JPH06155443A - Fiber reinforced resin large diameter deformed rod and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide large diameter FRP rod, which is used for reinforcing concrete, excellent in fixing properties in the concrete and the adhesion between the rod and the concrete and especially excellent as earth anchor. CONSTITUTION:In rod 1, in which a fiber bundle made of high strength organic synthetic fibers paralleled to one direction is impregnated with resin and hardened, the mean outer diameter of the rod 1 is 18mm or larger and projecting parts, each of which is made of resin and extends to the direction intersecting with the longitudinal direction of the rod 1, are characteristically formed on the outer periphery of the rod in order to produce the fiber reinforced resin deformed rod concerned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-diameter deformed rod for reinforcing material, which is suitable for the field of civil engineering and construction, which is composed of a resin reinforced with organic synthetic fibers.

[0002]

2. Description of the Related Art In the field of civil engineering and construction, deformed bar is often used as a reinforcing material for concrete. Although deformed bar has high strength and elastic modulus, it is difficult to handle because it is heavy, and safety and labor are important points. Hated by Further, as a major drawback of the deformed bar, when it is used as a reinforcing material for an electric orbital subgrade or the like in which electricity is generated, by contact with water containing an acid, an alkali, salt, etc., an earth mass, etc., There is a drawback in terms of durability that rust is generated due to the formation of the electrode battery, cracking of concrete is caused, and reinforcing property of the reinforcing bar is lost. In order to solve the drawbacks of the reinforcing bars, a so-called fiber-reinforced resin (hereinafter referred to as FRP) rod made by pull-out molding, in which various kinds of organic synthetic fibers are used and solidified and integrated with resin, has been developed.
However, in the pultrusion molding method, the average diameter is 18 mm or more, especially 20 mm or more, because uniform curing cannot be performed, curing time is long and it is difficult to manufacture, fixing on concrete, etc. It is difficult to make things.

[0003]

As a method of manufacturing a rod having a large diameter, a method of bundling a plurality of rods having a small diameter, a method of twisting a plurality of rods having a small diameter, and the like are known. However, the large-diameter rods obtained by using these methods have been solved regarding the problems of rust and heavyness that are the drawbacks of reinforcing bars, but at the terminal fixing part when used for reinforcement of concrete, earth anchors, etc. Since the adhesive strength and fixing strength with concrete are insufficient,
The original effect of reinforcement cannot be achieved. The main reason for this is that in the above method, in general, in order to secure the adhesive force, a small diameter rod is wound around the surface of the large diameter rod by oblique winding or the like, and a convex portion by the small diameter rod is formed on the surface of the large diameter rod. However, there is a lack of integration of the slenderly wound small diameter rod and the rod body, and the effect of having the convex portion is not sufficiently exerted. Especially when the diameter is large, the oblique winding portion is easily peeled off from the rod body, and it is more important to solve this problem.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve this problem and provides a rod having a large diameter which is excellent in the adhesive strength and anchoring strength of concrete and has an extremely large reinforcing effect. . That is, the present invention is an FRP rod in which a resin is impregnated and cured in a fiber bundle in which organic synthetic fibers are aligned in one direction, and the average outer diameter of the rod is 18 mm or more, preferably 20 mm or more, Further, a deformed rod made of FRP, characterized in that a convex portion made of the resin and extending in a direction intersecting the length direction of the rod is formed on the outer periphery of the rod, and the present invention also provides an organic synthetic fiber. In the method for producing a deformed rod made of FRP, wherein a fiber bundle having a thickness of 800,000 denier or more, and preferably 1,000,000 denier or more is aligned, and a fiber bundle impregnated with a curable uncured resin is put into a mold and molded and cured. The mold is a mold having a groove having an average diameter of 18 mm or more, preferably 20 mm or more, in which the fiber bundle is inserted, and a recess extending on a surface of the groove in a direction intersecting a length direction of the groove. It is a manufacturing method of the FRP profiled rods, characterized in.

That is, the present invention relates to a large diameter F made of organic synthetic fiber.
The average diameter of the RP rod (the diameter of the circle corresponding to the cross-sectional area when the rod is not circular in cross section) is 18 mm or more,
Preferably, a large number of organic synthetic fibers are aligned so as to have a size of 20 mm or more, and synthetic resin is impregnated therein, or an average diameter is 18 while impregnating a large number of organic synthetic fibers with resin.
It is obtained by putting the fiber bundle obtained by pulling and aligning the fiber bundle to have a size of not less than 20 mm, preferably not less than 20 mm, into a mold having the above-mentioned irregular shape, curing the resin, and releasing the mold. Hereinafter, the present invention will be described in detail.

The organic synthetic fibers used include polyvinyl alcohol fibers, wholly aromatic polyester fibers (so-called arylate fibers), wholly aromatic polyamide fibers (so-called aramid fibers), polyacrylonitrile fibers, and polyolefin fibers. And the like, and the strength thereof is preferably 7 g / d or more, particularly preferably 12 g / d or more. Of course, two or more kinds of fibers can be used together.
For example, by using fibers with high strength as the fibers forming the outer layer of the rod and fibers with relatively low strength as the fibers forming the inner part, and by using fibers with excellent alkali resistance for the outer layer of the rod, compare the inside. By making the fiber inferior in alkaline resistance, a rod suitable for various purposes can be obtained. The thickness of the fiber is 1.0-
1500d is preferable in terms of bending strength, handleability, and the like when the assembly (rod) is formed. There are a beam stand method, a creel stand method and the like as a method for aligning fibers. And the thickness of the fiber bundle after being aligned is 80
It is required to be 10,000 d or more, preferably 1 million d or more.

Examples of the resin constituting the rod include thermosetting resins such as epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, melamine resins and urea resins. Of these, epoxy resins are preferable from the viewpoint of adhesiveness to fibers, strength, and the like.

As described above, a fiber bundle in which a large number of organic synthetic fibers are drawn and aligned is dipped and impregnated in a thermosetting resin liquid, and then excess resin is squeezed to obtain a thickness of 18 mm or more, preferably 20 mm or more. A rod-shaped resin-impregnated fiber bundle is obtained. The volume ratio of the resin in the resin-impregnated fiber bundle is preferably about 30 to 50%. The reason is that the strength of the fiber as a reinforcing material is exerted, and the tensile strength and Young's modulus of the composite material are increased as the amount of the resin as the matrix component is smaller than that of the composite rule using continuous fibers. As described above, the thickness of the fiber bundle is required to be 800,000 d or more, preferably 1 million d or more. It is usually difficult to uniformly impregnate the resin even inside the resin. Therefore, a resin-impregnated small-diameter fiber bundle obtained by immersing a thin fiber bundle in a resin liquid is bundled later to 800,000 d or more, preferably 100 A method of forming a large diameter fiber bundle of 10,000 d or more is preferable. By using this method, it is possible to easily manufacture a large-diameter fiber bundle in which the resin is evenly introduced into the large-diameter fiber bundle. Further, in order to improve the impregnating property of the resin, the resin viscosity is set to be in the range of 10 to 50 cp at room temperature, and as the fiber constituting the fiber bundle, for example, 1
There is also a method of using a relatively thick fiber of 00 to 1500 d. The fiber bundle may be hollow in terms of strength and cost. When it is hollow, by using a hollow pipe and forming a fiber bundle layer around it to prevent the hollow part from being crushed when it is placed in a mold and cured by heating, hollow fibers are formed. Preference is given to using the method of forming bundles. In FIG. 3, a hollow pipe 3 made of polyvinyl chloride is used as a hollow pipe, and a rod body 1 made of a resin-impregnated fiber bundle layer is formed around the hollow pipe 3, and a deformed portion 2 is formed on the outside thereof. The cross section of a large diameter FRP rod is shown.

The resin-impregnated fiber bundle obtained as described above is put in a rod-shaped mold having an irregular shape and cured by heating. The shape of the rod-shaped cross section may be circular, oval, oval, square, rectangular, hexagonal, trapezoidal, L-shaped, H-shaped, T-shaped, Y-shaped, etc. Any shape will do. The shape of the irregular shape (meaning a convex portion) is required to have a large convexity, good integration with the rod body, and good adhesiveness with concrete.
As a convex portion that satisfies these requirements, the convex portion height is 1 to
10 mm, a protrusion width of 2 to 20 mm, and a direction intersecting the length direction of the rod, preferably 45 with respect to the length direction of the rod.
It is preferable that the convex portions extending in a direction intersecting at an angle of at least 5 degrees are formed with an interval of 5 to 50 mm between the adjacent convex portions, and in particular, the convex portions are bamboo nodes as shown in FIGS. 1 and 2. Shape or spiral shape is preferable, and the convex shape has a convex height (height of irregular shape shown in FIG. 2) of 3 to 8
mm, the width of the convex portion (width at the bottom portion, width of the deformed portion shown in FIG. 2) is 4
~ 8 mm, spacing between adjacent protrusions (pitch shown in FIG. 2)
Is preferably 10 to 30 mm. In FIGS. 1 and 2, 1 indicates a rod body and 2 indicates a deformed portion.

When the resin-impregnated fiber bundle is put into the mold to cure the resin, the resin amount which is impregnated with the resin forming the odd-shaped portion is insufficient and a sufficiently-shaped irregular shape is formed. However, in such a case, it is preferable that the same resin as the resin is put in the mold before putting the resin-impregnated fiber bundle in the mold. Of course, in this case as well, it is preferable that the resin volume ratio of the rod after curing is within the range of the resin volume ratio. The resin-impregnated fiber bundle placed in the mold is pressed into a deformed rod shape and heated to cure the resin in that shape. The heating temperature may be a temperature at which the resin undergoes a curing reaction, for example, 60 to 180 ° C.
Is used. After the curing reaction is completed or almost completed, it is taken out from the mold. Inorganic particles such as sand may be attached to the surface of the rod in order to further improve the adhesiveness and fixing property of the obtained rod and concrete.

In the present invention, the integral feature of the deformed portion and the rod body is that the fiber bundle-impregnated resin and the resin of the deformed portion have the same composition, and curing is performed at the same time. When the main body and the odd-shaped portion are made of different resins, or when they are cured separately, the odd-shaped portion does not have a chemical bond, so the odd-shaped portion is separated from the rod main body. It is easily peeled off, resulting in poor fixability in concrete.

4 and 5 show a sectional view and a side view of a conventional large diameter FRP rod. As is clear from this figure, the conventional large-diameter FRP rod is obtained by bundling a plurality of small-diameter rods (7 in FIGS. 4 and 5) in which thin resin-impregnated fiber bundles are obliquely wound around the rod. This is the case where a diameter FRP rod is used. In the case of such a rod, peeling is likely to occur between the small diameter rods, and further, the obliquely wound fiber bundle is likely to be peeled from the surface of the small diameter rods, and thus the fixing property in concrete is poor.

The present invention will be described below with reference to examples. Examples 1-8, Comparative Examples 1-2 As Example 1, high-strength polyvinyl alcohol fiber of 70,000 d (Kuraray Co., Ltd. product number 7901, cutting strength 17.5 g /
dr, breaking elongation 4.9%, tensile modulus 350g / dr
Tow (single fiber denier 1.8 dr) consisting of epoxy resin (Epicote 828 manufactured by Yuka Shell Epoxy Co., Ltd.
A mixture of 00 parts by weight and 30 parts by weight of a curing agent LX-IN) is impregnated, and the solution is converged with the solution of Saku through a solution nozzle.
The fiber bundle was 10,000 d. This is the minimum diameter of the form 21mmφ
It was placed in the modified mold of No. 2 and heat-cured at 100 ° C. in a heating furnace to produce a large-diameter FRP deformed rod made of organic synthetic fiber having a deformed portion shown in Table 1. The volume ratio of resin in the rod is 45%
Met.

As Example 2, an outer diameter of 1 is provided at the center of the fiber bundle.
Large-diameter FRP variant made of organic synthetic fiber, which was heat-cured in a heating furnace in the same manner as in Example 1 except that a 0 mmφ PVC hollow pipe was inserted and the mold was placed in a profiled mold with a minimum diameter of 23.5 mmφ. A rod was made. The shape is shown in FIGS. 1 and 2. The dimensions of the irregular shape are shown in Table 1. The volume ratio of the resin in the rod was 45%. Examples 3 to 8 below
In the same operation as in Example 1, only different shapes are different as shown in Table 1. The volume ratio of the resin in the obtained rod is in the range of 42 to 48%.

As Comparative Example 1, 1800 denier / 10
High-strength polyvinyl alcohol fiber consisting of 00 filaments (Kuraray Co., Ltd. product number 7901, cutting strength 17.5 g /
dr, cutting elongation 4.9%, tensile modulus 350g / d
r) Assortment of 128 multi yarns (2.3400 million)
d) A fiber bundle, which is impregnated with an epoxy resin (a mixture of 100 parts by weight of Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd. and 30 parts by weight of a curing agent LX-IN), and is passed through a molding nozzle to have an inner diameter of a single wire of 6 mm. Was pultruded and 3 multi-yarns (18000d /
1000 f × 3) is twisted at 30 times / m, and two fiber bundles impregnated with the same resin as above are alternately wound on the surface of the rod at a pitch of 1 cm, and heat-cured in a heating furnace. The shape of the single wire shown in FIG. 4 was obtained. Twill winding yarn 5 is shown in FIG.
A single wire 4 wrapped around is shown. The twilled yarn 5 has a predetermined thickness and increases frictional resistance. Cut the required number of single wires to the required length, apply the above-prepared epoxy resin to the single wires, evenly arrange the six wires around the single wire core material, bundle them with a string, and leave them in the air overnight. Then, a large diameter rod made of organic synthetic fiber was obtained. The volume ratio of the resin in this large diameter rod was 42%. Its shape is shown in FIGS.

As Comparative Example 2, a large-diameter rod having no irregular shape was obtained by the same method as in Example 1, except that the rod was placed in a mold having a 21 mm diameter without irregular shape.

Table 1 and Table 2 show the shape of the deformed portion of the large-diameter rod obtained as described above, the strength, the Young's modulus, the adhesive strength with concrete, and the breaking condition of the deformed portion when the rod embedded in the concrete is pulled out. Shown in. In Table 2, the adhesiveness to concrete and the state of fracture of the deformed portion are shown as ready-mixed concrete (JIS
A 5308-1978) Standard product, ordinary concrete,
Slump 10 with air volume 4%, maximum size of coarse aggregate 20mm
cm, nominal strength 150 kg / cm ² , 210 kg / c
An embedded cured product was prepared by using m ² and 300 kg / cm ² and setting the rod embedding depth to 10 cm. Then, the rod was pulled out from the cured product, the strength was measured, and the adhesive force and the degree of peeling between the deformed portion and the rod body after the pulling were observed. The apparatus used for measuring the rod pull-out strength is shown in FIG. Regarding the state of destruction of the deformed portion, x is the case where the embedded portion of the deformed portion is substantially all destroyed, Δ is the case where more than half is destroyed, ○ is the case where it is partially destroyed, and there is virtually no destruction. The case is shown as ⊚.

[0018]

[Table 1]

[0019]

[Table 2]

In the examples, even if the concrete strength increases, the adhesive strength is improved by the anchor effect due to the irregular shape, whereas in the comparative examples, the irregular portion is destroyed or when there is no irregular shape, the concrete strength is improved. The adhesive strength with does not improve.

[0021]

According to the present invention, it is possible to obtain a large-diameter rod in which the deformed portion is less destroyed and the adhesive strength is very large when the concrete is embedded and then pulled out. As a result, it was found that the large diameter rod of the present invention had the following excellent properties. Terminal fixation when using the ground anchor is small and efficient. Due to the high adhesive strength, the earth effect is increased. If it is used to reinforce concrete, it is possible to produce a tough member without crack expansion. Has no rust, is lightweight and has excellent handleability.

[Brief description of drawings]

FIG. 1 is a sectional view of a large-diameter deformed rod of the present invention.

FIG. 2 is a side view of the large-diameter deformed rod of the present invention.

FIG. 3 is a sectional view of a large-diameter hollow variant rod of the present invention.

FIG. 4 is a cross-sectional view of a large diameter rod obtained by bundling the conventional obliquely wound small diameter rods.

5 is a side view of the large-diameter rod shown in FIG.

FIG. 6 is a view of an apparatus for measuring rod pullout strength.

[Explanation of symbols]

1. Rod body, 2. Deformed portion, 3. Hollow pipe,
4. Obliquely wound fiber bundle, 5. Single line, 7. Hydraulic pump,
8. Hydraulic gauge, 9. Fixing jig, 10. Washer, 1
1. Center pole jack, 12. concrete,
13. rod

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadayuki Yamamoto 1-2-1 Kaigan-dori, Okayama-shi Kuraray Co., Ltd.

Claims (2)

[Claims] 1. A rod in which a resin is impregnated and cured in a fiber bundle in which organic synthetic fibers are aligned in one direction, and the rod has an average outer diameter of 18 mm or more, and the outer circumference of the rod is A deformed rod made of a fiber-reinforced resin, comprising a convex portion made of the resin and extending in a direction intersecting the length direction of the rod. 2. A fiber reinforced resin rod is manufactured by placing a fiber bundle in which organic synthetic fibers are aligned in a thickness of 800,000 denier or more and impregnated with a curable uncured resin into a mold to be molded and cured. In the method described above, the mold is a mold having a groove having an average diameter of 18 mm or more in which the fiber bundle is inserted, and a concave portion extending on a surface of the groove in a direction intersecting a longitudinal direction of the groove. Manufacturing method of resin deformed rod.