JPH01116144A - Manufacture of concrete reinforcing bar made of fiber reinforced plastic - Google Patents

Abstract

PURPOSE: To prevent sequential destructive breakage caused in the neighbourhood of a curved part by forming a concrete reinforcing bar by cutting an anchor bar at its central part after integrally forming a shearing reinforcing bar and the anchor bar. CONSTITUTION: An integral type reinforcing bar cage 8 is formed by sequentially engaging fiber reinforcing plastic made strings S with each other in the axial direction and in a direction orthogonal with an axis in such a way to draw a line while rotating them by a device. Thereafter, a concrete reinforcing bar 3 is made by cutting an anchor bar 5 orthogonal with a shearing reinforcing bar 4 of the reinforcing bar cage roughly at a central part of the shearing reinforcing bars 4 adjacent to each other. Thereafter, an axial bar 2 and the shearing reinforcing bar 4 are connected to each other after building the concrete reinforcing bar 3 in the axial bar 2 and arranging them with a specified interval.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a concrete reinforcing member made of fiber-reinforced plastic and suitable for use as a substitute for reinforcing reinforcing bars etc. buried in various concrete structures. .

[Conventional technology]

So-called fiber-reinforced plastics (hereinafter referred to as "FRP") have characteristics such as being lightweight, having high specific strength, excellent corrosion resistance, good moldability, and a high degree of freedom in shape.
It is used in various structural materials. In recent years, taking advantage of the above characteristics, various applications of concrete reinforcing members made by assembling bar-shaped FRP members in the same manner as reinforcing bar cages have been studied as an alternative to reinforcing reinforcing bars buried in various concrete structures. . - As an example, a concrete structure to be constructed is constructed by integrally molding a plurality of FRP shaft reinforcements extending in the axial direction and FRP shear reinforcing bars wound around the outer periphery of these shaft reinforcements. There are things etc. According to this concrete reinforcing member, quality control is done as a container because it is integrally molded in a factory, transport and construction work is extremely simple because it is lightweight, there is no need to take anti-corrosion and rust measures, etc. This provides excellent advantages.

However, the above-mentioned concrete reinforcing members also have the following problem: the shear reinforcing bars are bent at a sharp angle at the intersection with the axial bars, so it is difficult to bury the concrete reinforcing members. When tensile force in the axial direction acts on the shear reinforcing bars due to shearing force acting on the concrete structure, bending stress is generated locally at the intersection with the axial reinforcement (i.e. at the bend), and this axial reinforcement intersection The problem that ruptures of shear reinforcing bars at certain points would be sequentially destructive, resulting in much lower yield strength than in the case of all points, remained to be studied.

Therefore, the present applicant and others separately developed a concrete reinforcing member as shown in Figure 12. This concrete reinforcing member 1 is formed by forming at least three (four in the illustrated example) axial reinforcements 2 three-dimensionally arranged at intervals from each other and continuous fibers hardened with a resin material. Since it is composed of a plurality of concrete reinforcing bars 3 arranged around the axial bars 2, the concrete reinforcing bars 3 are
A shear reinforcing bar 4 that is wound around the axial bar 2 and has a bent part 4a at the intersection thereof, and the bent part 4a of this shear reinforcing bar 4.
It consists of an anchor reinforcement 5 extending in the vicinity in a direction substantially parallel to the axial reinforcement 2.

In the concrete reinforcing member l having such a configuration,
As shown in FIG.
When a load as shown by arrow A in the figure acts on a beam (concrete structure) 7 constructed by burying a concrete structure, the upper surface of the beam 7 becomes compressed and the lower surface becomes tensile. Therefore, an axial tensile force is applied to the shear reinforcing bars 4 in the section where the shear force of the reinforcing member l acts. However, this shear reinforcing bar 4 has a section extending in a direction perpendicular to the axial direction of this shear reinforcing bar 4 (a direction parallel to the axial bar 2) before the intersection with the axial bar 2, that is, the bending part 4a. By providing the anchor reinforcement 5, the shear reinforcing reinforcement 4 is strongly attached to the concrete 6 in the axial direction via the anchor reinforcement 5. Therefore, the tensile force acting in the axial direction of the shear reinforcement 4 is transmitted to the concrete 6 via the anchor reinforcement 5, and is hardly transmitted to the bent portion 4a of the shear reinforcement 4.

As a result, the sequential destructive fracture that conventionally occurs near the bent portion 4a is prevented as much as possible, and the tensile strength originally possessed by the shear reinforcing bars 4 can be fully exerted. This means that the yield strength can be significantly increased.

Furthermore, as shown in FIG. 14, the shear reinforcing bar 4 may be constructed by winding it around the axial bar 2 in a spiral manner. In this case as well, the helical shear reinforcing bar 4 is bent. By providing the anchor reinforcement 5 extending in a direction parallel to the axial reinforcement 2 near the portion 4a, it is possible to prevent sequential destructive breakage occurring near the bent portion 4a.

[Problem that the invention seeks to solve]

By the way, according to the concrete reinforcing bars 3, although it is possible to obtain the excellent effects as described above, the following issues remain to be investigated.

That is, when producing the concrete reinforcing bars 3 as shown in FIGS. 12 and 14 above, it is necessary to use the method that would probably be taken if these were steel materials such as reinforcing bars, that is, loop-shaped or spiral reinforcements. Shear reinforcing bars 4 in the shape of
The anchor bars 5 attached to the shear reinforcing bars 4 may be manufactured separately in advance, and the anchor bars 5 may be attached to the shear reinforcing bars 4 later by some method, or as shown in Figure 15. As shown, in particular, when the shaft reinforcement 2 is also made of FRP by taking advantage of the good formability of FRP and is constructed integrally with the concrete reinforcing reinforcement 3, the anchor reinforcement 5 is replaced with the shear reinforcement reinforcement 4. One possible method is to integrally mold the FRP and then delete the unnecessary part 5a, but the former is extremely unreasonable and does not utilize the good moldability of FRP at all, and the latter is an extremely unreasonable method as described above. axis muscle 2
This method is effective when the entire concrete reinforcing member l including the reinforcing bars 1 is made of FRP, but when the axial reinforcements 2 and reinforcing bars 3 are constructed separately, an unnecessary portion 5a is created. This results in the disadvantage that there are many cutting points and it becomes uneconomical.

The present invention was developed in view of the above circumstances, and an object of the present invention is to provide a method for efficiently manufacturing concrete reinforcing bars made of fiber-reinforced plastic that exhibits the excellent effects as described above and without waste. be.

[Means for solving problems]

A first invention provides a plurality of axial reinforcements embedded in the longitudinal direction of a concrete structure, and a plurality of axial reinforcements are installed at predetermined intervals in a direction substantially perpendicular to the axial reinforcements, with the intersections with the axial reinforcements being bent parts. A method for producing concrete reinforcing bars made of fiber-reinforced plastic, comprising a shear reinforcing bar, and an anchor bar extending in the vicinity of the bent portion of the shear reinforcing bar in a direction substantially parallel to the axial bar, the method comprising: The shear reinforcing bars are formed into a state in which the plural shear reinforcing bars are connected together by the anchor bars at intervals equal to the length of the anchor bars, and then the plural shear reinforcing bars are connected. This method is characterized in that the anchor reinforcement is formed by cutting it approximately at the center of the adjacent shear reinforcing reinforcement.

Moreover, the second invention is provided by winding the concrete structure in a spiral manner in a direction substantially perpendicular to the plurality of axial reinforcements buried in the longitudinal direction of the concrete structure, with the intersections with the axial reinforcements being bent parts. A method for manufacturing concrete reinforcing bars made of fiber-reinforced plastic comprising shear reinforcing bars and anchor bars extending in the vicinity of the bent portions of the shear reinforcing bars in a direction substantially parallel to the axial bars, the method comprising: After forming the shear reinforcing bars integrally with the anchor bars at a pitch equal to the length of the anchor bars, the shear reinforcing bars are formed integrally with the helical shear reinforcing bars. After cutting at approximately the center of the pitch to be formed, the shear reinforcing bars are pulled in the axial direction of the spiral formed by themselves to set a predetermined pitch.

[Operation] In the first invention, the shear reinforcing bars and the anchor bars are formed so that the shear reinforcing bars are integrally formed with the anchor bars with an interval equal to the length of the anchor bars, and then the shear reinforcing bars are If the anchor bars to be connected are cut at approximately the center thereof, a shear reinforcing bar having the required anchor bars, that is, a target concrete reinforcing bar is formed.

In the second invention, after forming the spiral shear reinforcing bars integrally with the anchor bars and at a pitch equal to the length of the anchor bars,
By cutting the anchor reinforcement integrated with the spiral shear reinforcement at approximately the center of the pitch, the spiral shear reinforcement with the required anchor reinforcement, that is, the desired concrete reinforcement, is formed. .

〔Example 〕

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 8 illustrate an embodiment of the first invention according to the present invention, in which the concrete reinforcing bars 3 shown in FIG. In a direction almost perpendicular to the plurality of axial reinforcements 2,
A plurality of shear reinforcing bars 4 are attached at predetermined intervals in a wound state with the intersection with the axial reinforcement 2 as a bent part 4a, and a shear reinforcing bar 4 that is approximately parallel to the axial reinforcing bar 2 near the bent part 4a of the shear reinforcing bar 4. This figure shows a method for producing concrete reinforcing bars made of fiber-reinforced plastic and consisting of anchor bars 5 extending in different directions. The concrete reinforcing bars 3 are manufactured according to the following steps.

First, as shown in FIG. 1, a plurality of shear reinforcing bars 3 are
An integral reinforcing bar 8 is manufactured in which the shear reinforcing bars 3 are separated by a length Q of the anchor bars 5 and are integrally connected by the anchor bars 5.

This integrated reinforcing myoelectric device 8 can be manufactured using, for example, a device as shown in FIGS. 2 and 3. In these figures, reference numeral 10 denotes a rotating shaft, and reference numeral 11 denotes guide rods extending radially around the rotating shaft 10 and arranged in parallel in the axial direction of the rotating shaft IO with the dimension e apart.
Reference numeral 2 denotes a bifurcated guide claw provided at the tip of each guide rod 11, which is extendable and retractable in the axial direction of the guide rod 11. Regarding the manufacturing method, please refer to String S made of fiber reinforced plastic.
, while rotating the rotating shaft 10, the corresponding guide claw 1
2, in a so-called one-stroke manner, by sequentially engaging and hooking it in the axial direction and in the direction perpendicular to the axis. here,
The string S hanging in the axial direction constitutes the anchor reinforcement 5, and the string S hanging in the direction perpendicular to the axis constitutes the shear reinforcement 4.

Here, the string S made of fiber-reinforced plastic that constitutes the integrated reinforcing myoelectric device 8 will be explained. As shown in FIG.
3 are bound together by a resin material 14. As the continuous fibers 13, glass fibers, carbon fibers, etc., which are lightweight and have high strength, are suitable, but if necessary, other fibers such as synthetic resin fibers, ceramic fibers,
Metal fibers may also be used. Further, these fibers may be appropriately combined. Further, as the resin material 14, a resin that has good adhesion to these continuous fibers 13 and has sufficient strength itself, such as vinyl ester resin, is suitable, but it depends on the type of continuous fibers 13 used. Alternatively, other resin materials may be used. Other resin materials include unsaturated polyester resins, epoxy resins, phenol resins, and the like. The ratio of the resin material 14 to the continuous fibers Qft13 is determined appropriately taking into consideration the type and strength of the continuous fibers 13, the usage form of the concrete reinforcing bars 3, etc. For example, if the continuous fibers 13 are glass When the fiber or resin material 14 is vinyl ester resin, the volume ratio of the continuous fibers 13 is about 30 to 70%, and when the continuous fibers 113 are carbon fiber, for example, the volume ratio is about 20 to 60%. It is preferable to take this into account. That is, if the proportion of continuous fibers 13 is below the above, the strength of the concrete reinforcing bars 3 will decrease significantly, and -
The higher the proportion of continuous fibers 13, the higher the strength of the reinforcing bar 3, but if the proportion is too high, it is not preferable from an economic point of view when using relatively expensive materials such as carbon fibers.

When such a string S is assembled into the above-mentioned integrated reinforcing bar cage 8, the portions constituting the shear reinforcement bars 4 and the portions constituting the anchor bars 5 intersect. As shown in FIG. It has been integrated into. In addition, in order to ensure strength, the intersections of the strings S are
As shown in the figure, the cross-sectional shape is such that the intersecting strings S are alternately stacked in at least three or more layers (in the illustrated example, 4Ii).

Now, once the integral reinforcing bar cage 8 as described above is manufactured, anchor bars 5 which extend in a direction perpendicular to the shear reinforcing bars 4 arranged in a ribbed manner and connect the shear reinforcing bars 4 together
As shown in FIG. 6, the shear reinforcing bars 4 that are adjacent to each other are cut approximately at the center. As a result, as shown in FIG. 7, a plurality of concrete reinforcing bars 3 are formed in the vicinity of the bent portion 4a and provided with anchor bars 5 extending in a direction orthogonal to the shear reinforcing bars 4. Here, each shear reinforcing bar 4
are formed apart from each other by a dimension Q at the stage of fabrication of the integrated reinforcement 71B, so the anchor bars 5 of the concrete reinforcement 3 formed as described above have dimensions Q. Therefore,

Thereafter, after incorporating the concrete reinforcing bars 3 into the shaft reinforcements 2 and arranging them at predetermined intervals as shown in FIG.
and the shear reinforcing bars 4 may be bound together using, for example, a steel wire for binding. Note that when producing individual concrete reinforcing bars 3 by cutting the integrated reinforcing myoelectric 8, the eighth
As shown in the figure, an axial muscle 2 for the purpose of integrated reinforcing myoelectricity 8
It may be carried out after being installed in advance.

According to the above manufacturing method, a plurality of concrete reinforcing bars 3 are made up of shear reinforcing bars 4 and anchor bars 5 extending in the vicinity of the bending part 4a of the shear reinforcing bars 4 in a direction perpendicular to the shear reinforcing bars 4. can be produced extremely easily and efficiently. In addition, individual concrete reinforcing bars 3 are produced by cutting the integrally molded material, but at that time, there are no removed parts, that is, parts that should be discarded, and relatively expensive materials are used. (Fiber reinforced plus deck) is not wasted.

Next, FIGS. 9 to 11 show an embodiment of the second invention according to the present invention, in which the reinforcing bars 3 shown in FIG. , a shear reinforcing bar 4 spirally wound around the intersection with the axial bar 2 as a bending part 4a, and a shear reinforcing bar 4 in the vicinity of the bending part 4a in a direction substantially parallel to the axial bar 2. A method for producing concrete reinforcing bars made of fiber-reinforced plastic and consisting of extended anchor bars 5 is shown. This concrete reinforcing bar 3 is produced as follows.

First, as shown in Fig. 9, the helical shear reinforcement 4
is the pitch corresponding to the length of the anchor reinforcement 5, that is, the dimension Q
An integral reinforcing bar 8 is manufactured so that the shear reinforcing bars 4 are integrated with the anchor bars 5 and the pitch thereof is restricted by the anchor bars 5.

This integrated reinforcing myoelectric device 8 can be manufactured using, for example, the apparatus shown in FIGS. 2 and 3, similar to that described in the embodiment of the first invention. Also,
The manufacturing process is also the same.

In other words, a string S made of fiber reinforced plastic is
While rotating the rotating shaft IO, the same string S is wound spirally around the corresponding guide claw 12, and the same string S is wound in a direction perpendicular to the string S forming the spiral.
Hook it while engaging it one by one in the same way as when writing with a brush. Here, the string S wound in a spiral configuration constitutes the shear reinforcing bar 4, and the string S provided in a direction substantially perpendicular to the string S forming the spiral constitutes the anchor bar 5. . String S like this
At the intersection of the part constituting the shear reinforcing bar 4 and the part constituting the anchor bar 5, the continuous fibers 13 constituting both strings S are merged and fixed, and the continuous fibers 113 of both are By being bound together by a common resin material 14, they become completely integrated.

In order to ensure strength, the intersection of the strings S has a cross-sectional shape in which at least three or more layers of intersecting strings S are stacked alternately.

Once the integral reinforcing bar 8 as described above is manufactured, a string S (shear reinforcing bar 4) formed in a spiral with a pitch Q is formed.
As shown in FIG. 10, anchor bars 5 that are integral with the shear reinforcement bars 4 and extend in a direction substantially orthogonal to the shear reinforcement bars 4 to restrain the helical pitch of the shear reinforcement bars 4 are adjacent to each other with a pitch a apart therebetween. The shear reinforcing bar 4 is cut approximately at the center. As a result, the bent portion 4a as shown in FIG.
Concrete reinforcing bars 3 are formed in the vicinity thereof with anchor bars 5 extending in a direction substantially orthogonal to the shear reinforcing bars 4. Here, since the cutting reinforcing bars 4 are formed in a spiral shape with a pitch Q at the stage of fabricating the integrated reinforcing myoelectrics 8, the anchor bars 5 of the concrete reinforcing bars 3 formed as described above are has a length of Q.

After that, after incorporating these concrete reinforcing bars 3 into the axial reinforcement 2, the shear reinforcement 4 is pulled in the axial direction of the spiral formed by itself, that is, in the longitudinal direction of the axial reinforcement 2, using a jig to perform shear reinforcement. The reinforcement bars 4 are set at a required pitch, and the shear reinforcing bars 4 are
and the shaft reinforcement 2 may be bound using, for example, a steel wire for binding. In addition, when cutting the part that will become the anchor reinforcement 5 of the integrated reinforcing myoelectric device 8, as shown in FIG. Good too.

According to the above manufacturing method, the fiber reinforcement is composed of a spiral shear reinforcing bar 4 and an anchor bar 5 extending in the vicinity of the bent portion 4a of the shear reinforcing bar 4 in a direction substantially orthogonal to the shear reinforcing bar 4. Plastic concrete reinforcing bars 3 can be produced extremely easily and efficiently. In addition, after integral molding, anchor bars 5 that restrain the helical pitch of the shear reinforcing bars 4 are added.
By cutting the target concrete reinforcement 3
At that time, there are no parts to be removed, that is, no parts to be discarded, and no material is wasted.

〔Effect of the invention〕

As explained above, according to the present invention, fiber-reinforced plastic concrete reinforcement can prevent sequential destructive fractures that occur near bends and can fully utilize the tensile strength inherent in shear reinforcing bars. This method has excellent effects such as being able to create streaks extremely simply and efficiently without wasting material.

[Brief explanation of the drawing]

Figures 1 to 8 are for explaining an embodiment of the first invention according to the present invention, in which Figure 1 is a perspective view of an integrated reinforcing bar, and Figure 2 shows an outline of the manufacturing device. 3 is a side view thereof, 4 is a sectional view of a string made of fiber-reinforced plastic, 5 is a sectional view at the intersection of the strings, and 6 is a perspective view of an integral reinforcing bar. , FIG. 7 is a perspective view of concrete reinforcing bars, and FIG. 8 is a perspective view showing an integrated reinforcing bar together with shaft bars. 9 to 11 illustrate an embodiment of the second invention according to the present invention, and FIG.
Figures 1 and 10 are perspective views showing an integrated reinforcing bar;
FIG. 1 is a perspective view showing the integrated reinforcing bar together with the shaft bar. 12th
15 to 15 are for explaining concrete reinforcing bars separately invented by the present applicant. FIG. 12 is a perspective view of a concrete reinforcing member, FIG. 13 is a cross-sectional view of a concrete structure showing its function, and FIG. Figures 1 and 15 are perspective views of the concrete reinforcing member. 2... Axial reinforcement, 3... Concrete reinforcement, 4... Shear reinforcement, 4a...
・Bending part, 5...Anchor muscle, 8...
...Integrated reinforcement myoelectric.

Claims (2)

[Claims] (1) Shear reinforcement that is installed at predetermined intervals in a direction substantially perpendicular to multiple axial reinforcements buried in the longitudinal direction of the concrete structure, with the intersections with the axial reinforcements being bent parts in a wound state. A method for manufacturing concrete reinforcing bars made of fiber-reinforced plastic comprising a reinforcement bar and an anchor bar extending in a direction substantially parallel to the axial bar near the bent portion of the shear reinforcing bar, the method comprising: After forming the reinforcing bars so that the plurality of shear reinforcing bars are connected together by the anchor bars at intervals equal to the length of the anchor bars,
A method for producing concrete reinforcing bars made of fiber-reinforced plastic, characterized in that the anchor bars connecting the plurality of shear reinforcing bars are formed by cutting them at approximately the center of adjacent shear reinforcing bars. (2) shear reinforcing bars installed in a direction substantially orthogonal to the plurality of axial bars buried in the longitudinal direction of the concrete structure, spirally wound around the intersections with the axial bars as bent parts; A method for producing a fiber-reinforced plastic concrete reinforcing bar comprising an anchor bar extending in a direction substantially parallel to the axial bar near the bending part of the shear reinforcing bar, the method comprising:
After forming the helical shear reinforcing bars integrally with the anchor bars at a pitch equal to the length of the anchor bars, the anchor bars integrated with the helical shear reinforcing bars are sheared. A concrete made of fiber-reinforced plastic, characterized in that the pitch is set at a predetermined pitch by cutting the reinforcing bars at approximately the center of the pitch formed by the reinforcing bars, and then pulling the shear reinforcing bars in the axial direction of the spiral formed by the shear reinforcing bars. How to make reinforcing bars.