JP4037041B2 - Terminal processing method and terminal fixing method of fiber composite material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a terminal processing method and a terminal fixing method of a rope-like or cable-like fiber composite material using high strength and low elongation fibers.
[0002]
[Prior art]
A fiber composite material formed by impregnating a thermosetting resin into a high-strength low elongation fiber and curing it to form a rod-like body, a linear body, a twisted body, or the like is disclosed in Japanese Patent Publication Nos. 57-25679 and 62-18679. It is known from the gazette.
A rope-like or cable-like fiber composite material using such high strength and low elongation fibers is lightweight, excellent in corrosion resistance, high strength, low elongation, low relaxation, etc. Has chemical properties. For this reason, it tends to be used, for example, as a tension material for prestressed concrete, a tension material for concrete by a pretension system and a post tension system, or an out cable as a material to replace conventional steel wires and wire ropes.
[0003]
In such use, it is important to process the terminal portion of the fiber composite material so that it can be fixed to the fixing portion reliably and with good workability at low cost.
Conventionally, in general fiber ropes, when fixing the terminal portion, a method of applying ice price or splicing ropes to each other has been adopted. Although these methods can be applied in the case of a rope configuration that is flexible and easy to untwist, it is difficult to apply to a fiber composite material in which high-strength low-stretch fibers are collectively cured with a thermosetting resin.
[0004]
Therefore, it would be advantageous if a rust prevention method could be adopted as is widely used in wire ropes. However, since the material of the fiber composite material is a fiber, the fiber composite material has a high strength against a tensile force in the longitudinal direction but is weak against a shearing force in the diameter direction. For this reason, when applying the fixing method of the wedge type applied to the wire rope to the fiber composite material, a strong shearing force is applied to the fiber composite material from the inner peripheral edge of the cone by the wedge action of the cone, and the constituent fiber There was a problem that breakage occurred and stable fixing became difficult.
[0005]
For this reason, conventionally, as a fixing method, the end portion of the fiber composite is inserted into a die-casting die, and a compression force is applied to the fixing portion from the outer periphery by a press machine so that the fixing portion is sandwiched between a plurality of split cones. Insert into the sleeve and fix the fiber composite by wedge action, or insert it into the die-casting die of the fiber composite and inject and solidify the low melting point metal into the die. Insert the coated end part into the pipe, press the crimping part to the fixing part from the outer periphery with a press machine, press the fixing part with multiple cones, insert it into the sleeve, and wedge the fiber composite material A method of fixing by action is known.
[0006]
However, the fixing method as described above is complicated in process, takes time and labor, and is practically difficult to process at the site of use. In addition, the outer diameter of the terminal processing portion becomes very large. For this reason, the post-tension method or the like is not easy to insert into the sheath, and requires a large fixing space, which is not efficient and economical.
[0007]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-mentioned problems, and the object of the present invention is that it can be integrated with a fiber composite material and can have a small outer diameter, and can be easily used at a construction site. It is providing the terminal processing method of the fiber composite material which can be implemented.
Another object of the present invention is to provide a terminal fixing method for a fiber composite material which can easily and quickly have a relatively small outer diameter and can exhibit a high fixing force on site.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention embeds a fiber bundle between the strands of the twisted wire-shaped end portion of the fiber composite material in which the high-strength low-stretch fiber and the thermosetting resin are combined, and the outer periphery of the fiber bundle is in this state. The fiber composite material and the fiber bundle are integrally joined by wrapping with a bundle and forming into a cylindrical shape, then impregnating a thermosetting resin equivalent to the matrix resin of the fiber composite material and heating.
[0009]
It is preferable to use a high-strength, low-elongation fiber made of the same material as the fiber composite material as a fiber bundle to be buried in the valley of the stranded wire at the end of the fiber composite material. It is also preferable to use a heat-shrinkable fiber as a fiber bundle used for wrapping, and to bind the fiber bundle embedded in the valley of the stranded wire and the fiber composite material end portion by the heat-shrinking action of the fiber during heating.
[0010]
According to the present invention, the fixing portion of the fiber composite material obtained as described above is sandwiched between a plurality of wedges and inserted into a sleeve, and the fixing portion is fixed to the fixing portion by a wedge action. It is a feature.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 7 show the steps of a fiber composite material terminal processing method according to the present invention. In FIG. 1, reference numeral 1 denotes a cable-shaped fiber composite material in which high-strength low-stretch fibers and a thermosetting resin are combined. is there. This fiber composite material 1 is formed by twisting a plurality of composite strands 1a into a structure of 1 × 5, 1 × 7, 1 × 19, 1 × 24, or the like.
[0012]
The composite strand 1a is a heat selected from an epoxy resin, an unsaturated polyester resin, a polyurethane resin, etc. into a fiber bundle in which a number of high strength and low elongation fibers selected from carbon fiber, polyaramid fiber, silicon carbide fiber, etc. are converged. It consists of a composite material impregnated with a curable resin. In this example, the outer layer is coated with high-strength low elongation fiber or synthetic fiber yarn such as polyester.
[0013]
The fiber composite material 1 is formed by impregnating each composite strand 1a, 1a with a shaping die or the like and removing excess resin, and then applying a powder desiccant such as talc on the surface to dry the surface, followed by impregnation thermosetting The thermosetting resin is made by twisting together at a predetermined pitch in an uncured stage, and then heating to cure the thermosetting resin.
Each of the composite strands 1a is twisted at a predetermined pitch when the impregnated thermosetting resin is uncured, and then heated to cure the thermosetting resin, thereby producing the fiber composite material 1.
[0014]
In the present invention, first, as shown in FIG. 3, the valleys of the stranded wire constituting the outer periphery of the terminal portion 1 ′ in a predetermined range to be the fixing portion of the fiber composite material 1, that is, the adjacent composite strands 1 a and 1 a The fiber bundles 3 and 3 are embedded in the valleys 2 and 2.
As shown in FIGS. 2 (a) and 2 (b), the fiber bundle 3 is a bundle of high strength and low elongation fibers 30 made of the same material as the fiber composite material. It is impregnated with a thermosetting resin 5 selected from resin, unsaturated polyester resin, polyurethane resin, etc., molded with a shaping die, etc., and excess resin is removed. From the handling aspect, dry powder such as talc. It is preferable that the surface is dried by applying an agent.
[0015]
When the thermosetting resin is impregnated in this way, it is permanently deformed with an appropriate pressing force, so that the gap between the strands 2 and 2 of the composite strands 1a and 1a is instantly adapted to each shape perpendicular to the longitudinal direction and the longitudinal direction. Since it can be filled without any problem and it is temporarily fixed in close contact with the composite strands 1a and 1a due to light adhesiveness, it can be prevented from coming off without raising the special holding means.
The thickness of the cross section of the fiber bundle 3 should be equal to or greater than the valley of the composite strands 1a and 1a in FIG. The cross-sectional shape may be round, or may be previously formed into a fan shape or a triangular shape.
[0016]
Next, in the present invention, the entire cross section as shown in FIGS. 5B and 5C is formed on the outer periphery of the first stage processing terminal portion A in which the fiber bundle 3 is embedded in each of the twisted valleys 2 and 2 as described above. The fiber bundle 4 is tightly wound spirally so as to exhibit a circular shape.
As shown in FIG. 4, the fiber bundles 40 are aligned in parallel, and the entire fiber bundle 4 has a belt shape, and is wound so that there is no gap between winding turns or overlap. As the fiber yarn constituting the fiber bundle 4, heat-shrinkable fibers such as polyester fibers are suitable.
In the fiber bundle 4, the thickness and the number of the fiber yarns 40 are set so that the second stage processing terminal portion B after the winding of the fiber bundle 4 is about 1.1 times or less the outer diameter of the fiber composite material 1. .
[0017]
Next, as shown in FIG. 6, the second stage processing terminal B is selected from the same or equivalent thermosetting resin as the matrix resin of the fiber composite material 1, that is, an epoxy resin, an unsaturated polyester resin, a polyurethane resin, or the like. Impregnated with resin (liquid) 5.
For example, the impregnation may be performed by inserting the second stage processing terminal B into the thermosetting resin 5 accommodated in the container 8 as shown in FIG. Spray is optional. The thermosetting resin 5 is impregnated into the fiber yarns 40 of the fiber bundle 4 and the permeate is adhered to the outer surface of the fiber bundle 3 and the outer surfaces of the composite strands 1a and 1a. This becomes the third stage processing terminal part C.
[0018]
Next, the third stage processing terminal C is heated in this state. The heating temperature is a temperature sufficient for curing the thermosetting resin, for example, 100 ° C. to 130 ° C. The fiber bundles 3 and 3 embedded in the valleys of the composite strands 1a and 1a are impregnated by the heating. The outer surface of each composite strand 1a, 1a is bonded to each composite strand 1a, 1a by the thermosetting resin 5 and the thermosetting resin impregnated in the third stage with the fiber bundle 4 wound around the outer periphery. And it adhere | attaches on the outer surface of the fiber bundles 3 and 3, and it hardens | cures in this state.
The heating and heating means is arbitrary, for example, a pipe is used, and the third stage processing terminal C is loosely inserted into the pipe, and hot air is blown into the pipe to control temperature and time, or a third electric heater is installed in the cylindrical electric heater. What is necessary is just to manage the temperature and time by inserting the stage processing terminal part C.
[0019]
The fiber bundles 3 and 3 are made of high-strength, low-elongation fibers of the same quality as the fiber composite material 1, and the thermosetting resin 5 as an adhesive is also the same material as the matrix resin of the fiber composite material 1. The buffer layer composed of the fiber bundles 3 and 3 and the fiber bundle 4 having the same characteristics is completely integrated with the fiber composite material 1, so that the fixing section having a circular cross section as shown in FIG. D is completed. 5 ′ is a thermosetting resin impregnated and cured.
[0020]
When heat-shrinkable fibers are used as the constituent fibers of the fiber bundle 4, the shrinkage is caused by the heating, so that the diameter of the cylindrical shape by the winding is reduced and the fiber composite material 1 is in close contact. For this reason, adhesion with the composite strands 1a and 1a is ensured, and the fiber bundles 3 and 3 of the fiber composite material 1 can be firmly restrained and tightly integrated with them. Accordingly, it is possible to obtain a fixing portion D having a small diameter increase rate with respect to the diameter of the fiber composite material 1.
[0021]
Next, for fixing, as shown in FIG. 8A, the fixing portion D is inserted into the sleeve 6 made of iron or the like, and is sandwiched between a plurality of split wedges 7 and 7, and in this state, together with the split wedges 7 and 7 Insert it into the sleeve 6 and stop it from being wedged.
[0022]
Since the fixing portion D is a cylindrical buffer layer composed of the fiber bundles 3 and 3 in which the twisted valleys of the composite strands 1a and 1a are filled and the fiber bundle 4 surrounding them, a wide contact area with the wedge is taken. And stable fixing can be achieved. Moreover, the fiber bundles 3 and 3 filling the twisted valleys of the composite strands 1a and 1a are made of the same material, and the matrix resin of the composite strands 1a and 1a and the resin as an adhesive impregnated in the fiber bundles 3 and 3 are also the same. Because it is made of a material, physical properties such as strength, tensile strength, and elastic modulus are equivalent and strong integration is obtained, so that local compressive shear force due to wedge action can be stably received on the surface. Therefore, compression shear failure is prevented and the fixing function can be increased. Since rust prevention is possible in this way, the outer diameter of the fixing portion E can be made relatively small.
[0023]
Further, since the outer diameter of the fixing portion D is small and the fiber composite material 1 needs only to be slightly increased, it is not necessary to increase the sheath diameter when the fiber composite material 1 is passed through the sheath. Since the number of sheaths can be increased, high strength concrete can be made when used as a tendon.
[0024]
In addition, the whole fiber composite material 1 of this invention does not necessarily need to be a twisted structure. That is, the portion other than the terminal portion 1 ′ may have a structure in which strands are bundled in parallel.
[0025]
Specific examples of the present invention will be described.
As the fiber composite material 1, seven composite strands having a diameter of 4 mm made of a composite material of carbon fiber and epoxy resin were used, and one having a 1 × 7 structure twisted at a twist pitch of 150 mm and having an outer diameter of 12.5φ was used. The standard breaking value of this fiber composite material 1 was 142 kN.
[0026]
A carbon fiber bundle having a diameter of 2.2 mm impregnated with an epoxy resin was applied along each spiral valley of the strand of the end portion 270 mm of the fiber composite material 1 and embedded with finger pressure. A bundle of 12000 denier polyester fibers was flattened to a width of 10 mm from above and uniformly wound and restrained. After being immersed in a container containing an epoxy resin in this state, it was inserted into a pipe-shaped heater, heated with hot air and heated at 130 ° C. for 2 hours. As a result, a fixing portion in which the buffer layer and the fiber composite material were cured and integrated was obtained. The outer diameter of the fixing portion was 13.8 mm.
[0027]
The obtained fixing portion was sandwiched between two wedges having a length of 150 mm, and inserted into an iron sleeve having an outer diameter of 48 mm to obtain a fixing portion.
The obtained cable with a fixing portion was subjected to a tensile test to measure fixing efficiency. As a result, a good result was obtained that the fracture position was a mouth fracture, the fracture load was 179 kN, and the fixing efficiency was 123% exceeding the standard fracture load.
[0028]
For comparison, a buffer sheet made of a composite of rubber and fiber and having a concavity and convexity having the same pitch as the spiral shape of the fiber composite material 1 on one side is used. A fixing part having a layer was obtained. The outer diameter of the fixing portion is 15.0 mm, and the diameter of the fixing portion is larger than that of the present invention.
The buffer sheet is made by using a metal mold in which a non-woven fabric using short aramid fibers and aramid fiber multifilament yarns are impregnated with an SBR adhesive rubber latex in advance and grooves having a constant interval on one side. The core is sandwiched between non-woven fabrics, baked at 100 ° C. for 15 minutes, and further vulcanized at 150 ° C. for 30 minutes to obliquely cut a sheet in which the fiber core and the non-woven fabric are integrated to a width of 25 mm.
[0029]
The comparative product was wedge-proofed as in the present invention to form a fixing portion, and the fixing efficiency of the cable with the fixing portion was measured. As a result, the breaking load was 156 kN and the fixing efficiency was 110%, which was inferior to the present invention. The reason is considered to be that there is a problem in the integration with the fiber composite material 1 because the buffer sheet with ridges is wound.
[0030]
【The invention's effect】
According to claim 1 of the present invention described above, the fiber bundle 3 is embedded in the valley of the stranded wire of the stranded wire-shaped terminal portion 1 ′ of the fiber composite material 1 in which the high-strength low elongation fiber and the thermosetting resin are combined, In this state, the outer periphery is lapped with a fiber bundle 4 to form a cylindrical shape, and then impregnated with a thermosetting resin 5 equivalent to the matrix resin of the fiber composite material 1 and heated, thereby heating the fiber composite material 1 and the fiber bundle 3. , 4 are joined together to obtain a fixing terminal processing part, so that a compact fixing part with a small degree of increase in diameter can be easily processed by a simple operation at the site. Since a large contact area can be secured, more stable fixing is possible. In addition, since the diameter of the fixing terminal processing portion is small, when the fiber composite material is passed through the sheath, the sheath diameter does not need to be increased and the space of the fixing portion can be reduced. It is done.
[0031]
According to claim 2, the fiber bundle 3 and the fiber composite, in which heat-shrinkable fibers are used as the fiber bundle 4 for wrapping, and the cylindrical diameter is reduced by the heat-shrinking action of the fibers during heating and embedded in the valleys of the stranded wires. Since the end portion of the material 1 is tightly bound, it is possible to obtain an excellent effect that the integration by adhesion is more sure and the diameter increase can be reduced.
[0032]
According to the third aspect, since the high strength and low elongation fiber of the same material as the fiber composite material 1 is used as the fiber bundle 3 filling the valley of the stranded wire of the terminal portion 1 ′, the physical characteristics are uniform and integrated. An excellent effect is obtained that an excellent fixing terminal processing portion can be obtained. According to the fourth aspect, the processing terminal portion D made in the first to third aspects is sandwiched between the plurality of wedges 7 and 7 and inserted into the sleeve 6 and fixed to the fixing portion by the wedge action. It can be easily constructed without requiring special tools on site, and the processing terminal portion D is cylindrical, and the material and mechanical properties of the fiber composite 1 are uniform and integrated. Therefore, the excellent effect that the local compressive shearing action received from the wedge chuck is dispersed on the surface and stable high fixing efficiency can be obtained.
[Brief description of the drawings]
FIG. 1A is a partial side view showing an example of a fiber composite material according to the present invention, and FIG. 1B is a cross-sectional view thereof.
FIG. 2A is a partial perspective view of a fiber bundle that fills a stranded valley, and FIG. 2B is a cross-sectional view thereof.
FIGS. 3A and 3B are side views of a stranded line valley filling stage, FIG. 3B is an enlarged sectional view thereof, and FIG. 3C is a partially enlarged view thereof.
FIG. 4 is a partial perspective view showing a fiber bundle for lapping in the present invention.
5A is a side view of a lapping stage, FIG. 5B is an enlarged sectional view thereof, and FIG. 5C is a partially enlarged view thereof.
FIG. 6 is a side view showing a thermosetting resin application step of the present invention.
7A is a cross-sectional view of the obtained fixing portion, and FIG. 7B is a partially enlarged cross-sectional view thereof.
8A is an explanatory diagram of a fixing process, and FIG. 8B is a side view showing a fixing completion state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fiber composite material 1 'End part 2 Valley 3 Fiber bundle 4 Fiber bundle 5 Thermosetting resin D Fixing part

Claims (4)

The fiber bundle 3 is embedded in the valley of the twisted wire-shaped end portion 1 ′ of the fiber composite material 1 in which the high-strength low elongation fiber and the thermosetting resin are combined, and the outer periphery is wrapped with the fiber bundle 4 in this state. It is formed into a cylindrical shape, and then impregnated with a thermosetting resin 5 equivalent to the matrix resin of the fiber composite material 1, and the fiber composite material 1 and the fiber bundles 3 and 4 are joined together by heating. End processing method of fiber composite material. A heat-shrinkable fiber is used as the fiber bundle 4 for wrapping, and the fiber bundle 3 embedded in the valleys of the stranded wire by shrinking the cylindrical diameter by the heat-shrinking action of the fiber during heating is tightly bound to the end portion of the fiber composite 1 The terminal processing method of the fiber composite material according to claim 1. The fiber composite material terminal processing method according to claim 1 or 2, wherein high-strength, low-elongation fibers made of the same material as the fiber composite material 1 are used as the fiber bundles 3 buried in the valleys of the stranded wires of the terminal portion 1 '. The processing end portion D of the fiber composite cable obtained in claims 1 to 3 is sandwiched by a plurality of wedges 7 and inserted into the sleeve 6 and fixed to the fixing portion by the wedge action. A terminal fixing method for a fiber composite material.

Images