JPH0718786A - Concrete reinforcing material and its production - Google Patents

Abstract

PURPOSE:To increase productivity, by applying molten thermoplastic polyamide resin on the external side of a rod after. serial fibers have been immersed in an adhesive and molded and then the fiber rod with half-cured adhesive has been molded flat. CONSTITUTION:A plurality of fiber filaments 1 of glass filaments or the like are parallelly set and immersed in a matrix adhesive liquid constituted of a mixture of vinyl ester and epoxy resin by means of an adhesive roll 2. Next, the filaments 1 are forced to pass through a die in order to form a specified shape. Then the filaments are heated in a first heating tank 4 to form a half- cured rod. And the upper and lower and also the right and left sides of the rod are pressed by pressing trowels 5, 6 to make flat shapes at every 10-50cm interval. After that, the rod is completely cured in a second heating tank 7. Moreover, the rod is forced to pass through rolls 8, 9 and coated with thermoplastic polyamide resin synthesized from dimerization fatty acid with 95% or higher purity and diamine. And after the treatment, it is cooled and drawn by rolls 10, 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fiber reinforced resin (hereinafter referred to as FR
P) and a method for manufacturing the same.

[0002]

2. Description of the Related Art When a reinforced concrete structure, a concrete panel or the like is constructed, reinforcing bars are longitudinally and laterally arranged as reinforcing materials, and the intersections thereof are bound by wire or fixed by welding or the like. However, when constructing a large-scale building or a concrete panel, the number of reinforcing bars used is large, and it takes a lot of time and labor to bind and weld the intersections one by one on site. Recently, FRP rods, which are lighter in weight and stronger in corrosion resistance than reinforcing bars, have been used as a reinforcing material for concrete, but in this case as well, they must be bound with wire or the like. Further, it is very bulky to carry the reinforcing material into the factory after assembling it in the factory, which makes transportation difficult.

Therefore, Japanese Laid-Open Patent Publication No. 4-76147 discloses a shaft reinforcement made of glass fiber impregnated with an ultraviolet curable resin (completely cured by irradiation of ultraviolet rays) and a shear reinforcement bar partially cured by partial irradiation of ultraviolet rays. Assemble it, fold it and reduce the bulk and bring it to the site,
Therefore, a method of assembling it at a predetermined position and completely curing the uncured portion by irradiating ultraviolet rays is disclosed. However, even in this case, if it becomes a reinforcing material for a large structure, even if it is folded, it is still quite bulky and it is difficult to transport, so its size is limited. There are some areas that are not enough to support cohesion, and some require some rework after assembly on site.

Further, in Japanese Patent Laid-Open No. 312659/1992, a plurality of linear rods are pulled in parallel while a FRP concrete reinforcing rod is manufactured by pull-through while the periphery thereof is spirally wound with a binding yarn impregnated with an adhesive. A method of manufacturing a reinforcing material and a truss by winding and hardening is disclosed. Even when such a reinforcing material or truss is assembled on site in a predetermined structure, it is necessary to bind each member and girder material with a wire or to bond them with an adhesive using a joint jig.

[0005]

[Problem to be Solved] When arranging a concrete reinforcing material made of reinforcing bars or FRP rods on site as described above, a method of exhibiting the same level of binding strength as conventional ones and connecting the intersections by a simple operation or equipment. Is desired. INDUSTRIAL APPLICABILITY The present invention provides a reinforcing material which can be manufactured in a process capable of improving productivity and mass production in the production of a concrete reinforcing rod by FRP, and can connect the intersections thereof by a simple operation when arranging on-site reinforcement. Is.

[0006]

In order to achieve the above object, the present invention is similar to the conventional method for producing a concrete reinforcing rod by FRP, in which a plurality of continuous fibers are merged in parallel to form an adhesive agent. After being impregnated with it and passing through a die to a predetermined shape, it is semi-cured by heating, and is a flat plate at intervals of 10 to 50 cm from the upper and lower sides and the left and right sides of the plane perpendicular to the traveling direction with respect to the rod traveling in that state. FRP characterized by alternately pressing with a pressing iron to mold the rod so that its cross section is flat, heating it to completely cure the rod, and then applying a molten special polyamide resin
The present invention provides a concrete reinforcing material and a manufacturing method thereof.

The continuous fibers used in the present invention are monofilaments or multifilaments such as glass fibers, carbon fibers and aramid fibers. The epoxy resin used for the FRP matrix in the present invention is bisphenol A.
(Or F) glycidyl ether, alicyclic epoxy resin, etc., Epicoat manufactured by Yuka Shell Epoxy Co., Ltd., Araldite manufactured by Ciba-Geigy Co., Ltd., D.E.R. manufactured by Dow Chemical Japan Co., Ltd. It is marketed under the trade name of Epotote manufactured by Tohto Kasei Co., Ltd. These epoxy resins are cured with a curing agent such as dicyandiamide, hydrazine, polyamines, acid anhydrides.

The vinyl ester resin used in the FRP matrix in the present invention was synthesized by reacting an epoxy resin with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid or maleic acid. ) Manufactured by Dainippon Ink and Dick Light manufactured by Dainippon Ink Co., Ltd. These vinyl ester resins are
Curing proceeds with peroxides such as cumene hydroperoxide, methyl ethyl ketone peroxide, and tert-butyl peroxide.

The special thermoplastic polyamide resin used in the present invention is a thermoplastic polyamide resin synthesized from high-purity dimerized fatty acid and diamine, which is produced by polymerizing unsaturated fatty acid such as oleic acid and linoleic acid. It is synthesized by reacting a dimerized fatty acid having a purity of 95% or more obtained by distilling a polymerized fatty acid with an aliphatic, aromatic or heterocyclic diamine. Since this polyamide resin has a relatively low melt viscosity and adheres well to metal, glass and plastic, it is widely used as a hot melt adhesive. This polyamide resin is commercially available under the trade name of Macromelt 6200, 6900 manufactured by Henkel Hakusui Co., Ltd.

When the FRP rod is prepared, long fibers such as glass fiber, carbon fiber, aramid fiber (polyparaphenylene phthalamide fiber, aromatic polyether amide) are arranged in one direction and the above-mentioned epoxy resin or epoxy is used. Impregnate a mixed adhesive of resin and vinyl ester resin,
In this case, the volume content of fibers in the rod is preferably 30 to 70% by volume. Moreover, the cross section of the rod drawn through the die by pull-through is circular, square, regular hexagonal,
Although it may be formed into various shapes such as a regular octagon, it is preferable that the fibers are uniformly contained in the matrix so as to withstand loads from multiple directions as much as possible.

When pressing the drawn rod in a semi-cured state with a flat plate pressing iron, as shown in FIGS. 1 (A) and 1 (B), a vertical surface (5 ) And the left and right (6) to install a flat plate pressing iron that presses the rod. The positions of the flat (5) and the horizontal (6) compression trowels are related to the speed at which the rod advances, but compression from the top and bottom and compression from the left and right are performed alternately on the rod, and the flatness due to each compression The interval between parts is 10
Adjust so that it is about 50 cm. A flat surface is formed on both sides of the rod vertically and horizontally with respect to the axial center of the rod by pressing in two directions, up and down and left and right. When arranging the rod, not only the planar structure but also the three-dimensional assembly, the intersection of the rods is formed. It is possible to take a large adhesion area. The larger the area of the plane formed by compression, the larger the adhesion area, but the cross section of the rod becomes extremely flat and the load becomes uneven, so the major axis of the section (a in FIG. 2) and the minor axis (FIG. 2). It is suitable that the ratio of b) is about 1.3 / 1 to 2/1. (See Figure 2)

[0012]

[Operation] As described above, the reinforcing material of the present invention can be relatively easily manufactured into a long product or a large or small diameter product by adding a few processing steps to the normal manufacturing process using FRP, and thus mass production is possible. It is possible and can be used in any combination depending on the application. That is, when assembling as a reinforcing material for a three-dimensional concrete structure, the rods are arranged so that the flat portions of the rods overlap at the intersections, and the joints are slightly heated with a hot air gun etc. The melted thermoplastic polyamide resin (2
(0 to 250 ° C) If you press it by hand, you can bond it in a short time, and you can assemble it with simpler operations and equipment than binding and welding with conventional wires.

Further, the flat surface formed on the surface of the reinforcing material at intervals of 10 to 50 cm increases the bonding area at the intersection,
When embedded in concrete, the anchor effect of the rod is improved and there is a pull-out prevention effect. Further, since the thermoplastic polyamide resin applied to the surface has strong corrosion resistance against acids, alkalis, salt water, etc., deterioration due to corrosion is prevented.

[0014]

1 and 2 are explanatory views showing a specific example of a method for manufacturing a reinforcing material of the present invention, FIG. 1 (A) is a side view, and FIG.
(B) shows a plan view. 2 (A) is a side view of the rod (round bar), (A ′) is a cross-sectional view at a, and FIG. 2 (B).
Shows a plan view of the rod, and (B ') shows a sectional view at a' thereof. FIG. 3 shows a diagram for measuring the adhesive strength of two rods that are orthogonally bonded.

The reinforcing rod is prepared by firstly arranging a plurality of continuous fibers (multifilament or monofilament) in parallel and impregnating them with a matrix adhesive solution (epoxy resin or a mixture of vinyl ester and epoxy resin) with a roll (2) to form a die ( It is made into a desired shape through 3) and heated in the first heating tank (4) until it becomes semi-cured. A semi-hardened rod that advances with a compression iron with a pair of flat metal surfaces installed in the same tank is pressed from above and below (5) and left and right (6) (up and down and left and right of a plane perpendicular to the moving direction) to the rod. Add a flat shape. Adjust the moving speed of the rod and the position of the compression iron,
Form a flat cross section alternately in the longitudinal and lateral directions at intervals of 10 to 50 cm in the axial direction of the molded rod (see Fig. 2). The pressing force is related to the hardness of the semi-cured resin, but the ratio of the major axis (a) to the minor axis (b) of the flat cross section is preferably 1.3 / 1 to 2.0 / 1. If the a / b ratio becomes larger than this, the load becomes non-uniform, which is not preferable.

The molded rod enters the second heating tank (7) and is further hardened by heating at a high temperature. The rod exiting the second heating tank passes between the rolls (8, 9) to apply the molten thermoplastic polyamide resin there. The coating amount is adjusted by the passage speed of the rod and the temperature and viscosity of the polyamide resin, and it is preferable that the outer side of the rod has a thickness of 0.2 to 1 mm. The rod cooled by the applied polyamide resin is taken by a roll (10, 11) and cut into an appropriate length.

The adhesive strength of the reinforcing rod thus manufactured was measured by the following method. The flat surfaces of the rods (c and d) were heated to 220 ° C. with a hot air gun, and the two rods were pressure-bonded so as to be orthogonal to each other while the applied polyamide resin was softened. After left at room temperature for 1 day, the jig (e) shown in FIG. 3 was hooked on the rod c to pull e and d, and the adhesive force was measured. Adhesive strength 80-130 kgf / cm ²

[0018]

As described above, the present invention has the advantages of the conventional F
By adding a slight improvement step to the method of manufacturing the concrete reinforcement rod by RP, it is possible to carry out continuous production in a relatively simple and large amount. The reinforcement rod produced in this way is used as a reinforcing bar when constructing large-scale concrete structures and panels, but when bonding the intersections, the rod surface is slightly heated by a hot air gun ( After the temperature is 200 to 220 ° C), it can be easily joined by crimping by hand, which is less troublesome than binding and welding using conventional wire. Further, as shown in FIG. 2, since it has an uneven shape, it has an anchoring effect after being embedded in concrete and has an effect of preventing pulling out. The rod made of this fiber reinforced resin is lightweight,
It has strength against stress in each direction such as tension, compression, shearing and bending, and has a large resistance to corrosion by acids, alkalis, salts and the like.

[0019]

[Brief description of drawings]

FIG. 1A is a side view of an apparatus for manufacturing a reinforcement rod of the present invention. (B) is a plan view of the apparatus.

FIG. 2A is a side view of the reinforcing rod of the present invention. (A ') is a cross-sectional view of the rod in (A) at a. (B) is a plan view of the reinforcing rod of the present invention. (B ') is a cross-sectional view at a'of the rod in (B).

FIG. 3 is a view showing an adhesive strength measurement between two rods which are orthogonally bonded.

[Explanation of symbols]

 1. Fiber filament beam 2. Adhesive (matrix) roll 2 '. Adhesive (matrix) tank 3. Die 4. First heating tank 5. Vertical pressing iron 6. Horizontal pressing iron 7. Second heating tank 8, 9. Polyamide resin coating roll 8 '. Polyamide resin melting tank 10,11. Take-up roll a, b'Long diameter of flat cross section b, a'Short diameter of flat cross section c, d Two rods bonded orthogonally e. Pulling Jig used for

Front page continued (72) Inventor Junichi Takahashi 2-5-8 Imabashi, Chuo-ku, Osaka-shi, Osaka Nissho Iwai Building Henkel Shiramizu Co., Ltd.

Claims (4)

[Claims] 1. A rod which is obtained by merging a plurality of continuous fibers and impregnating them with an epoxy resin or vinyl ester / epoxy resin mixed adhesive and forming them into a predetermined shape through a die, and then progressing in a semi-cured state by heating. After pressing the rod alternately with the pressing iron of the flat plate from the top and bottom and the left and right of the cross section at intervals of 10 to 50 cm and partially deforming so that the cross section becomes flat, the impregnated resin is completely cured by heating,
After that, a molten special thermoplastic polyamide resin is applied to the outside of the rod, which is a fiber-reinforced resin concrete reinforcing material. 2. A method for producing a concrete reinforcing material made of fiber reinforced resin, which comprises the following steps (a), (b), (c), (d) and (e). (A) A step of merging and aligning a plurality of continuous fibers and impregnating them with an epoxy resin or vinyl ester and an epoxy resin mixed adhesive. (B) A step of passing through a die to give a predetermined shape and heating to a semi-cured state. (C) For the rod that advances in the heating furnace in the semi-cured state, the rod is pressed by the pressing iron of the flat plate alternately at the intervals of 10 to 50 cm from the top and bottom and the left and right of the cross section so that the cross section becomes flat. Process to transform into. (D) A step of further heating to completely cure the rod. (E) A step of applying a molten thermoplastic special polyamide resin to the advancing rod. 3. A concrete reinforcing material made of fiber reinforced resin according to claim 1, which comprises applying a special thermoplastic polyamide resin synthesized from dimerized fatty acid having a high purity of 95% or more and diamine as an adhesive to the outside of the rod. 4. A fiber reinforced resin comprising applying a special thermoplastic polyamide resin synthesized from 95% or more of high-purity dimerized fatty acid and diamine as an adhesive to the outside of the rod in the step (e) of claim 2. Manufacturing method of concrete supplementary teaching materials.