JP3124829B2 - Manufacturing method of concrete reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a reinforcing material for concrete made of fiber reinforced plastic.

[0002]

2. Description of the Related Art Linear fiber reinforced plastics (hereinafter referred to as F
Attempts have been made to use RP rods (referred to as RP rods) as a reinforcing material for concrete, but the problem here is that the adhesion between the FRP rods and concrete is low. As a means for solving the problem, a. An uneven shape is formed on the surface of the FRP rod when the resin is cured. For example, JP-A-63-138052 (b) A thread is wound around the surface of an FRP rod and cured.
For example, in the construction of the FRP rod, a braided structure having an uneven surface is adopted. For example, JP-A-61-290
No. 150 has been proposed.

[0003]

However, all of these methods have the following problems and cannot be said to be satisfactory. That is, in the method a, the linearity of the reinforcing fibers cannot be maintained, so that the utilization rate of strength is low. In the method b, slip occurs due to shearing force between the wound yarn and the reinforcing fiber, and a sufficient adhesion effect cannot be obtained. In the method (c), the utilization of the strength and the elastic modulus is low as in the method (a), and irregularities large enough for the adhesion of concrete cannot be obtained. The present invention basically seeks to provide a reinforcement capable of withstanding higher shear forces in the structure shown in b above.

[0004]

According to the present invention, an uncured yarn impregnated with a thermosetting resin is wound around an outer periphery of an uncured reinforcing fiber yarn impregnated with a thermosetting resin. A method for producing a reinforcing material for concrete, characterized in that a plurality of filaments are drawn, twisted, and then heated to cure a thermosetting resin.

Hereinafter, the present invention will be described in detail. In the method of forming irregularities on the surface of the reinforcing fiber yarn by winding one or more yarns around the outer periphery of the reinforcing fiber yarn shown in the above-mentioned prior art b, the reinforcing fiber is wound. Adhesion with the attached yarn is caused only by the resin used, and the adhesive force is too low with respect to the stress generated in the reinforcing fiber yarn. As a result, the wound yarn and the reinforcing fiber Breakage occurs at the bonding portion of the yarn, and a phenomenon occurs in which the reinforcing fiber yarn comes off.

The present invention employs a special twisted structure to generate a pressure between a reinforcing fiber yarn and a yarn wound around the outer periphery thereof when stress is applied, whereby the reinforcing fiber is formed. The yarn and the wound yarn forming the convex portion are integrated to realize a structure in which the reinforcing fiber yarn hardly comes off.

The following is a detailed description with reference to the drawings. FIG.
In addition, the thermosetting resin used in the present invention is impregnated, and the uncured reinforcing fiber yarn (1) is wound around the outer periphery of the thermosetting resin-impregnated yarn (2). One example of the twisted body (3) in the stage is shown.

Such a structure is a known structure as disclosed in the prior art, for example, JP-A-63-138052. The structure shown in FIG. 1 is such that when a stress is generated in the reinforcing fiber yarn (1) as described above, the reinforcing fiber yarn (1) is easily separated from the wound yarn (2). I will fall out.

In the present invention, in the structure shown in FIG. 1, the reinforcing fiber yarn (1) is generally a fiber having high strength, and the properties of the yarn are not particularly limited. It is preferable to have a twist in the twist direction opposite to the winding direction of the yarn (2) wound around the outer periphery thereof.

[0010] Further, a yarn (2) forming a convex portion of the reinforcing material
Is a yarn having a diameter smaller than that of the reinforcing fiber yarn (1), but the number of windings, the thickness, the number of twists, and the direction of twist are not limited. As for the number of twists, the twist angle (the angle between the direction of the yarn and the fiber constituting the yarn) is preferably 15 ° or more. Suitable fibers that can be used in the present invention include carbon fibers, aramid fibers, glass fibers, and boron fibers.

In obtaining the first-stage twisted body (3) shown in FIG. 1, the reinforcing fiber yarn (1) and the yarn (2) wound around the outer periphery to form a convex portion are impregnated with resin. Prior to twisting or winding, a resin impregnation is performed to complete the process. As the resin used for the impregnation, a thermosetting resin is used. The type of the resin is not limited, but an epoxy resin, a maleimide resin, and a polyimide resin are suitable, and the resins used for the yarns (1) and (2) are preferably the same.

The first-stage twisted body (3) having the structure illustrated in FIG. 1 is then aligned and then twisted as a whole. At this time, it is necessary that the yarn (2) does not separate from the surface of the reinforcing fiber yarn (1), and this can be embodied by twisting under the following conditions. A. The winding direction of the yarn (2) with respect to the yarn (1) and the direction of the plurality of twisting twists should be matched. B If the winding direction of the yarn (2) does not match the direction of the plurality of twisting twists, or if there is an inconsistent winding direction, further twisting is performed in the winding direction. Alignment Twisting in the direction opposite to the twisting direction is performed.

One example of the reinforcing material thus obtained is illustrated in FIGS. FIG. 2 is a first-stage twisted body (3) shown in FIG.
3 shows a reinforcing material twisted under the condition of A, and FIG. 3 shows an appearance view of the reinforcing material twisted under the condition of B. However, FIG. Absent. The twisted body of the yarn shown in FIGS. 2 and 3 is then heated under the condition that the twisted body is given tension to cure the thermosetting resin.

[0014]

The advantage of the twisted body structure of the present invention is that the resin impregnated inside the yarn is squeezed out by twisting and tension, the surface becomes rich in resin, and the bond between the yarns (1) and (2) is strong. Can be performed. Further, when tensile stress is generated in the reinforcing material, a pressure toward the center of the reinforcing material is generated between the plurality of yarns (1), and this pressure is a pressure for pressing the yarn (2) against the yarn (1). Become
The connection between the yarns (1) and (2) is further strengthened. In particular, the structure shown in FIG. 3 has a large angle between the stress (the direction of the yarn (1)) generated in the reinforcing material and the direction of forming the convex portion (the direction of the yarn (2)). Great adhesion effect.

[0015]

The present invention will be further described below with reference to examples. Example 1 Ten carbon fiber tows in which about 12,000 carbon fibers having a diameter of 7 to 8 μ were bundled were bundled, and an epoxy resin having a resin content of 3 was used.
It was impregnated to 5%. This yarn has sufficient flexibility for twisting.
Twisting was performed 10 times in the direction to obtain the yarn (1) in FIG.

Separately, three carbon fiber tows are bundled, similarly impregnated with a resin, and then twisted in the Z direction so that the twist angle becomes 25 °, thereby producing a yarn (2) shown in FIG. Then, the yarn (2) is wound around the outer periphery of the yarn (1) at a winding pitch of 80 times per meter in the Z direction to obtain a first-stage twisted body (3) having the appearance shown in FIG. Was. Next, three twisted bodies (3) in the first stage were aligned and twisted 10 times per meter in the Z direction to obtain a twisted body having the appearance shown in FIG.
The twisted body was subjected to a heat treatment at 130 ° C. for 30 minutes to cure the thermosetting resin while applying a tension of 10 kg. As a result, the thermosetting resin was squeezed out to the surface of each yarn by the applied tension and the twist applied to the yarn to obtain a reinforcing material in which the yarns (1) and (2) were firmly fixed. .

Example 2 In the same manner as in Example 1, yarns (1) and (2) were obtained. However, in this embodiment, the yarn (2) is wound around the outer periphery of the yarn (1) at a pitch of 80 times per meter in the S direction, and the yarn is twisted 10 times per meter in the S direction. A first-stage twisted body (3) was obtained. Next, three twisted bodies (3) are aligned and twisted 10 times per meter in the Z direction to obtain a twisted body having the appearance shown in FIG. The same heat treatment as in Example 1 was performed to obtain a reinforcing material. Also in this reinforcing material, the yarns (1) and (2) were firmly fixed and the resin was sufficiently squeezed out, so that the reinforcing material was satisfactory.

[0018]

According to the concrete reinforcing material obtained by the present invention, the yarn (2) forming the convex portion and the reinforcing fiber yarn (1) are firmly connected to each other, and the resistance of the yarn (1) to pull-out is reduced. However, there is an advantage that it greatly improves.

[Brief description of the drawings]

FIG. 1 is an external view of a first-stage twisted body structure for obtaining a reinforcing material of the present invention.

FIG. 2 is an external view when a plurality of first-stage twisted bodies are aligned and twisted as a whole.

FIG. 3 is an external view of another example when a plurality of first-stage twisted bodies are aligned and twisted as a whole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforcing fiber yarn 2 Yarn for forming a convex part 3 First-stage twisted body

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Setsuo Kashiyama 4-160 Sunadabashi, Higashi-ku, Nagoya-shi, Aichi Mitsubishi Rayon Co., Ltd. Product Development Laboratory (58) Field surveyed (Int. Cl. ⁷ , DB name) ) B28B 23/02 D02G 3/44 D07B 1/16

Claims (1)

(57) [Claims] An uncured reinforcing fiber yarn impregnated with a thermosetting resin is wound around an uncured yarn impregnated with a thermosetting resin. A method for producing a reinforcing material for concrete, comprising curing a thermosetting resin after uniform twisting.