JP3748435B2 - Fiber sheet for welding reinforcement - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reinforcing fiber sheet for reinforcing members, and more particularly, to a general building structure such as a building column, beam, slab, wall, pier, bridge girder, floor slab, and tunnel lining. The present invention relates to a reinforcing fiber sheet used as a reinforcing material for the like.
[0002]
[Prior art]
Usually, since a building structure is in a state of receiving various external forces, impacts, vibrations, etc., strict structural design (seismic design, strength design, etc.) is made in accordance with building standards.
However, it has been revealed that building structures (for example, piers on expressways, etc.) are surprisingly inferior in strength due to the collapse of the earthquake due to the Great Hanshin Earthquake.
This is because there is a problem in the strength reduction of the material (for example, concrete etc.) in addition to the structural design of the building structure.
[0003]
For this reason, a countermeasure to reinforce the building structure and improve the strength is required.
However, it is difficult from the technical and cost standpoints to reconstruct the structure of a building structure that has already been made or to change its material.
Therefore, at the present time, in order to reinforce a building structure that has already been constructed (for example, a pillar of a building, a highway pier, etc.), a method of attaching a steel plate as a reinforcing material around the structure is often employed.
However, since steel plates are heavy and take time to carry in, and there are drawbacks such as the need for welding, etc., instead of steel plates, reinforcing fiber sheets are bonded around the members to be reinforced. A method of pasting and fixing by, for example, was developed.
[0004]
As this method, for example, there is a method of reinforcing a structure as shown in Patent Document 1.
This method is a method in which reinforcing fibers are bonded and reinforced with a unidirectionally arranged reinforcing fiber sheet in which reinforcing fibers are arranged and bonded in both directions on both sides of a support sheet, and it is generally said that construction efficiency is good.
To attach to the surface of the structure, it is important that the support sheet is as flexible as possible from the viewpoint of workability. However, since the support sheet is in the form of a cloth or a film, the sheet as a whole is not so flexible. Inferiority is a drawback.
As another method, for example, there is a method of reinforcing a structure as shown in Patent Document 2.
[0005]
In this method, the aramid reinforcing fiber group is regarded as a unit, and the aramid reinforcing fibers are arranged in a cage shape at intervals, and this cage-like fiber group is bundled with the reinforcing fiber, and is entangled with the warp knitting structure between the ribs. It is a fiber sheet.
The aramid reinforcing fiber sheet is reinforced by adhering it to the object to be reinforced.
This method is more flexible than the former method, but because of the entanglement between the ribs, the thickness of this portion is increased, and a satisfactory flexibility cannot always be obtained.
Moreover, since it has an entangled portion, there is a disadvantage that the thickness of the entire sheet can be uneven.
[0006]
Furthermore, as another method, for example, there is a base fabric for reinforcing a composite molded body as shown in Patent Document 3.
This is a multifilament untwisted or sweet twisted yarn with high strength, high rigidity and high elastic modulus as a warp, a sweet twisted yarn or untwisted yarn containing an adhesive as a weft, and a number of arranged warp yarns are stacked on one side, It is a composite molded body reinforcing base fabric obtained by bonding the two at the intersection, and is used as a composite.
However, in the weft, depending on the state of the adhesive applied, the multifilament warp may have unevenness due to the different adhesive strength, and in the extreme, there will be a portion where no adhesive is applied, and that portion cannot be bonded to the warp. Furthermore, when manufacturing, there is a difficulty in that an additional step of applying an adhesive to the weft is necessary.
[0007]
[Patent Document 1]
Japanese Patent No. 2819333 [Patent Document 2]
JP-A-10-102364 [Patent Document 3]
JP 59-83619 A
[Problems to be solved by the invention]
The present invention has been made in order to overcome the above-mentioned problems against the background of such circumstances.
That is, an object of the present invention is to provide a reinforcing fiber sheet that has as little thickness unevenness as possible, excellent flexibility, and excellent workability, and a method for manufacturing the same.
[0009]
[Means for Solving the Problems]
Thus, as a result of intensive research on the background of such problems, the present inventor has found that the reinforcing fiber yarn bonded to the object to be reinforced is not bonded to the surface even when the fiber bundle is not bound. It was found that there is no problem in workability if it is held from both sides to such an extent that it does not float up, and the present invention has been completed based on this finding.
[0010]
That is, the present invention is (1) a single sheet having a heat-welding property in a direction different from the bundle sheet on both sides of the bundle sheet with respect to a bundle sheet formed by arranging a large number of reinforcing fiber yarns in one direction. To reinforce by sticking to the peripheral surface of a building structure characterized in that a weft of a single material that melts entirely at temperature is pressure welded, the weft is crushed in the radial direction, and a bundle sheet is held together It exists in the reinforcing fiber sheet.
[0011]
And (2), the different direction exists in the reinforcing fiber sheet that is perpendicular to the bundle sheet.
[0012]
And (3), the different direction exists in the fiber sheet for reinforcement which is a direction inclined with respect to the bundle sheet.
[0013]
And (4), each weft on both sides of the front and back is inclined, and exists in the reinforcing fiber sheet having the same inclination as viewed from one side.
[0014]
And (5), each weft of the front and back both sides is inclined, and exists in the reinforcing fiber sheet having a different inclination when viewed from one side.
[0015]
And (6), the wefts on both sides of the front and back are inclined, the inclination is different on the front side and the back side as seen from one side, and the wefts cross on the front side and the back side. It exists in the reinforcing fiber sheet.
[0016]
And (7) exists in the reinforcing fiber sheet in which the pitch intervals of the respective wefts on the front and back side surfaces are different between the front side surface and the back side surface.
[0017]
And (8) exists in the reinforcing fiber sheet in which the pitch interval of the respective wefts on the front and back side surfaces is the same on the front side surface and the back side surface.
[0018]
And (9) exists in the reinforcing fiber sheet whose reinforcing fiber yarn is aramid fiber or carbon fiber.
[0019]
Further, (10), the reinforcing fiber sheet in which the weft is a polyamide fiber, a polyester fiber, a polyacrylonitrile fiber, a polyvinyl alcohol fiber, a polyvinyl chloride fiber, a polyolefin fiber, or a polyurethane fiber. Exist.
[0020]
The present invention may employ a configuration in which two or more selected from the above 1 to 10 are combined as long as it meets this purpose.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
This reinforcing fiber sheet is useful for reinforcing general building structures such as building columns, beams, slabs, walls, piers, bridge girders, floor slabs, tunnel linings, etc. .
In particular, it is often performed to attach and reinforce the peripheral surfaces of these building structures.
[0022]
[First Embodiment]
FIG. 1 is an enlarged schematic view of a reinforcing fiber sheet according to an embodiment of the present invention, (A) shows a plan view thereof, and (B) shows a side view thereof.
The reinforcing fiber sheet A is based on a bundle sheet 1 in which a large number of reinforcing fiber yarns 1A arranged in one direction are collected.
Furthermore, the reinforcing fiber yarn 1A is composed of a large number of fibers (several hundreds to thousands).
The thickness (fineness) of the reinforcing fiber yarn 1A is usually 1000 to 30000 dT (decitex), and untwisted yarn or sweet twisted yarn is used.
As a material of the reinforcing fiber yarn 1A, for example, carbon fiber, aramid fiber or the like is used.
[0023]
As the basis weight of the bundle sheet 1, for example, about 100 to 800 g / m ² is adopted.
Weft yarns 2 and 3 are welded to both the front and back side surfaces of the bundle sheet 1 in a direction different from the length direction of the bundle sheet 1 to form a reinforcing fiber sheet.
In such a reinforcing fiber sheet A, weft yarns 2 and 3 are attached so as to grip a bundle sheet 1 made of a plurality of reinforcing fiber yarns 1A from both side surfaces (that is, the front side surface and the back side surface). Because of the arrangement, the entire bundle sheet is accurately held as a unit.
[0024]
In this embodiment, the wefts 2 and 3 are arranged in a direction perpendicular to the direction of the bundle sheet 1, and the weft 2 welded to the front side and the weft 3 welded to the back side are Are arranged at the same interval (pitch) P.
The interval (pitch) P is arranged in a so-called rough state, for example, 5 mm, 10 mm, 15 mm, or the like.
When viewed from one direction, they do not overlap at the same position (FIG. 1 shows that the wefts on the front side surface and the back side surface are shifted by a half pitch, respectively).
As the wefts 2 and 3, those having the property of being able to be heated and welded to the bundle sheet (that is, heat weldability) are used.
[0025]
For example, polyamide fiber, polyester fiber, polyacrylonitrile fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, polyolefin fiber, polyurethane fiber, or the like is used.
As the wefts 2 and 3, spun yarn, monofilament yarn, or multifilament yarn is used.
[0027]
Next, a method for producing the reinforcing fiber sheet in this way will be described.
FIG. 2 is a view schematically showing a method for producing a reinforcing fiber sheet.
First, in advance, the reinforcing fiber yarns 1A are grouped into a certain number (for example, about several hundreds) to form an independent bundle of fiber bundles X.
In a state where a plurality of bundles, for example, 20 bundles, are bundled in the horizontal direction to form a bundle sheet 1, the bundle bundle 1 is supplied at a constant speed in the length direction of the bundle sheet 1.
However, after forming the fiber bundle X in this way, it is possible to form the bundle sheet 1 by arranging a large number of reinforcing fiber yarns 1A in the horizontal direction without being formed on the bundle sheet 1.
[0028]
The weft yarn 2 is supplied to the feeding and moving bundle sheet 1 in the direction perpendicular to the direction of the bundle sheet 1 on the front and back sides.
Here, the weft 2 has the property of being melted and welded to the bundle sheet by applying heat as described above.
When the weft is supplied, the movement of the bundle sheet 1 is temporarily stopped, and the weft is attached in the perpendicular direction in this state.
[0029]
In this case, specifically, for example, the yarn feeder K for supplying the weft yarn 2 is moved in a direction perpendicular to the length direction of the bundle sheet 1 so as to cross the bundle sheet 1 and is suspended on the bundle sheet 1. Thus, the weft 2 is attached on the bundle sheet 1.
As will be described later, if the bundle sheet 1 is not stopped when the weft 2 is supplied, the weft 2 coming out of the yarn feeder K will be attached in a direction inclined with respect to the direction of the bundle sheet 1. (See FIG. 4).
Of course, although not shown, it is of course possible to attach the weft 2 in the perpendicular direction by moving the weft 2 at the same speed as the movement speed of the bundle sheet 1 and moving across the bundle sheet 1. is there.
[0030]
Now, the weft 2 attached on the bundle sheet 1 must be welded to the bundle sheet.
Therefore, this time, the bundle sheet 1 with the weft 2 attached is heated to melt the weft 2.
In that case, specifically, as shown in FIG. 2, it is preferable to pass the bundle sheet 1 between a pair of rotating heating rollers R and press the wefts against the bundle sheet.
[0031]
In this way, the weft is pressure-welded to the surface of the bundle sheet by receiving heat and pressure.
In this case, the weft yarn that has been heated and pressured by the roller is crushed in the radial direction, so that the press contact area becomes large and is securely fixed to the bundle sheet, and the thickness of the weft portion is not conspicuous.
[0032]
After the weft 2 has been pressure welded to the front side of the bundle sheet 1, the weft 3 is then attached to the back side of the bundle sheet 1 in this manner (in this case, the bundle sheet 1 is turned over in a separate step). In the same manner, the weft thread 2 is hung down and attached).
Then, the bundle sheet with the weft yarn 2 attached is heated, and the weft yarn 2 is melted and pressed as described above to press-weld it onto the bundle sheet.
By this way, the weft yarn 2 and 3 to be pressed against the welding on both sides of the bundle sheet 1 (i.e. front back sides of the bundle sheet 1), the bundle sheet 1 is held together without being Barabbas et al .
[0033]
In this reinforcing fiber sheet A, since the weft yarns 2 and 3 are welded along the surface of the bundle sheet 1 (consisting of a large number of fiber yarns), the weft yarns 2 and 3 are always in a straight state (that is, in the vertical direction). There is no entanglement with other yarns.
In addition, since the wefts 2 and 3 are arranged on both the front and back sides of the bundle sheet 1, the reinforcing fiber yarn 1A constituting the bundle sheet 1 is accurately held, unlike the conventional sheet described above.
[0034]
Further, since the wefts 2 and 3 are welded at intervals as described above, they are in a so-called rough state, and the entire reinforcing fiber sheet is relatively thin and excellent in flexibility. .
Further, in particular, the fiber bundles in the bundle sheet are not entangled by the auxiliary yarn as in the prior art, and the weft yarns 2 and 3 are connected so as to extend substantially straight. A degree of freedom of movement occurs in a part of 1A, which contributes to an improvement in flexibility as the entire reinforcing fiber sheet.
[0035]
When the reinforcing fiber sheet A of this embodiment is actually applied on site, the corner surface of the object to be reinforced can be made to fit precisely because of flexibility, and the wefts 2 and 3 are in a rough state. Therefore, the resin material (adhesive) can easily penetrate into the bundle sheet.
In this embodiment, the example of the welding of the weft to the bundle sheet is shown by the pressure welding by the heating roller, but it is not always necessary to use this means.
For example, a heating method using light rays such as infrared rays can naturally be employed.
A method of induction heating a weft containing a conductive material such as iron powder is also possible.
[0036]
[Second Embodiment]
FIG. 3 is an enlarged schematic view of a reinforcing fiber sheet according to an embodiment of the present invention, in which (A) shows a plan view thereof and (B) shows a side view thereof.
Also in this case, as in the first embodiment described above, the fibers that contribute to the reinforcement of the reinforcing fiber sheet A are the reinforcing fiber yarns 1A arranged in one direction, and such reinforcing fiber yarns. A bundle sheet 1 as a base is formed by collecting a large number of 1A.
And the weft yarns 2 and 3 are welded to the front and back both side surfaces of such a bundle sheet 1 in a direction different from the direction of the bundle sheet 1 to form a reinforcing fiber sheet.
[0037]
This embodiment differs from the first embodiment in that, in the first embodiment, the wefts 2 and 3 are perpendicular to the length direction (arrangement direction) of the bundle sheets 1. In this embodiment, the wefts 2 and 3 have a constant inclination angle (θ) with respect to the direction perpendicular to the length direction (arrangement direction) of the bundle sheet 1.
That is, the wefts 2 and 3 are welded to the bundle sheet 1 in a rough state with a certain distance and interval at an inclination angle θ.
The inclination angle θ1 of the weft 2 on the front side and the inclination angle θ2 of the weft 3 on the back side are the same, and are parallel when viewed from one side, and the wefts 2 and 3 do not intersect.
[0038]
FIG. 4 is a diagram schematically showing a method for manufacturing such a reinforcing fiber sheet.
In order to manufacture the reinforcing fiber sheet A, for example, the yarn feeder K of the weft 2 may be moved in a direction perpendicular to the moving direction while the bundle sheet 1 is moved.
Alternatively, the bundle sheet 1 may be moved at a constant inclination angle with respect to the direction perpendicular to the length direction in a state where the movement of the bundle sheet 1 is stopped.
The inclination angle θ can be adjusted and set to a free size by the moving speed of the bundle sheet and the weft.
In addition, as described above, the welding of the weft 2 to the bundle sheet 1 is, for example, a method in which the bundle sheet 1 and the wefts 2 and 3 are pressure-bonded using a heating roller or the like.
[0039]
[Third Embodiment]
FIG. 5 is an enlarged schematic view of a reinforcing fiber sheet according to an embodiment of the present invention, in which (A) shows a plan view thereof and (B) shows a side view thereof.
Also in this case, as in the second embodiment described above, the fibers that contribute to the reinforcement of the reinforcing fiber sheet A are the reinforcing fiber yarns 1A arranged in one direction, and such reinforcing fiber yarns. A large number of 1A are gathered to form a bundle sheet 1 as a base.
[0040]
This embodiment differs from the second embodiment in that, in the second embodiment, the wefts 2 and 3 on both the back side surface and the front side surface are in the length direction (arrangement direction) of the bundle sheet 1. And the same constant inclination angle (θ1 = θ2) with respect to the right angle direction, and different inclination angles θ1 (front side surface) and inclination angle θ2 (back side surface) (θ1 = −θ2).
When viewed from one side, the weft 2 on the front side and the weft 3 on the back side have an intersection J.
[0041]
[Fourth Embodiment]
FIG. 6 shows a fourth embodiment.
In this embodiment, the interval (ie, pitch) P1 between the wefts 2 on the front side surface and the interval P2 between the wefts 3 on the back side surface in the first embodiment are different (P1 ≠ P2).
[0042]
[Fifth Embodiment]
FIG. 7 shows a fifth embodiment.
In this embodiment, the inclination angle θ1 of the weft 2 on the front side and the inclination angle θ2 of the weft 3 on the back side in the second embodiment are different.
However, when the wefts 2 and 3 on both sides are viewed from one side, there is no intersection J as shown in FIG.
[0043]
[Sixth Embodiment]
FIG. 8 shows a sixth embodiment.
In this embodiment, the inclination angle θ1 of the weft 2 on the front side and the inclination angle θ2 of the weft 3 on the back side in the third embodiment are different.
When viewed from one side, the weft 2 on the front side and the weft 3 on the back side have an intersection J.
[0044]
[Seventh embodiment]
FIG. 9 shows a seventh embodiment.
In this embodiment, only the weft 2 on the front side in the third embodiment has an inclination angle θ1 of zero (perpendicular to the length direction of the bundle sheet).
The manufacturing method can be performed by combining the manufacturing methods of the first embodiment and the third embodiment.
[0045]
[Other embodiments]
In addition to the above, in the second, third, fifth, sixth, and seventh embodiments, the interval (pitch) P between the wefts 2 and 3 can be changed.
[0046]
Next, a reference example using a reinforcing fiber sheet is shown.
[0047]
[ Reference Example 1 ]
Carbon fiber UT-500 (24K) [16000 Tex] manufactured by Toho Tenax Co., Ltd. was used as the reinforcing fiber yarn (1K = 1000).
The reinforcing fiber yarn was formed into a bundle sheet with a width of 50 cm so as to have a basis weight of 300 g / m ² .
On this bundle sheet, a conjugate yarn 190dT (decitex) -30f (filament) manufactured by Mitsubishi Rayon Co., Ltd. is used as a heat-welding fiber for the weft yarn on both sides of the front and back surfaces at 10 mm intervals so as to be perpendicular to the direction of the bundle sheet. Arranged.
[0048]
The weft was shifted by a half pitch between the front side and the back side (see FIG. 1).
The conjugate yarn (polyolefin yarn) has a core portion: polypropylene and a sheath portion: polyethylene (weight ratio is 50/50).
The bundle sheet on which the wefts were arranged was moved at a speed of 5 m / min, and was welded by overheat pressing with a 130 ° C. heating roller to obtain a reinforcing fiber sheet.
[0049]
Next, with respect to the reinforcing fiber sheet, the Maeda Ko繊Co. epoxy resin FF dynes D70 undercoat (0.4 Kg / m ² solid) and overcoated (0.2 Kg / m ² coating), this, Reinforced by pasting to the surrounding surface of a concrete pillar with a square cross section. In addition, 0.2 kg / m ^{2 of an} epoxy resin FF primer P10 manufactured by Maeda Kosen Co., Ltd. was previously applied to the concrete surface for adhesion enhancement.
After the construction, 24 hours later, the reinforced finished surface of the concrete column was observed.
[0050]
[ Reference Example 2 ]
The weft conjugated yarns were tilted by 60 degrees with respect to the direction of the bundle sheet (that is, the tilt angle θ: 30 degrees) and arranged at intervals of 10 mm (pitch).
In this case, the weft was in the direction where the front side surface and the back side surface intersect (see FIG. 5).
In addition, the bundle sheet, the weft, and the welding method were the same as in Reference Example 1 to obtain a reinforcing fiber sheet.
Next, this welded reinforcing fiber sheet was applied and reinforced by applying the same method as in Reference Example 1 around a concrete column having a square cross section.
Similarly, 24 hours after construction, the finished surface of the reinforced concrete column was observed.
[0051]
【result】
Evaluation at the time of construction and after construction in the case of Reference Example 1 and Reference Example 2 are as follows.
1) Since the yarns for restraining the bundle sheet are arranged in a rough state in the weft direction (10 mm interval in the reference example ), it has excellent flexibility and is easy to construct.
In particular, it was possible to attach the corner of a rectangular concrete column very easily.
2) It has good resin impregnation properties and can be fixed in close contact with the concrete surface.
3) Since the yarn that binds the bundle sheet is crushed by the overheat pressure bonding, the thickness is not uneven and the finished surface is clean.
[0052]
Although the present invention has been described above, the present invention is not limited to the embodiments as long as the object is met, and various modifications are possible.
For example, even if the fiber for reinforcement is other fiber such as carbon fiber or aramid fiber, it is sufficient as long as the purpose is met.
[0053]
Further, the manufacturing method can be adopted other than those shown in the embodiment.
In addition, when wefts are welded to a bundle sheet, methods other than the method using a heating roll can naturally be applied to embodiments other than the first embodiment.
[0054]
【The invention's effect】
For a bundle sheet in which a large number of reinforcing fiber yarns are arranged in one direction, a bundle sheet in which wefts are welded in a direction different from the direction of the bundle sheet is integrally held on both front and back sides of the bundle sheet. As a reinforcing fiber sheet, it becomes excellent in flexibility.
[0055]
Moreover, since there is no front and back, work can be performed efficiently in construction.
Moreover, when manufacturing the fiber sheet for reinforcement, since there is no application | coating process of an adhesive agent, there may be few manufacturing steps.
And the resin agent used in order to harden at the time of construction can be easily osmose | permeated with respect to a bundle sheet | seat, and the high quality on construction is guaranteed.
In addition, when the weft is welded to the bundle sheet by thermocompression bonding, the weft is firmly fixed to the bundle sheet, and the thickness of the reinforcing fiber sheet is hardly noticeable.
[Brief description of the drawings]
FIG. 1 is an enlarged schematic view of a reinforcing fiber sheet according to a first embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
FIG. 2 is a diagram schematically showing a method for manufacturing the reinforcing fiber sheet of the first embodiment.
FIG. 3 is an enlarged schematic view of a reinforcing fiber sheet according to a second embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
FIG. 4 is a diagram schematically illustrating a method for manufacturing a reinforcing fiber sheet according to a second embodiment.
FIG. 5 is an enlarged schematic view of a reinforcing fiber sheet according to a third embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
FIG. 6 is an enlarged schematic view of a reinforcing fiber sheet according to a fourth embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
FIG. 7 is an enlarged schematic view of a reinforcing fiber sheet according to a fifth embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
FIG. 8 is an enlarged schematic view of a reinforcing fiber sheet according to a sixth embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
FIG. 9 is an enlarged schematic view of a reinforcing fiber sheet according to a seventh embodiment of the present invention, (A) is a plan view thereof, and (B) is a side view. .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Bundle sheet 1A ... Reinforcement fiber yarn 2 ... Weft (table)
3 ... Weft (back)
P ... Interval (pitch)
A ... Reinforcing fiber sheet J ... Intersection K ... Yarn feeder R ... Heating roller X ... Fiber bundle

Claims (10)

For a bundle sheet formed by arranging a large number of reinforcing fiber yarns in one direction, a single unit having a heat-welding property that melts entirely at a single temperature in different directions from the bundle sheet on both sides of the bundle sheet. A reinforcing fiber sheet for press-welding a weft of a material, and crushing the weft in a radial direction to hold a bundle sheet integrally to reinforce by sticking to a peripheral surface of a building structure.   The reinforcing fiber sheet according to claim 1, wherein the different direction is a direction perpendicular to the bundle sheet.   The reinforcing fiber sheet according to claim 1, wherein the different direction is a direction inclined with respect to the bundle sheet.   2. The reinforcing fiber sheet according to claim 1, wherein the wefts on both sides of the front and back sides are inclined and have the same inclination as viewed from one side.   2. The reinforcing fiber sheet according to claim 1, wherein the wefts on both front and back sides are inclined and have different inclinations when viewed from one side.   The wefts on both sides of the front and back sides are inclined, have different degrees of inclination on the front side and the back side as viewed from one side, and the wefts intersect on the front and back sides. The reinforcing fiber sheet as described.   The reinforcing fiber sheet according to claim 1, wherein the pitch interval between the wefts on the front and back side surfaces is different between the front side surface and the back side surface.   The reinforcing fiber sheet according to claim 1, wherein the pitch interval between the wefts on both side surfaces is the same on the front and back sides.   The reinforcing fiber sheet according to claim 1, wherein the reinforcing fiber yarn is an aramid fiber or a carbon fiber.   2. The reinforcing yarn according to claim 1, wherein the weft is a polyamide fiber, a polyester fiber, a polyacrylonitrile fiber, a polyvinyl alcohol fiber, a polyvinyl chloride fiber, a polyolefin fiber, or a polyurethane fiber. Fiber sheet.

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