WO1995033109A1

WO1995033109A1 - Fibre reinforced resin composite reinforcing material and method for producing the same

Info

Publication number: WO1995033109A1
Application number: PCT/JP1995/001029
Authority: WO
Inventors: Toshikazu Takeda; Masaki Shimada; Yoichi Kitagawa; Yoshikazu Izumihara; Masato Miyake; Masayuki Andoh; Toshiaki Seki; Shuuji Takiyama; Kohji Ogata
Original assignee: Nippon Steel Corporation
Priority date: 1994-05-27
Filing date: 1995-05-29
Publication date: 1995-12-07
Also published as: CA2191241A1

Abstract

A curved fibre reinforced resin composite reinforcing material is produced by forming a formed body by in turn winding a bundle of the thermosetting resin impregnated reinforcing fibres which is twisted to a predetermined extent around the surface of a core portion of a bundle of thermosetting resin impregnated reinforcing fibres and applying a thermosetting process to the formed body while subjected to a tension to produce a distortion amount of 500-3000 ν/m in an axial direction thereof, or by fixing the formed body formed by winding a bundle of thermosetting resin impregnated reinforcing fibres around the twisted core portion in a curved mold curved at a predetermined radius of curvature and subjecting the formed body to thermosetting processing, whereby a fibre reinforced resin composite material having a high strength is provided at low costs which is useful as a substitution material for an iron rod or PC steel wire.

Description

Description Fiber reinforced resin composite reinforced material and method for producing the same

The present invention relates to a fiber-reinforced resin composite reinforcing material used as a reinforcing bar when embedded in a concrete product such as a building or structure made of the concrete and used as a reinforcing bar. It relates to a manufacturing method. Background art

Hitherto, fiber-reinforced resin composite reinforcing bars have been proposed as substitutes for reinforcing bars or PC steel wires. This fiber reinforced resin composite reinforced material is formed by impregnating a high elasticity, high strength continuous fiber such as carbon fiber or aramide fiber with a thermosetting epoxy resin and curing it. It is known as a lightweight, high-strength, high-corrosion-resistant reinforcement. Such a fiber-reinforced resin composite rebar has many characteristics such as light weight, high strength and high corrosion resistance, and can be cut with a woodworking saw and has excellent cutting properties. Therefore, it is expected that its use as reinforcing bars embedded in various concrete products will be expanded in the future.

By the way, such a conventional fiber-reinforced resin composite bar has two major problems as described below.

That is, the first problem is that the fiber-reinforced resin composite reinforced material has a low surface adhesion and therefore has a poor transmission of tensile force due to its smooth surface.

The second problem is that it is difficult to increase productivity, and in view of the strength of the reinforcing fiber used, its guaranteed strength is only at a very low level, in fact less than half. Is not expressed That is it.

First, regarding the first problem, various methods have been proposed in the past to solve this problem. For example, the following five methods are known.

That is, the first method is to form a convex portion by winding a plurality of reinforcing woven bundles around a core portion, as proposed in Japanese Patent Application Laid-Open No. 61-274036, and to adhere to the concrete. How to ensure.

The second method is a method in which a granular material (Japanese Patent Application Laid-Open No. 4-363454) and a short-woven fiber (Japanese Patent Application Laid-Open No. 2-248559) are adhered to the surface.

The third method is to increase the adhesive force by directly providing a mechanical recess in the core as proposed in JP-A-63-206548 and JP-A-63-219746. .

As a fourth method, as disclosed in Japanese Patent Application Laid-Open No. 3-151444, a method in which a plurality of rods are curved and structurally locked, and a method proposed in Japanese Patent Application Publication No. Hei. In this method, the surface fibers of the core of the rod are made to undulate with a die having an uneven inner surface to form the unevenness.

Finally, as a fifth method, as proposed in Japanese Patent Application Laid-Open No. Hei 4-1363454, the fibers in the axial direction are braided to form irregularities on the surface to secure the adhesive force with the concrete. How to

However, in the third to fifth methods, the core fiber undulates or the core fiber is mechanically damaged, so that the adhesion to the concrete increases, but the core strength is increased. This is unsuitable from the viewpoint of producing a high-strength fiber-reinforced resin composite reinforcing bar. In addition, it is disadvantageous in terms of cost because it is necessary to increase the amount of fiber to satisfy the required strength.

The second method is to use small granular materials and short fibers that are not continuous. The resin is only adhered to the surface of the core with the adhesive force of the resin, and sufficient adhesive force with the concrete cannot be secured.

Furthermore, the first method can be said to be the most excellent in that it can be manufactured without reducing the fiber strength of the core portion. As described above, in any of these first to fifth methods, in any case, the adhesion to the concrete can be improved without impairing the high fiber strength of the core. It is difficult to increase it to a level comparable to that of steel, and up to now, there is no known fiber-reinforced resin composite reinforcing material with a level of strength that exceeds or exceeds that of rebar.

In addition, the present inventors have studied the second problem, and as a result, have found that a drawing method proposed as a typical method for producing a fiber-reinforced resin composite reinforcing bar (for example, Japanese Patent Application Laid-Open No. 61-274036). In Japanese Patent Application Laid-Open No. 2-248559, the drawing speed is determined by the conditions for performing the drawing. For this reason, the productivity is limited. At the same time, the required tension could not be applied to the reinforcing fiber bundle.

On the other hand, as the market for such fiber-reinforced resin composite materials has been expanded, there has been a demand for the development of not only straight bars but also bars having a predetermined radius of curvature depending on the application. For example, fiber-reinforced composites are currently attracting attention for their good machinability, and plans have been made to use the caisson method, one of the methods for excavating pits when excavating underground tunnels, as a substitute for reinforcing steel at the opening of the hole. However, this requires the use of curved muscle.

However, at present, only fiber-reinforced resin composite bars having a straight rod shape are known. The only option was to mechanically bend the straight bar. However, this fiber-reinforced resin composite material is a brittle material that does not undergo plastic deformation unlike metal, and the elongation of the reinforcing fibers is extremely small, at most about 1 to 2%. If mechanical bending is performed, the reinforcing fibers will be damaged, such as breakage of some fibers.If the bending radius is small, the original high strength of fiber-reinforced resin composite muscle will be lost. In addition, even if the bending radius is large, a stress is generated due to bending, and a reduction in the usable strength of the reinforcement is inevitable. In any case, the original high strength of the reinforcement is impaired. there were.

By the way, in general, if a resin-based composite material is to be bent after being cured, forced bending is inevitably performed, which causes the above-described problem. It is also conceivable to re-bent the reinforcing material to a temperature of 120 ° C or higher and soften the resin impregnated in the reinforcing fiber bundles to perform bending.However, this bending is difficult when working at high temperatures. In addition to this, the work becomes extremely time-consuming, and even in this method, local buckling and strength deterioration inevitably occur in the reinforcing fiber, and the original function of the fiber-reinforced resin composite reinforcement is exhibited. It cannot be done.

Accordingly, an object of the present invention is to provide a fiber-reinforced resin composite reinforced material capable of exhibiting an adhesion to a concrete that is equal to or greater than that of a metal reinforcing bar without deterioration in core strength. Is to do.

Another object of the present invention is to make it possible to bring out the strength of the reinforcing fiber itself, thereby reducing the amount of reinforcing fiber and thereby reducing the product cost. Another object of the present invention is to provide a fiber-reinforced composite reinforcing material having a high guaranteed strength.

Further, another object of the present invention is to provide excellent concrete adhesion. Another object of the present invention is to provide a method for producing a fiber reinforced composite reinforced material capable of producing a fiber reinforced resin composite reinforced material having a high guaranteed strength with good productivity and at a low cost.

Still another object of the present invention is to provide a fiber-reinforced resin composite reinforcing material having a high dimensional accuracy by bending at a predetermined radius of curvature and having high strength.

Another object of the present invention is to provide a method for easily producing a fiber-reinforced resin composite rebar having high dimensional accuracy and high strength, which is curved at a predetermined radius of curvature, without deteriorating its strength. Is to provide. Disclosure of the invention

The present inventors have conducted intensive research to solve the above problems, and as a result, regarding the first problem,

In a fiber-reinforced resin composite reinforced material having a core portion and a convex portion on the surface thereof, the reinforcing fiber bundle constituting the convex portion on the surface is twisted to reduce the strength of the core without deteriorating the strength of the core portion. It has been found that the adhesion can be significantly improved.

Regarding the second problem, the core part and the convex part are sequentially formed, and the obtained molded body is heat-cured while applying a tensile force in the axial direction (the direction of the reinforcing fiber bundle), thereby forming a peripheral part. Without giving tensile stress to the resin (resin is easily broken by tensile stress, so that compressive stress is applied), by aligning the fiber direction and applying tensile stress, the high strength of the reinforcing fiber itself and It has been found that a high elasticity can be obtained, and thus, a fiber-reinforced composite reinforcing material having high production efficiency and high guaranteed strength can be manufactured.

In addition, in order to give the fiber-reinforced resin composite reinforcing material a gluttony without deterioration in strength, a twist is added to the core and a molding consisting of the core and the surface convex It has been found that it is effective to apply a thermosetting treatment while applying a certain tensile stress to the core while the body is bent. When a tensile stress is applied to the core, each unit fiber constituting the core is subjected to an equal tensile stress. Therefore, even if the core is twisted and curved, the local seat of the molded body is formed. Flexing and reduction in strength could be completely avoided.

Hereinafter, the present invention will be further described.

The present invention relates to a core and a crimped portion made of a thermosetting composition comprising a thermosetting resin and a reinforcing fiber bundle (the crimped portion forms a convex portion on the surface of the core portion).

) Is a fiber-reinforced resin composite rebar having a strain of 500-3000Ζπι due to tensile force.

In order to manufacture this composite rebar, for example, a filament winding device is used, jigs having a plurality of pins are attached to both end chuck portions of the device, and heat is applied between the pins of the pair of jigs. A reinforcing fiber impregnated with a thermosetting resin is impregnated with a fiber bundle for impregnating the thermosetting resin on the surface of the core by wrapping the reinforcing fiber bundle impregnated with the curable resin and forming the core by the filament winding method. The convex is formed by tightening, and the obtained molded body is subjected to a thermosetting treatment while applying a tensile force in the axial direction. In addition, a predetermined twist is applied to the reinforcing woven bundle that forms the convex portion.

With the above configuration, the composite reinforcing material of the present invention has a high tensile strength that exhibits the original strength of the reinforcing fiber, and significantly improves the adhesion to the concrete while preventing fiber damage. Can o

Further, the present invention provides a core formed from a reinforcing woven fiber bundle impregnated with a thermosetting resin and having a predetermined twist, and a reinforcing fiber bundle impregnated with the thermosetting resin wound around the core. A curved fiber-reinforced resin composite reinforced material having a convex portion formed as a whole and having a predetermined radius of curvature.

In order to manufacture this composite rebar, the core is first formed and then After the core is twisted, at least one reinforced fiber bundle impregnated with a thermosetting resin is used to form a convex portion, and the obtained core member with a convex portion, that is, the molded body is bent at a predetermined radius of curvature. The thermosetting resin impregnated in the reinforcing fiber bundle is heat-set while applying a certain tensile stress to the core while fixing the core in a curved shape.

Alternatively, as another method, a convex portion is formed on the molded core portion by using a reinforcing woven fiber bundle impregnated with at least one thermosetting resin, and twisting is performed in the same direction as the formed convex portion. The core member with a convex portion, that is, the molded body is fixed in a curved mold having a predetermined radius of curvature, and a thermosetting resin is impregnated into the reinforcing fiber bundle while applying a constant tensile stress to the thermosetting resin. Apply. The curved fiber-reinforced resin composite bar thus manufactured is extremely preferable as a reinforcing bar used for excavating a pit for sewerage works, subway works and the like. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partially sectional front view of a jig used in the filament winding method.

FIG. 2 is a conceptual explanatory diagram of the filament winding method. FIG. 3 is a partial perspective view of a metal fixed type.

FIG. 4 is a partial front view showing a fiber-reinforced resin composite reinforced material according to one embodiment of the present invention.

FIG. 5 is a partial front view showing the fiber-reinforced resin composite reinforcing bar of Comparative Example 1.

FIG. 6 is a partial cross-sectional front view showing the fiber-reinforced resin composite reinforced material of Comparative Example 3.

FIG. 7 is a partially sectional front view showing a test method of a tensile test. No. 81¾ is the average bond stress and slip amount obtained from the tensile test. FIG. 6 is a graph showing the relationship between

FIG. 9 is a partial cross-sectional perspective view showing a pad-like specimen used in a tensile test in the present invention example and the comparative example.

FIG. 10 is a partial perspective view showing a state in which a curved fiber reinforced resin composite reinforced material according to another embodiment of the present invention is formed.

FIG. 11 is a partial perspective view showing a curved fiber reinforced resin composite reinforced material according to another embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

First, the linear fiber-reinforced resin composite reinforcing material of the present invention will be described. In the present invention, the reinforcing fibers for forming the reinforcing fiber bundle are conventionally known as long as the fibers are continuous from the starting end to the end of the composite reinforcing bar to be manufactured. Can be used as appropriate, and examples thereof include various carbon fibers such as PAN (polyacrylonitrile), pitch, and hybrid, and aramide fibers and glass fibers. Also, as the thermosetting resin (reinforced resin) to be impregnated into the reinforcing fiber bundle, conventionally known ones can be appropriately used, and examples thereof include an epoxy resin, a phenol resin, and a polyamide resin. be able to. These reinforcing fibers and thermosetting resins can be appropriately selected depending on the use of the composite reinforcing material to be produced, but from the viewpoints of heat resistance, corrosion resistance, etc., the reinforcing fibers are preferably made of carbon. It is a fiber, and the thermosetting resin is preferably an epoxy resin.

In the present invention, the molding of the core portion may be performed, for example, from the viewpoint of simply improving the adhesiveness of the concrete, by, for example, using a carbon woven yarn impregnated with a thermosetting resin as a core and surrounding the core with a thermosetting resin impregnated. A hand lay-up method in which a carbon fiber prepreg is formed by winding it It can be formed by assembling carbon fiber yarn impregnated with thermosetting resin and winding it around with a braider using a blader device, or by drawing, etc. Preferably, the following method is used.

That is, a jig having a plurality of pins is attached to both ends of a filament winding device (hereinafter abbreviated as “FW device J”), and thermosetting is performed between the pins of the pair of jigs. A reinforcing fiber bundle impregnated with a conductive resin is wrapped around the core, and a core is formed by a filament winding method (hereinafter abbreviated as “FW method J”). This is a method in which a convex portion is formed by winding a reinforcing fiber bundle impregnated with resin to form a convex portion, and the obtained molded product is thermally cured while applying a tensile force in the axial direction. This method is specifically described below. I do.

That is, first, as shown in FIG. 1, a grip portion 2 is provided on the base end side and a plurality of (2 to 10) pins 3 are provided on the distal end side. In FIG. 2, a pair of metal jigs 1 each having a fixing portion 4 composed of a male screw 5 and a nut 6 are prepared. Attach it to the chuck section 8 at both ends of the twisting device 7.

Next, a plurality of reinforcing fiber bundles 9 for reinforcement are continuously fed out and passed through a resin bath 10 of thermosetting resin, where the woven fiber bundle for reinforcement is impregnated with thermosetting resin. The woven fiber bundle impregnated with the thermosetting resin impregnated with the thermosetting resin is traversed by the traverser 11 until the diameter of the woven bundle reaches a required value between the plurality of pins 3 provided on the pair of jigs 1. A plurality of thermosetting resin impregnated reinforcing fiber bundles are arranged in the axial direction to form a core.

The core formed in this manner is included in the reinforcing fiber bundle. The soaked thermosetting resin must be in a completely uncured state until the next time a convex is formed on the surface and it is thermoset, but even if it is completely uncured, Further, it may be in a semi-cured state called B stage. Further, the fiber volume content of the core is preferably 40 to 0%, more preferably 50 to 60%. When the fiber volume content is lower than 40%, the resin is excessive and the resin is hardened at the time of curing. There is a risk that sagging will occur, and if it is greater than 70%, there is a risk that poor adhesion between the core and the protrusion may occur due to insufficient resin.

On the core formed in this way, at least one reinforcing fiber bundle impregnated with a thermosetting resin is wound around the surface to form a convex portion, and the core and the surface are formed on the core. The molded body has a convex portion. At this time, the impregnation of the reinforcing fiber bundle with the thermosetting resin and the winding around the core may be continuously performed using a FW device at the time of molding the core. It may be carried out by bringing in a reinforcing fiber bundle impregnated with a thermosetting resin in advance.

Here, the thermosetting resin impregnated in the reinforcing fiber bundle to form the convex portion and the fiber volume content thereof may be the same as in the case of the core portion.

Here, the reinforcing fiber bundle impregnated with a thermosetting resin to be wound around the surface of the core is preferably 10 to 10 m / m per reinforcing fiber bundle in order to improve the adhesion to the concrete. Twisting the core 50 times and winding it around the core should be done at an angle of 65 to 85 ° to the axial direction.

If the twist given to the reinforcing woven fiber bundle constituting the convex portion is less than 10 times per 1 m, the adhesion to the concrete is not significantly improved, and if it exceeds 50 times, fiber damage and damage may occur. A decrease in adhesion to the core occurs. In addition, if the angle at which the twisted reinforcing fiber bundle is wrapped is smaller than 65 ° with respect to the axial direction of the core, there is a problem that the adhesive strength of the concrete decreases. On the other hand, even if the angle is larger than 85 °, the problem of a decrease in concrete adhesion occurs.

When the fiber-reinforced bundle impregnated with a thermosetting resin is wound around the core in a coil shape to form a convex portion, the twisted fiber is folded back over the core to orientate in a cross ( Adhesion with concrete is maximized, but after the maximum, it suddenly pulls out of concrete, which is unsuitable for actual use. Is

0

In this way, the molded body in which the protrusions are formed by winding the fiber bundle for impregnating and reinforcing the thermosetting resin on the surface of the core portion is used in order to sufficiently exhibit the strength of the reinforcing fiber used. The molded body is thermoset while applying a tensile force in the axial direction (that is, a tensile force on the axial fibers constituting the core).

Here, as a method for applying a predetermined tensile force to the axial fibers of the molded body, basically any method may be used, but preferably, both ends of the molded body are fixed to a metal with a pair of jigs. It is fixed to both ends of the mold, and the whole is heated as it is with the metal fixed mold, and the thermosetting resin impregnated in the reinforcing woven fiber bundle is thermoset, and due to the thermal expansion of the metal fixed mold at this time, This is a method of applying a tensile force to a molded body. By adopting such a method, it is possible to more easily produce a high-strength fiber-reinforced resin composite reinforced material having a high guaranteed strength.

That is, the molded body 12 formed as described above and having the uncured core 13 and the uncured protrusion 14 is removed together with the pair of jigs 1 from the both-ends chuck 8 of the FW device 7. As shown in FIG. 3, a metal material having a thermal expansion coefficient at least larger than the thermal expansion coefficient of the reinforcing fiber bundle is utilized by using the male screw 5 and the nut 6 of the pair of jigs 1 located at both ends thereof. fixed on both ends of the fixed mold 15, 50 in this state at a temperature of about 1 10 to 200 DEG ^e C Heat treatment is performed for 120 minutes to thermally cure the thermosetting resin impregnated in the reinforcing woven fiber bundle of the molded body 12, thereby forming the reinforcing fiber bundle in the reinforcing fiber bundle as shown in FIG. Thus, a fiber-reinforced resin composite reinforced material 16 having a core portion 17 and a convex portion 18 in which the thermosetting resin impregnated into the resin is cured is obtained.

The tensile force applied at the time of this heat curing is preferably from 500 to 3,000 a / m, preferably from 800 to 2,000 μm in terms of strain. If the amount of strain due to the tensile force applied during this thermosetting is less than 500 ^ m, it is not possible to develop high strength enough to overcome the thermosetting resin existing around the reinforcing fibers, and the orientation of the reinforcing fibers The strength of the reinforcing fiber is reduced, and the original strength of the reinforcing fiber cannot be exhibited. As a result, if external stress is actually applied, excessive stress is applied to the resin, and the composite reinforcing material is broken. On the other hand, if it exceeds 3,000 mm Zm, the reinforcing fabric will be damaged, and the strength will be reduced.

Note that the tensile force exists as a residual stress even at room temperature, and therefore, the amount of strain due to the tensile force remains at room temperature.

Here, an example is shown in which a compact was set at a room temperature of 20 in an iron metal fixed mold 15 having an expansion coefficient of 1 × 10 ⁵ (1Z.C), and a thermosetting treatment was performed under the following conditions. Show. Male reinforcing fibers have a very low coefficient of thermal expansion as compared to iron, so 1 10. C, a tensile stress of about 800 / Zm by performing a heat hardening treatment for 60 minutes, and 220. By performing the heat hardening treatment for 60 minutes at C, a tensile stress of about 2,000 Zm could be developed. This range of tensile stress is particularly preferred.

The use of such fiber-reinforced resin composite rebar in a concrete block reduces the compressive stress of the resin in the reinforcing bars that support the tensile side of the block in the block. The resin part is prevented from breaking without being pulled, and the properties of the fiber bundle as a whole are maintained. Next, the curved fiber reinforced resin composite reinforced material will be described.

The composite reinforcing material uses the same reinforcing fibers and thermosetting resin (reinforced resin) as in the case of the linear composite reinforcing material. In addition, it is preferable to use a FW device in order to manufacture a molded body of the curved composite reinforcing bar. In this embodiment, after the molded body is manufactured, one of a pair of jigs 1 (see FIGS. 1 and 2) used in the above method is fixed, and the other is rotated to apply a predetermined twist to the core of the molded body. Add.

Here, the twist applied to the core should be 0.5 to 1 rotation per meter. If the core is not twisted, or if the twist is less than 0.5 rotations per lm, it may cause local buckling of the compact when the compact is maintained in a curved shape. If the rotation exceeds 1 rotation per lm, the torsion may return after curing due to the rigidity of the reinforcing fiber.

Therefore, by applying such a twist, local buckling of the molded body can be prevented.

In addition to the above method, after forming the core, the core is twisted, and at least one reinforcing fiber bundle impregnated with a thermosetting resin is wound around the surface thereof. Protrusions may be formed. The impregnation of the thermosetting resin into the reinforcing woven fiber bundle and the winding around the core may be performed continuously using a FW device during molding of the core. Alternatively, the method may be carried out by bringing in a reinforcing fiber bundle impregnated with a thermosetting resin in advance.

The thermosetting resin impregnated in the reinforcing fiber bundle of the molded body manufactured in this way needs to be in a state where it is not completely cured until it is thermally cured in the next step, but it is not completely cured. It may be in a cured state or in a semi-cured state called a B stage. The fiber volume content of the core is preferably 40 to 0%, more preferably 50 to 60%. If the fiber volume content is lower than 40%, the resin is excessive. However, there is a problem that resin dripping occurs at the time of curing, and if it exceeds 70%, there is a problem that insufficient resin causes poor adhesion between the core portion and the convex portion.

Next, the molded body is removed together with the pair of jigs 1 from both end chuck portions 8 of the FW device 7 shown in FIG. 1, and then, as shown in FIG. Using a male screw 5 and a nut 6 of a fixing portion 4 provided on the jig, a curved portion having a receiving portion 13 having a predetermined radius of curvature and jig stoppers 14 provided at both ends thereof. Mounted on mold 12. In this state, the molded body is heated at about 110 to 200'C for 50 to 120 minutes while applying a tensile force using a mechanical method or the thermal expansion of a metal mold, and the core is formed. Product in which the thermosetting resin impregnated in the reinforcing woven fiber bundles constituting the convex portions and the convex portions is thermoset, and the convex portions 17 are wrapped around the core 16 as shown in Fig. 1. The curved male fiber reinforced resin composite reinforcing material 15 is manufactured. The tensile force in this case is also applied to the formed body so as to impart a strain of 500 to 3000 Zm to the composite reinforcing bar.

The radius of curvature of the curved fiber reinforced resin composite reinforcing material is not particularly limited.For example, a composite reinforcing material used for excavating a pit for sewerage works is about 6 to 10 m, and electric underground wiring is used. About 2 to 4 m of composite rebar used for excavating shafts for duct work, and about 15 to 20 m for composite rebars used for excavating shafts for subway construction. .

As described above, according to the method of the present invention, in the linear fiber reinforced resin composite reinforced material, a predetermined twist is applied to the reinforcing fiber bundle that forms the convex portion on the surface of the core portion, thereby increasing the peak height of the convex portion. As a result, adhesion to concrete can be significantly improved without deteriorating the strength of the core.

In addition, thermosetting is performed while applying tensile force to the axial textile of the obtained molded body. To produce a high-strength fiber-reinforced resin composite reinforcing bar with high guaranteed strength, which can produce composite reinforcing bars at high speed, and can evenly eliminate multiple slacks by reinforcing multiple woven fibers. Can be.

In addition, in the curved fiber reinforced resin composite reinforcing material, the reinforcing fibers constituting the obtained curved composite reinforcing material do not undergo local buckling or deterioration in strength, and the manufactured reinforcing material is reheated. This eliminates the need for time-consuming operations such as bending and bending, thus greatly facilitating the manufacturing process of the curved fiber-reinforced resin composite rebar. Example

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

0

Example 1

Epoxy resin is impregnated into a carbon fiber having an elastic modulus of 3.4 xl 0 ⁵ MPa, and a core having a diameter of 200 in which the carbon fiber is axially oriented at a volume ratio of 55% is used. Twenty twisted winding fibers impregnated with epoxy resin are twisted 20 times per meter into 8 bundles of carbon fiber bundles, and coiled at an angle of 80 ° with respect to the axial direction of the core. The molded body is formed by winding, and the thermosetting resin impregnated in the carbon fiber bundle forming the core portion and the convex portion of the molded body is cured, and as shown in FIG. 4, the core portion and the surface thereof are formed. A fiber-reinforced resin composite bar of a product in which a thermosetting resin impregnated in a carbon woven fiber bundle is cured and has a convex portion 18 formed of a winding carbon fiber bundle twisted into Material 16 was produced.

Comparative Example 1

As shown in Fig. 5, the surface of the core 17 is twisted in the axial direction with a bundle of carbon fibers for tightening, which is turned into a coil form at an angle of 80 °, Except for forming the convex part 18 oriented in the cloth, A fiber-reinforced resin composite reinforcing material 16 was produced in the same manner as in Example 1, and this was used as Comparative Example 1.

Comparative Example 2

Next, except that the resin was directly impregnated with a twist of eight carbon fibers without twisting, and this was wound into a coil at an angle of 80 ° to the axial direction of the core. A fiber reinforced resin composite reinforcing bar (not shown) was produced in the same manner as in Example 1 above, and this was designated as Comparative Example 2.

Comparative Example 3

As shown in FIG. 6, a surface layer 19 (composed of fiber and impregnated resin) having a wavy height of about 3 mm is formed on the surface of the core 17 without performing the tightening. A fiber-reinforced resin composite reinforced material 16 was produced in the same manner as in Example 1 except that the projections were formed on the surface of the core 17.

Comparative Example 4

Approximately 200 ready-made iron bars were used as Comparative Example 4.

The fiber-reinforced resin composite reinforcing bars 16 of Example 1 and Comparative Examples 1 to 4 prepared in this manner were subjected to the standard of the Japan Society of Civil Engineers as shown in FIG. Application to Concrete ”(pages 26 to 27) was tested for adhesion of concrete. In Fig. 7, reference numeral 20 is a displacement meter, and reference numeral 21 is a concrete.

Ό

The results are shown in FIG. The amount of slip on the horizontal axis in this figure represents the numerical value of the displacement meter 20, and indicates the amount of pullout of the composite bar from the concrete.

As is clear from FIG. 8, the fiber-reinforced resin composite reinforced material of Example 1 exhibited an adhesive force equal to or higher than that of the iron reinforced material of Comparative Example 4. In addition, the fiber-reinforced resin composite reinforced material of Comparative Example 1 had a high initial strength, but then suddenly showed a decrease in strength. In Comparative Example 2 where no twist was applied, the adhesive strength was Less than half.

Example 2

Epoxy resin is impregnated into a carbon fiber having an elastic modulus of 3.4 xl 0 ⁵ MPa, and a core having a diameter of 200 in which the carbon fiber is axially oriented at a volume ratio of 55% is used. Twenty twisted weaves, impregnated with epoxy resin, are twisted 20 times per meter into eight bundles of Z bundles of carbon fibers, and 80 with respect to the axial direction of the core. The formed body was wound in a coil shape at an angle of, and formed using a filament winding apparatus.

Next, the obtained molded body together with the jigs attached to both ends thereof were removed from the filament winding device, and as shown in FIG. and fixed to the fixed mold, the epoxy resin impregnated into the carbon fiber bundle that form a molded body is heat cured in a heating treatment of 0.99 ^e C, 60 min, manufactured of woven fiber-reinforced resin composite muscle material example 2 did. At this time, the tensile force acting on the fiber-reinforced composite fiber due to the thermal expansion force of the fixed type was as shown in Table 1.

Comparative Example 5

A molded article was obtained in the same manner as in Example 2 except that the epoxy resin impregnated with the carbon fiber bundle of the molded article was heat-treated at 60 for 90 minutes when thermally cured.

Comparative Example 6

A fiber reinforced resin composite reinforced material was produced in the same manner as in Example 2 except that no axial tensile force was applied to the core by the jig during the molding of the molded body. The heat curing treatment conditions at this time were the same as those in Example 2 at 150 ^eC for 60 minutes.

From the fiber-reinforced resin composite reinforcing bars of Example 2 and Comparative Examples 5 and 6 obtained as described above, rod-shaped test pieces 22 each having a length of about 1,500 mm were cut out, and as shown in FIG. In addition, 500 marauders at both ends of this specimen 22 Tensile tests were performed in which the metal fixing brackets 24 at both ends were fixed and fixed to the tubular metal fixing bracket 24 with the fixing material 23, and were pulled to the left and right until the mouth-shaped test piece was broken. The results are shown in Table 1.

As is clear from the results in Table 1, Comparative Example 5 showed a larger breaking load than Comparative Example 6, but the amount of strain was out of the range of the present invention. The strength of the composite bar deteriorated. Example 2 exhibited a larger breaking load than Comparative Example 5.

Table 1

Example 3

Similarly to the second embodiment, fabricating a modulus 3. 4 xi 0 ⁶ MPa of carbon fibers and Eboki sheet resin and Ficoll lame emissions Towai Ndi 55% fiber volume fraction in the ring method及beauty about 20 0 molded body Then, fix the jig on one side to the side wall of the curing furnace, attach a hydraulic jack to the other jig, and set the hydraulic pressure so that the amount of distortion of the molded body between the pair of jigs is 800 or more. With a jack, a tensile force of about 4.9 × 10 ⁴ N was applied, and in this state, only the molded body was heated at 150 ^{eC for} 60 minutes and cured.

The obtained molded body was subjected to a tensile test in the same manner as in Example 2 and Comparative Examples 5 and 6 above. As a result, the breaking load was 4.85 × 10 ⁵ N, which was a remarkably high value as compared with the above-mentioned comparative example 6 having no load.

Example 4 The elastic modulus is 3.4 x i0 ⁵ MPa ^, (^ (! Using a bundle of 6 carbon fibers and epoxy resin, it takes 30 times using a FW device (manufactured by B0LENZ & SCHAFER, Germany). FW method, formed about 3 m of core of about 020 with a fiber volume content of 55%, twisted 2.4 times (0.8 turns Zm), and then 12,000 carbon bundles of Z bundle The core was wound up with a bundle of four fibers.

The obtained core with protrusions is fixed in a metal bending mold with a bending radius of 15 m, and is heat-cured at 150 ° C for 1 hour.A hip with a bending radius of 15 m and a strain of 12000 / Zm due to tensile force A curved carbon fiber reinforced resin composite reinforced material was obtained.

Example 5

Using impregnated with epoxy resin elastic modulus 3.4 x l0 ⁵ MPa carbon O維yarn or prepreg, which Han drain-up method or a method using a braider apparatus, woven維体product content of 55% and about 200 core of Approximately 3 m is molded, and both ends of the core are tied and fixed to a jig 1 with a string, and this is attached to a FW device, and a 2.4-turn twist (0.8 rotation Zm) is inserted into the core. The area around the part is wrapped with 4 bundles of 12,000 carbon fiber bundles in the same manner as in Example 1 above, fixed in a metal bending mold with a bending radius of 15 m, and thermoset at 150 ° C for 1 hour. As a result, a bent carbon fiber reinforced resin composite bar having a bending radius of 15 m and an amount of strain of 1200 Zm due to tensile force was obtained.

Example 6

After winding with 4 bundles of carbon fibers of 12,000 Z bundles in the same forming procedure as in Example 1 above, a twist of 2.4 rotations (0.8 rotation Zm) was produced without causing separation in the same direction as the convex portion. It is fixed in a metal bending mold with a bending radius of 15 m, heat-hardened at 150 mm for 1 hour, and has a bending radius of 15 m and a strain of 12000 / Zm due to tensile force. I got

Note that the compacts obtained in Examples 4 to 6 had a concrete adhesive strength similar to that of Example 1 and a tensile strength similar to that of Example 2. there were. Industrial applicability

The fiber reinforced resin composite reinforcing material of the present invention can exhibit excellent concrete adhesion without deteriorating the strength of the core, and has many characteristics such as light weight, high corrosion resistance, and good machinability. It has both.

Further, according to the method of the present invention, a high-strength fiber-reinforced composite bar having a high guaranteed strength can be easily produced with extremely high productivity, and the original strength of the reinforcing fiber can be efficiently exhibited. As a result, the required strength can be developed with a smaller amount of fiber, the economical efficiency is excellent, and a large amount can be supplied to the market, and the spread thereof can be promoted.

Furthermore, according to the present invention, a bent high-strength fiber-reinforced resin composite reinforced material with high dimensional accuracy can be easily manufactured without deterioration in strength, and a curved radius of curvature of 2 m or more can be obtained. A high-strength fiber-reinforced resin composite reinforced material with high dimensional accuracy can be provided.

As a result, fiber-reinforced resin composites, whose demand is expanding as a substitute for rebar or PC steel wire, can be provided at low cost, and their use can be expanded over a wider range. Things.

Claims

The scope of the claims

1. a core portion and a tightening portion made of a thermosetting composition comprising a thermosetting resin and a reinforcing woven fiber bundle; the tightening portion forms a convex portion on the surface of the core portion

A fiber-reinforced resin composite reinforced material comprising the fiber-reinforced resin composite molded article as described above, wherein the molded article has a strain of 500 to 3000 zm due to tensile force;

2. The fiber-reinforced resin composite reinforcing material according to claim 1, wherein the reinforcing fiber bundle in the tightening portion has a twist of 10 to 50 rotations per meter.

3. The fiber-reinforced resin composite reinforcing material according to claim 1, wherein the tightening portion is spirally formed at an angle of 65 to 85 ° with respect to the axial direction of the core portion.

4. A core and a crimped portion composed of a thermosetting composition comprising a thermosetting resin and a reinforcing woven bundle; the crimped portion forms a projection on the surface of the core.

A fiber-reinforced resin composite molded article comprising the core having a twist, and the molded article having a strain of 500 to 3000 / Zm due to tensile force and being curved. Fiber reinforced resin composite muscle.

5. The fiber-reinforced resin composite reinforcing material according to claim 4, wherein the core has a twist of 0.5 to 1 rotation per 1 m.

6. The fiber-reinforced resin composite reinforced material according to claim 4, wherein the curvature of the core has a radius of curvature of about 2 to 20 m.

7. The fiber-reinforced resin composite reinforced material according to claim 1, wherein the wound portion is formed of a reinforcing fiber bundle containing at least one thermoset resin.

8. A core is formed by impregnating a thermosetting resin into a plurality of reinforcing woven bundles in which the fiber direction is oriented in the length direction. One of them is to wind a thermosetting resin-impregnated reinforcing woven bundle and form a convex part to produce a molded product; a strain of 500 to 3000 / Zm in the axial direction of the obtained molded product Performing a thermosetting treatment while applying a tensile force for imparting an amount; a method for producing a fiber-reinforced resin composite reinforced material comprising the above.

9. A core is formed by passing a reinforcing fiber bundle impregnated with thermosetting resin between the pins of a pair of jigs having a plurality of pins provided at both ends of the filament winding device. 9. The method for producing a fiber-reinforced resin composite reinforcing material according to claim 8.

10. The reinforcing fiber bundle impregnated with a thermosetting resin is wound around the surface of the core to form a convex part, and the reinforcing fiber bundle having a twist of 10 to 50 rotations per lm is used. The method for producing the fiber-reinforced resin composite reinforced material described in o

1 1. The molded body was fixed to both ends of a metal fixed mold using a pair of jigs arranged at both ends during molding of the core and the convex part of the molded body, and fixed to the metal fixed mold. The molded body is heated as it is to thermally cure the thermosetting resin impregnated in the reinforcing fiber bundle, and the thermal expansion force of the metal fixed mold caused by heating during this thermal curing causes the molded body to have a thickness of 500 to 3000 m. The method for producing a fiber-reinforced resin composite reinforcing material according to claim 8 or 10, wherein a tensile force for imparting a strain is applied.

12. A plurality of reinforcing fiber bundles in which the direction of the fibers is oriented in the length direction is impregnated with a thermosetting resin to form a core, and the obtained core is twisted; Winding a reinforcing fiber bundle impregnated with at least one thermosetting resin on the surface of the portion to form a convex portion to produce a molded product; the molded product is formed into a curved mold having a predetermined radius of curvature. And heat-curing the curved molded body to apply a tensile force giving a strain of 500 SOOO z Zm; a method of manufacturing a fiber-reinforced resin composite reinforcing bar comprising the above o

1 3. A core is formed by impregnating a thermosetting resin into a plurality of reinforcing fiber bundles in which the fiber direction is oriented in the length direction, and at least one thermoset is formed on the surface of the obtained core. Winding a reinforcing fiber bundle impregnated with a conductive resin to form a convex portion to produce a molded body; twisting the molded body in the same direction as the winding direction of the obtained molded body; Fixing the body in a curved mold having a predetermined radius of curvature, applying a thermosetting treatment to the curved molded body, and applying a tensile force for imparting a strain of 500 to 3000 jLt Zm; A method for producing a fiber-reinforced resin composite reinforced material.

14. A pair of jigs having a plurality of pins provided on both ends of the filament winding device and a fixing portion for fixing to the curved mold when forming the core portion. 14. The method for producing a fiber-reinforced resin composite reinforcing bar according to claim 12, wherein a reinforcing fiber bundle impregnated with a thermosetting resin is stretched between the pins to form a core.

15. The method for producing a fiber-reinforced resin composite reinforcing material according to claim 12 or 13, wherein a twist of 0.5 to 1 rotation per meter is applied to the core.

16. The method for producing a fiber-reinforced resin composite reinforcing material according to claim 12, wherein a curvature having a radius of curvature of about 2 to 20 m is added to the core.

17. The fiber according to claim 12, wherein the reinforcing fiber bundle is spirally wound around the surface of the core at an angle of 65 to 85 ° with respect to the axial direction of the core to form a tightened portion. A method for producing a reinforced resin composite reinforcing bar.

18. The thermosetting resin is an epoxy resin, a phenol resin, a polyamide resin, or the like, and the reinforcing fiber is a carbon fiber or arami such as a PAN-based, pitch-based, or high-printed-based resin. 5. The fiber-reinforced resin composite reinforced material according to claim 1, wherein the fiber-reinforced resin composite reinforced material is glass fiber, glass fiber or the like.

19. The reinforcing fibers are PAN-based, pitch-based, and hybrid-based carbon fibers, alkamide fibers, glass fibers, and the like, and the thermosetting resin is an epoxy resin, Phenolic resin, polyamide resin, etc. The method for producing a fiber-reinforced resin composite reinforcing bar according to the range 8, 12, or 13,