method of the present invention has anisotropy,
A mortar containing short fibers of reinforcing fibers is placed using a light mesh, diagonal mesh reinforcing material that is highly transportable and easy to construct. Therefore, it is possible to efficiently manufacture a highly reinforced concrete structure having high workability.

[0064]

EXAMPLES The present invention will be described in more detail based on the following examples.

Example 1 Three polyacrylonitrile-based carbon fibers (tensile strength 300 kgf / mm ² , tensile elastic modulus 24 × 10 ³ kgf / mm ² ) having a wire number of 12,000 (12K) were collected to make 36K, and 12 per 1 m. Twisted twice.

10 bisphenol A type epoxy resin (trade name Epicoat 827, manufactured by Yuka Shell Co., Ltd.) was added to this fiber bundle.
0 parts by weight, acid anhydride type curing agent (Made by Petrochemical Co., M
NA) 90 parts by weight and curing accelerator (produced by Yuka Shell Co.,
EMI-24) While impregnating with 1 part by weight of the solution, 20
At a yarn speed of m / min, a crossing angle of 130 ° on the rotating drum,
It was wound so that the fiber interval (mesh interval) was 5 cm.

After the completion of winding, the operation of the apparatus was stopped, one side of the wound resin-impregnated fiber bundle was cut open to form a sheet, and the resin was cured at 150 ° C. for 4 hours to give a resin content of 50. A weight percent reinforcement was obtained. The obtained reinforcing material was cut into a piece having a width of 500 mm and a length of 1000 mm.

Pitch-based carbon fibers (tensile strength 60 kgf / mm ² , tensile modulus 4
× 10 ³ kgf / mm ² , fiber diameter = 18 μm, fiber length =
3 mm) and cement mortar containing 2.0% by volume of the above short fibers [water / early strength Portland cement = 50
%, Silica sand / early strength Portland cement = 0.25].

Then, a mesh-like reinforcing material (0.
(3% by volume) One piece is placed at a position of covering 5 mm, cement mortar containing the short fibers is placed, and after curing, the material is cooled for 7 days, and a panel-shaped concrete structure (thickness 30 mm, width 500 mm, length) 1000 mm) was prepared and a 3-point bending test was performed.

In the mesh-like reinforcing material, the acute angle portion of the intersecting portion was arranged in the form with the panel-like concrete structure oriented in the longitudinal direction.

Example 2 Vinylon fibers (tensile strength 150 kgf / mm ² , tensile elastic modulus 3.7 × 10 ³ kgf / mm ² , fiber diameter = 20 μm) were used as short fibers instead of the short carbon fibers of Example 1. ,
A concrete structure was prepared in the same manner as in Example 1 except that the fiber length = 3 mm) was used, and a three-point bending test was performed.

Example 3 Instead of polyacrylonitrile-based carbon fiber, aramid fiber (tensile strength 280 kgf / mm ² , tensile elastic modulus 14 ×)
10 ³ kgf / mm ² ) is used in the same manner as in Example 1 to produce an oblique mesh reinforcing material, and the vinylon short fibers used in Example 2 are used in place of carbon fibers as short fibers. In the same manner as in Example 1, a concrete structure (oblique mesh mesh reinforcing material 0.3% by volume, short fiber mixing ratio 2.0% by volume) was prepared and a three-point bending test was performed.

COMPARATIVE EXAMPLE 1 The epoxy resin composition used in Example 1 was impregnated into the 36K polyacrylonitrile-based carbon fiber bundle of Example 1 which was twisted 12 times per meter, and the pin was struck around the plate. An orthogonal mesh reinforcing material having a crossing angle of 90 ° and a fiber interval (mesh interval) of 5 cm was produced by the pin winding method of sequentially applying in the vertical direction and the horizontal direction in a single-stroke manner.

A panel-shaped concrete structure (orthogonal mesh reinforcing material 0.3% was used) in the same manner as in Example 1 except that the obtained orthogonal mesh reinforcing material was used in place of the oblique mesh reinforcing material of Example 1. Volume%, fog 5 mm, mixing ratio of short fibers of carbon fibers 2.0% by volume) was prepared and a three-point bending test was performed.

Comparative Example 2 In the same manner as in Example 1 without mixing short fibers of carbon fibers into cement mortar, a panel-like concrete structure in which one cross mesh reinforcing material of Example 1 was embedded with a cover of 5 mm A body (oblique mesh mesh reinforcing material 0.3% by volume) was prepared and a 3-point bending test was conducted.

Comparative Example 3 A panel-shaped concrete structure (mixing ratio of short carbon fibers of 2.0% by volume) was prepared in the same manner as in Example 1 without using the oblique mesh reinforcing material, and 3 points were prepared. A bending test was performed.

The measurement results of bending strength are shown in the table. 3
In the point bending test, the occurrence of cracks, which is a measure of toughness and shear reinforcement, was evaluated based on the result (medium) of the structure of Comparative Example 1 according to the following criteria. Shown in.

Excellent: Large number of cracks and high toughness Good: Medium number of cracks Fair: Medium number of cracks (Comparative Example 1) Poor: Small number of cracks and small toughness

[0079]

[Table 1] As is clear from the table, the concrete structures of Examples 1 to 3 using the oblique mesh reinforcing material and the short fibers of the reinforcing fibers have a greater strength than the concrete structures of Comparative Examples 1 to 3. In addition, it has high toughness and shear reinforcement.

[Brief description of drawings]

FIG. 1 is a schematic perspective view for explaining a method for manufacturing a cross mesh reinforcing material used in the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of the concrete structure of the present invention.

FIG. 3 is a schematic cross-sectional view showing another example of the concrete structure of the present invention.

FIG. 4 is a schematic sectional view showing still another example of the concrete structure of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fiber bundle 5 ... Resin impregnated fiber bundle 11,21a, 21b, 31a, 31b, 31c ... Warp yarn 12,22a, 22b, 32a, 32b, 32c ... Weft yarn 13,23,33 ... Short fiber

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoji Dohi, 4-1-2, Hirano-cho, Chuo-ku, Osaka, Osaka Gas Co., Ltd. (72) Atsushi Nakane 4-640, Shimourado, Kiyose-shi, Tokyo Stock company Obayashi Technical Research Institute (72) Inventor Kenichi Ichinose 4-640 Shimourado, Kiyose-shi, Tokyo Obayashi Technical Research Institute, Inc. (72) Inventor Yasuhiko Kunihara 4-640 Shimourado, Kiyose-shi, Tokyo Obayashi Technical Research Co., Ltd. In-house

Claims (6)

[Claims] 1. An oblique mesh shape in which concrete warp yarns and weft yarns made of reinforcing fibers cross at different positions and are joined to each other at a crossing angle θ of 90 ° <θ ≦ 170 °. A concrete structure in which the reinforcing material is embedded and short fibers of reinforcing fiber are mixed. 2. A plurality of warp yarns forming a warp yarn group extending at intervals in one direction and a plurality of weft yarns forming a weft yarn group extending at intervals in a direction intersecting the direction. The concrete structure according to claim 1, wherein the concrete structures are laminated at different positions and are sequentially stacked to intersect. 3. The concrete structure according to claim 1, which has a sheet shape or a three-dimensional shape. 4. The concrete structure according to claim 1, which contains 0.1 to 5% by volume of short fibers. 5. A method for producing a concrete structure, in which the diagonal mesh reinforcing material according to claim 1 is arranged in a mold, and mortar containing short fibers of reinforcing fibers is cast in the mold. 6. The method for manufacturing a concrete structure according to claim 5, wherein a diagonal mesh-shaped reinforcing material is embedded in the concrete with the acute angle portion of the intersection facing the direction of the stress acting on the structure.