JP2008013886A - Reinforcing fiber fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a reinforcing fiber fabric having excellent impregnation of thermosetting resin and improved repairing and reinforcing action. <P>SOLUTION: In the reinforcing fiber fabric, an area A in which warps and wefts are regularly crossed each other and areas B in which warps and wefts are not crossed each other and warps are floated exist in one layer of textile woven fabric, the circumferences of the areas B are enclosed by the area A and exists repeatedly in the warp direction and in the weft direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reinforcing fiber fabric suitable for an efficient repair or reinforcement method for concrete structures, steel structures, and wooden structures (hereinafter, they may be collectively referred to as “structures”).

  As a method of repairing or reinforcing conventional pillars, beams, and slabs of existing structures, a fiber sheet made of high-performance fibers such as carbon fiber and aramid fiber is bonded to the surface of the structure using a thermosetting resin. A method has been proposed. However, in this method, when a large amount of repair or reinforcement is required, a large number of thin fabrics are affixed or a few thick fabrics are affixed. In this case, the former is not satisfactory in terms of construction because it takes time to apply the thin fabric, and the latter is difficult to impregnate the thick fabric with the thermosetting resin.

  For this reason, Patent Document 1 describes a method in which a reinforcing fiber fabric is impregnated with a thermosetting resin in advance (hereinafter sometimes referred to as “preliminary impregnation”) and then attached to the surface of the structure. Has been.

However, in the method described in Patent Document 1, when a thick reinforcing fiber fabric is used, it is difficult to impregnate the fabric with a thermosetting resin substantially free of voids. In addition, in the thick reinforcing fiber fabric, the constituent yarn of the fabric becomes a thick yarn bundle, and there is a problem that the strength of the fiber is hardly expressed in the fabric due to the bending of the yarn bundle at the intersection.
Japanese Patent No. 3477118 (Claims)

  An object of the present invention is to provide a reinforcing fiber fabric that is excellent in impregnation with a thermosetting resin, can repair or reinforce a structure in a short time, has high strength, and has a good repair or reinforcement effect. .

  As a result of intensive studies to achieve the above object, the present inventors have found that in a reinforcing fiber fabric, a region A where warp yarns and weft yarns are regularly interlaced in one woven fabric, and warp yarns and weft yarns. By appropriately providing the region B in which the warp is not crossed and floated, the impregnation property of the resin can be improved and not only can be repaired or reinforced in a short time, but also the unexpected effect that the strength of the reinforcing fabric can be improved. The inventors have found that the above problems can be solved at once, and have completed the present invention.

That is, the present invention
[1] In the reinforcing fiber woven fabric, a region A where warp yarns and weft yarns are regularly crossed and a region B where warp yarns and weft yarns are not crossed and the warp yarns are floating exist in one woven fabric. The region B is surrounded by the region A and is repeatedly present in the warp direction and the weft direction.
[2] The reinforcing fiber woven fabric according to [1], wherein the region A is a flat, satin, twill or cocoon structure,
[3] The reinforcing textile fabric according to [1] or [2] above, wherein the length of one side of the region B is in the range of 10 to 90 mm,
[4] Any one of [1] to [3] above, wherein the pitch where the region B exists is in the range of 20 to 400 mm in the warp direction and in the range of 20 to 200 mm in the weft direction. The reinforcing fiber woven fabric according to
[5] The reinforcing fiber woven fabric according to any one of [1] to [4] above, wherein the total area ratio of the region B in the woven fabric area is in the range of 5 to 30%;
[6] The reinforcing fiber woven fabric according to any one of [1] to [5] above, wherein the basis weight of the woven fabric is in a range of 250 to 1500 g / m ² .
About.

According to the present invention, it is possible to provide a reinforcing fiber fabric that is excellent in resin impregnation and has a high strength expression rate even when the basis weight is high, and an efficient repair or reinforcement method can be realized. About the effect, the present inventors consider as follows.
(1) A regular woven fabric structure is formed as a whole of the woven fabric, and the presence of the region B at a predetermined interval allows air between the yarn bundles constituting the woven fabric and between single fibers in the yarn bundle. Since it is easy to deaerate through the area | region B, resin impregnation becomes easy.
(2) Since there is no bending between the warp and weft yarn bundles that intersect in the region B, the shear strength does not act on each fiber bundle and the single yarn constituting it when the fabric is pulled. Expressed in

  Hereinafter, the present invention will be described in detail with reference to the drawings as necessary. It should be noted that the drawings to be referred to are only for illustrating the present invention, and the present invention is not limited to those drawings.

  In the reinforcing fiber woven fabric of the present invention (hereinafter sometimes referred to as “woven fabric of the present invention”), a region A in which warp yarns and weft yarns are regularly crossed in one woven fabric, and warp yarns And a region B where the wefts are not interlaced and the warp is floating. The area B is surrounded by the area A and repeatedly exists in the longitudinal direction and the weft direction. In other words, in the woven fabric of the present invention, in a normal woven fabric structure where warps and wefts are regularly crossed, regions B where warps are floating in a certain area are arranged at regular intervals. It has a very characteristic configuration. This configuration is shown by, for example, FIG.

  As the texture form of the woven fabric in the region A, a flat, satin, twill or cocoon structure is preferable. In FIG. 1, the area A has a flat structure.

  The presence of the region A is essential in the configuration of the fabric of the present invention, and it is obvious that the fabric cannot be configured only by the region B. However, in the region A alone, there is a problem in resin impregnation, which is particularly remarkable in a fabric with a high basis weight.

  Generally speaking, a major factor that prevents the fabric from being impregnated with the resin is the presence of air between the yarn bundles constituting the fabric and in the yarn bundle. Therefore, when the resin is impregnated, the air is tried to be deaerated by applying a roller or the like. However, deaeration usually becomes more difficult as the number of single fibers in the yarn bundle constituting the fabric increases and the fabric structure becomes denser. For this reason, resin impregnation becomes difficult especially in fabrics with a high basis weight.

  Therefore, in the present invention, the region B is provided in order to facilitate deaeration without reducing the fabric weight.

  By providing this region B, not only resin impregnation is facilitated, but also the effect of improving the strength of the fabric can be obtained. The tensile strength of the woven fabric is maximum when there is no bending and the tension is uniformly distributed to each of the constituent fibers. However, in a normal woven fabric, the bending strength at the crossing point provides sufficient strength to match the strength of the constituent fibers. It is not obtained, that is, the expression rate of fabric strength is lowered. The decrease in the expression rate due to bending can be mitigated if the constituent fibers are easy to stretch, but generally speaking, the constituent fibers of the reinforcing fiber fabric have high strength and high elastic modulus, so there is little elongation. In particular, in the case of a high basis weight, an adverse effect of bending at the intersection is likely to occur. In the present invention, since the region B does not have an intersection point, the strength does not decrease due to bending, and as a result, it contributes to the improvement of the fabric strength.

  The shape of the region B is preferably rectangular, and the length of one side thereof is preferably in the range of 10 to 90 mm. The reason for setting the length of one side to 10 mm or more is to make the resin impregnation more reliable. However, if the length of one side is too long, the shape of the woven fabric tends to collapse. Therefore, the length of one side is preferably in the range of 90 mm or less.

As for the pitch where the region B exists, if the pitch is too large, the air far from the region B is difficult to escape and the resin impregnation property tends to decrease, and conversely if the pitch is too small, the morphological stability of the fabric tends to decrease. This is not preferable. Considering them, the pitch where the region B exists is preferably in the range of 20 to 400 mm in the warp direction, and preferably in the range of 20 to 200 mm in the weft direction.
Here, the pitch where the region B exists means, for example, the distance in the longitudinal direction between a point where one region B starts and a point where the next region B starts when viewed along the longitudinal direction. Thus, it does not mean the length of the region A between the point where one region B ends and the point where the next region B begins. For example, in the example shown in FIG. 2 and the example shown in FIG. 3, the pitch in the warp direction is 200 mm and the pitch in the weft direction is 100 mm. 2 and 3 are schematic diagrams for showing the arrangement of the region A and the region B and the like, not the fabric structure diagram.

The advantageous effect of the present invention described above is that the difference from the conventional fabric becomes more noticeable as the fabric weight increases, and the higher fabric weight can reduce the number of sheets used and save labor for repair or reinforcement. Therefore, the basis weight of the fabric of the present invention is preferably 250 g / m ² or more. On the other hand, if the fabric weight is excessively high, the impregnation property tends to be lowered even in the fabric of the present invention, and the fabric strength of the fabric tends to be lowered. More preferably, it is in the range of ˜1500 g / m ² .

  The fibers constituting the woven fabric of the present invention are carbon fibers, aramid fibers, PBO (polybaraphenylene benzoxazole) fibers, wholly aromatic polyester fibers, ultrahigh molecular weight polyethylene having a tensile strength of 16 cN / dtex or more as high-strength fibers. It is preferable that it is 1 type, or 2 or more types selected from the group which consists of glass fiber, polyester fiber, nylon fiber, and polyvinyl alcohol fiber as a general purpose fiber from fiber etc.

  The woven fabric of the present invention may be a unidirectional reinforcing fiber woven fabric in which high-strength fibers are arranged only in warps, or a bi-directional reinforcing fiber woven fabric in which high-strength fibers are arranged in warps and wefts.

  The warp fineness in the woven fabric of the present invention is preferably in the range of 900 to 16200 dtex. When the fineness of the warp is 900 dtex or less, the woven fabric becomes too thin, and the advantageous effects of the present invention described above are not preferable because the difference from the conventional woven fabric is reduced. On the other hand, if it exceeds 16200 dtex, the yarn bundle as the warp is too thick, and the rate of expression of the fabric strength tends to decrease due to bending at the intersection point. If necessary, a thread thinner than the fineness range may be supplementarily disposed on the warp.

  The fineness of the weft in the fabric of the present invention is preferably in the range of 180 to 16200 dtex. More specifically, when the woven fabric of the present invention is a unidirectional reinforcing fiber woven fabric, the weft yarn is exclusively intended to maintain the woven fabric form, and the fineness of the weft yarn is preferably in the range of 180 to 810 dtex. In addition, when the fabric of the present invention is a bi-directional reinforcing fiber fabric, the fineness of the weft yarn is preferably in the range of 900 to 16200 dtex, but if necessary, a yarn thinner than that range is supplementarily used as the weft yarn. You can arrange it.

  When the fabric of the present invention is used for repairing or reinforcing a structure, it is preferably used by impregnating a thermosetting resin. As the thermosetting resin, a room temperature curable thermosetting resin is mainly used, and examples thereof include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, and a methyl methacrylate resin.

  As a preferred embodiment of a method for repairing or reinforcing a structure using the fabric of the present invention, the surface of the structure is ground-treated in accordance with a conventional method, a primer is applied, a thermosetting resin is subbed, and the fabric of the present invention is applied. Then, after impregnating the resin, the same thermosetting resin is overcoated and further impregnated. In this process, it is preferable to promote deaeration by roller rolling or the like in order to satisfactorily impregnate the resin.

The amount of the thermosetting resin applied in the above method depends on the basis weight of the reinforcing fiber fabric. For example, when the basis weight is 500 g / m ² , as a guideline, the thermosetting resin of the undercoat applied to the structure surface is used. The amount is about 600 g / m ² , and after applying the reinforcing fiber fabric, the amount of the thermosetting resin applied is about 300 g / m ^{2, for} a total of about 900 g / m ² . When the reinforcing fiber fabric is a thick fabric with a higher basis weight, a pre-impregnation method in which the reinforcing fiber fabric is impregnated with a resin in advance may be used in combination.

  After the thermosetting resin impregnated in the reinforcing fiber fabric is cured by the above method, it is preferable to perform resin coating or mortar coating according to a conventional method in order to protect against external force and improve weather resistance. The structure repaired or reinforced as described above is excellent in mechanical strength and durability.

  The reinforcing fiber fabric of the present invention can be applied to, for example, columns, beams, slabs, walls, steel structure columns, beams, slabs, joints, joints of wooden structures, and the like of existing concrete structures. Needless to say, the present invention can also be applied to a new structure.

EXAMPLES The present invention will be specifically described below with reference to examples, but it goes without saying that the present invention is not limited to the following examples.
[Example 1] As a warp, a high elastic modulus aramid fiber having a fineness of 8000 dtex (6,000 filaments, strength 21 cN / dtex) ("Kevlar (registered trademark)" manufactured by Toray DuPont Co., Ltd., 26 pieces per 25 mm in the width direction, As a weft, 17 560 dtex (200 filaments) polyester fibers were supplied in a longitudinal direction of 25 mm, and a region A consisting of a plain structure, warp and weft, as shown in FIG. There is a region B where the warp yarns are not crossed and the region B is surrounded by the region A, and the region B is repeatedly present in the warp direction and the weft direction. The fabric weight was 850 g / m ² and the ratio of the area B to the total surface area was 11.26%.

[Comparative Example 1] A normal unidirectional reinforcing plain woven fabric having a width of 500 mm was woven in the same manner as in Example 1 except that the region B was not provided at all and the entire woven fabric had a plain structure.

[Example 2] As warp yarns, 13 high elastic modulus aramid fibers used in Example 1 per 25 mm in the width direction were supplied to a loom. As the weft, 13 high aramid fibers having the same elastic modulus as the warp are supplied per 25 mm in the longitudinal direction. As shown in FIG. 3, the region A composed of a flat structure, the warp and the weft are not mixed, and the warp is floating. Region B was present, and region B was surrounded by region A, and the bi-directional reinforcing fabric of the present invention having a width of 1000 mm, which was repeatedly present in the warp direction and the weft direction, was woven. The fabric weight was 850 g / m ² and the ratio of B to the total surface area was 10.6%.

 [Comparative Example 2] A normal bi-directional reinforcing plain fabric having a width of 1000 mm was woven in the same manner as in Example 2 except that the region B was not provided at all and the entire fabric had a plain structure.

The fabrics obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were impregnated with resin to produce FRP plates. As the resin, a room temperature curing epoxy resin (GB-35 manufactured by SRI Hybrid Co., Ltd.) was used. On the spread film, GB-35 was coated with an application amount of 800 g / m ² , a woven fabric was placed, and a rotating roller was used. After squeezing, the same resin was further overcoated at a coating amount of 400 g / m ² . Thereafter, the resin was cured by keeping it at room temperature for one week.
When the woven fabric was squeezed with a rotating roller, the time required for the resin undercoated to move to the surface of the woven fabric by capillary action was measured, and this was evaluated as the resin impregnation time.
A test piece was cut out from the FRP plate after the resin was cured in accordance with JIS Z 2201-13B, and a precision universal testing machine (“Autograph (registered trademark) AG-10TE” manufactured by Shimadzu Corporation) was used in accordance with JIS K 7073. The tensile strength test was conducted at a tensile speed of 2 mm / min.

  The measurement results are summarized in Table 1 below.

  It was confirmed that the resin impregnation property was improved by about 3 times compared to the comparative examples corresponding to Examples 1 and 2 respectively. In addition, there was no problem with the shape retention of the reinforcing fabric during resin impregnation, and the tensile strength was confirmed to be about 10% higher than the corresponding comparative examples in both Examples 1 and 2.

  If the reinforcing fiber fabric of the present invention is used, it can be used in a repairing or reinforcing method in which an excellent repairing or reinforcing effect can be easily obtained.

It is a textile organization chart which illustrates the organization of the textile fabric for reinforcement of the present invention. It is a plane schematic diagram which illustrates the form of the textile fabric for reinforcement of this invention. It is a plane schematic diagram which illustrates the form of the textile fabric for reinforcement of this invention.

Explanation of symbols

1: Area A
2: Area B
3: Reinforcing fiber fabric

Claims (6)

  In the reinforcing fiber woven fabric, a region A in which warp yarns and weft yarns are regularly crossed and a region B in which warp yarns and weft yarns are not crossed and the warp yarns float are present in one woven fabric. Is surrounded by a region A, and is present repeatedly in the warp direction and the weft direction.   2. The reinforcing fiber fabric according to claim 1, wherein the region A is a flat, satin, twill or cocoon structure.   The reinforcing fiber fabric according to claim 1 or 2, wherein a length of one side of the region B is in a range of 10 to 90 mm.   The reinforcing pitch according to any one of claims 1 to 3, wherein the pitch where the region B exists is in the range of 20 to 400 mm in the warp direction and in the range of 20 to 200 mm in the weft direction. Textile fabric.   5. The reinforcing fiber fabric according to claim 1, wherein the total area ratio of the region B in the fabric area is in the range of 5 to 30%. Reinforcing fiber fabric according to claim 1, the basis weight of the fabric, characterized in that in the range of 250~1500g / ^{m 2.}