JP2023181242A - Method for forming steel bar insertion hole of precast member, precast member joining method and precast member production method - Google Patents

Abstract

To provide: a method for forming a steel bar insertion hole of a precast member which makes the boundary of the steel bar insertion hole into a finish sufficient for expecting adhesion force to a steel bar without using a spiral type sheath tube and can realize cost reduction; a precast member joining method of inserting a steel bar into the steel bar insertion hole so as to be securely fixed; and a precast member.SOLUTION: Provided is a method for forming a steel bar insertion hole of a precast member in which a single tube 32 is inserted inside a synthetic resin flexible conduit tube 31 in which many irregularities in the tubular circumferential direction are repeatedly formed in the tubular longitudinal direction, to produce a flask material 30 for a steel bar insertion hole, the single tube is removed from a precast member which is produced by installing concrete in a flask for a precast member arranged with the flask material for a steel bar insertion hole and the synthetic resin flexible conduit tube is then removed to eliminate the flask material for a steel bar insertion hole, so that a steel bar insertion hole in which irregularities corresponding to the irregularities of the synthetic resin flexible conduit tube are formed on its inner circumferential face is formed at the precast member.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for forming reinforcing bar insertion holes in a precast member, a method for joining precast members in which reinforcing bars are inserted and fixed in the reinforcing bar insertion holes, and a precast member.

When the columns and beams of an RC building are made of precast (PCa) members, the main beam reinforcement at the joints (columns and beams) is often through reinforcement or mechanical joints within the joints. On the other hand, several construction methods have been proposed in which the column-beam joints are also made of PCa, but the only construction methods that have been put into practical use in which all members including the column-beam joints are made of PCa are the LRV method or the SCREAM construction method. There are two construction methods. Looking at the details of these construction methods, in the former case, the main beam reinforcements of the PCa beams that extend half a span in both directions from the joint are grouted to mechanical joints built into the PCa beams to be joined. After PCa beam parts are joined, the column main reinforcement at the lower end of the column PCa (length ≧ joint height + anchoring length) passes through the column main reinforcement penetration hole of the column-beam joint, and the column PCa one layer below (mechanical joint ) The basic mechanism is that the grout is fixed on the grout. Regarding the latter, the column PCa has a shape in which the upper part is integrated with the column-beam joint, and the beam main reinforcement of the beam PCa has a length of (column length + anchorage length) or more, and the column-beam joint is connected from one side. The basic mechanism is that the grout penetrates through the section and is fixed in the female hole (mechanical joint) of the beam PCa on the opposite side. Both of these construction methods aim to change the idea of joining reinforcing bars, which had been conventionally understood until now, by penetrating the entire member and fixing it to the member on the opposite side. This is an unconventional joint method in which the parts are fixed from both sides at the center of the part to achieve integration within the part.

Focusing on methods for making reinforcing bar insertion holes penetrating the interior of the member, there are two known methods: one using a spiral sheathed pipe as the formwork material for the reinforcing bar insertion hole in a PCa member, and the other using a paper void pipe and a thin-walled PVC pipe. However, in the former method of using a spiral sheathed pipe as a formwork material, the sheathed pipe has spiral knots cut into it, so it adheres well to concrete, has high rigidity even if it is thin, and has a high resistance to concrete pressure. It is widely used because the shape of the insertion hole can be maintained even when the insertion hole is activated.

Patent Document 1 discloses that in order to easily provide unevenness in the through hole of the PCa member without using a sheath pipe, a vinyl hose is placed over a single pipe, a rubber string is wound spirally around the vinyl hose, and the PCa member is This jig is used as a construction jig, and this jig is fixed in the position where the through hole is planned to be formed in the formwork, concrete is poured, and after achieving the specified strength, the single pipe, vinyl hose, and rubber string are The jigs are removed in order, and the remains of the removed jigs become through-holes for the main reinforcement, and by forming a spirally extending recess on the inner surface, the through-holes for the main reinforcement can be formed in the PCa member without a sheath tube. Disclosed is a method for manufacturing a PCa member in which the inner surface of the through hole is easily provided with unevenness (FIG. 5).

Japanese Patent Application Publication No. 2018-135686

In the conventional method of using a spiral sheathed pipe, the sheathed pipe of the same shape is simply installed in a predetermined position, but if the grout injection hole is ultimately placed in the middle of the pipe, the joint of the injection hole has a complicated shape. In addition, because the types of pipe diameters are limited, the gap between the pipes and the reinforcing bars becomes relatively large, and there is a possibility that more grout material will be used than necessary. Moreover, since the result is a waste formwork, material for the entire length of the through hole is required. In other words, a spiral sheathed pipe is a disposable formwork, and considering its price and installation time, it cannot be said to be cheap.Also, it is necessary to use a sheathed pipe with a diameter larger than the diameter of the reinforcing bar to be inserted. , there is a high possibility that there will be restrictions on the placement of reinforcing bars at locations where they intersect.

In addition, in the method of using paper void pipes and thin-walled PVC pipes, they can be used as formwork materials as they are, just like sheathed pipes, and can be repurposed by applying a release agent, but in any case, Since the finished surface is exposed, there is a high possibility that the adhesion force of the reinforcing bars will be significantly reduced.

In the method of Patent Document 1, in order to realize a construction method that does not use a sheathed pipe, a vinyl hose is placed over a single pipe, and a jig in which a rubber cord is spirally wound around the vinyl hose is fixed in a formwork. Since a spiral groove is formed using a rubber cord wrapped around the vinyl hose, the groove often does not have a proper shape, and there is a high possibility that the adhesion of the reinforcing bars will be reduced. Furthermore, removing the rubber cord from the precast member is time-consuming and not easy.

It is clear from the component configurations of the LRV construction method and the scrim construction method that the main reinforcement hole is the key to increasing the precast rate using the precast (PCa) construction method. However, structurally, it is necessary to ensure the adhesion of the reinforcing bars within the through-hole, and it is a necessary condition that the grout material forming the interface be injected densely over the entire area within the through-hole. Furthermore, adhesion is expected at the contact surface between the through hole and the grout material, but with void material and PVC pipe, the contact surface is smooth, so there is a high possibility of rupture at the interface, and at least as much adhesion as with the sheath pipe. You can't expect it to hold well.

In view of the problems of the prior art as described above, the present invention provides a material structure that can be removed from molds and used for other purposes by finishing the interface of the reinforcing bar insertion hole with a finish that can be expected to have strong adhesion to the reinforcing bars without using a spiral-shaped sheath pipe. The purpose of the present invention is to provide a method for forming reinforcing bar insertion holes in a precast (PCa) member that can realize cost reduction, a method for joining precast members that inserts reinforcing bars into the reinforcing bar insertion holes, and securely fixes the reinforcing bars, and a precast member. do.

A method for forming reinforcing bar insertion holes in a precast member to achieve the above object is a method of forming reinforcing bar insertion holes in a precast member, comprising:
A step of inserting a single tube into the inside of a synthetic resin flexible electrical conduit tube in which a large number of irregularities in the tube circumferential direction are repeatedly formed in the longitudinal direction of the tube to produce a formwork material for reinforcing bar insertion holes, and a mold for the reinforcing bar insertion holes. a step of placing a frame material in a precast member form; a step of pouring concrete into the precast member form; a step of removing the single pipe from the precast member produced by the concrete pouring; and a step of removing the single pipe from the precast member. a step of removing the reinforcing bar insertion hole formwork material by removing the synthetic resin flexible conduit from the member;
By removing the reinforcing bar insertion hole formwork material, a reinforcing bar insertion hole is formed in the precast member, the inner circumferential surface of which has concavities and convexities corresponding to the concavities and convexities of the synthetic resin flexible conduit.

According to this method for forming reinforcing bar insertion holes in precast members, the reinforcing bar insertion holes are made by inserting a single pipe into the inside of a synthetic resin flexible conduit tube in which a large number of irregularities in the pipe circumferential direction are repeatedly formed in the longitudinal direction of the pipe. The formwork material is placed in the formwork for the precast member, and after concrete pouring, the single tube is removed from the precast member and the synthetic resin flexible conduit is removed. The resulting reinforcing bar insertion hole has a large number of concavities and convexities in the longitudinal direction of the hole, which correspond to the concavities and convexities of the synthetic resin flexible conduit, on its inner peripheral surface. The numerous irregularities on the inner circumferential surface of the reinforcing bar insertion hole are caused by the irregularities of the relatively hard synthetic resin flexible conduit tube, resulting in a clear shape and a high-quality finish. Therefore, by inserting a reinforcing bar into the reinforcing bar insertion hole of this precast member and filling it with a filler, sufficient adhesion force of the filler can be obtained due to the uneven surface formed in the reinforcing bar insertion hole. In this way, sufficient fixing force of the reinforcing bars can be obtained within the reinforcing bar insertion hole without using the conventional spiral sheath pipe, and the reinforcing bars and the precast member can be reliably integrated. In addition, synthetic resin flexible conduit tubes, which are often used in the field of electrical work and are relatively inexpensive commercially available products, are repurposed, eliminating the need for sheathed tubes, which is advantageous in terms of cost without increasing material costs. .

In the method for forming a reinforcing bar insertion hole in a precast member, a cut is made in advance over the entire length of the synthetic resin flexible electrical conduit, and after the single tube is pulled out, the synthetic resin flexible electrical conduit is inserted into the synthetic resin flexible electrical conduit at the cut. By bending it inward and removing it, it can be easily removed from the precast member.

Further, it is preferable that a reinforcing bar cover is placed around the outer periphery of the single tube, if necessary, and then the single tube is inserted inside the synthetic resin flexible conduit. This makes it easier to pull out the single tube.

Further, by making a cut in advance over the entire length of the reinforcing bar cover, and removing the single pipe by bending the reinforcing bar cover inward from the cut, it is easy to remove the reinforcing bar cover.

A method for joining precast members to achieve the above object is to form a first reinforcing bar insertion hole in a first precast member and a second reinforcing bar insertion hole in a second precast member by the above-described method for forming reinforcing bar insertion holes in a precast member. Then, reinforcing bars are inserted into the first and second reinforcing bar insertion holes, and then a filler is filled into the first and second reinforcing bar insertion holes to fix the reinforcing bars, thereby forming the first precast member. The second precast member is joined to the second precast member.

According to this precast member joining method, reinforcing bars are inserted into the first and second reinforcing bar insertion holes formed by the above-described method for forming reinforcing bar insertion holes in a precast member, and then the first reinforcing bar is filled with a filler material. Sufficient adhesive force of the filler can be obtained in the first and second reinforcing bar insertion holes of the first and second precast members. In this way, sufficient fixing force of the reinforcing bars is obtained within the reinforcing bar insertion hole without using the conventional spiral sheath pipe, and the reinforcing bars and the precast member are reliably integrated. It is possible to reliably join the precast member.

A precast member for achieving the above object has reinforcing bar insertion holes formed by the above-described method for forming reinforcing bar insertion holes in a precast member.

According to this precast member, the reinforcing bar insertion hole has a large number of irregularities formed in the longitudinal direction of the hole on its inner peripheral surface, corresponding to the irregularities of the synthetic resin flexible electric conduit. The numerous irregularities on the inner circumferential surface of this reinforcing bar insertion hole are caused by the irregularities of the flexible electrical conduit tube made of hard synthetic resin, resulting in a clear shape and a high-quality finish. When reinforcing bars are inserted into the reinforcing bar insertion holes of this precast member and filled with filler material, sufficient adhesion force can be obtained by the filler material within the reinforcing bar insertion holes, and sufficient anchoring force of the reinforcing bars can be obtained within the reinforcing bar insertion holes. As a result, the reinforcing bars and the precast member can be reliably integrated.

According to the method for forming a reinforcing bar insertion hole in a precast member, the method for joining a precast member, and the precast member of the present invention, the interface of the reinforcing bar insertion hole is finished so that it can be expected to have strong adhesion to the reinforcing bar without using a spiral sheath pipe. In addition, it is possible to reduce costs by making the material composition removable and reusable.In addition, by inserting reinforcing bars into the reinforcing bar insertion holes of precast members, it is possible to securely connect the reinforcing bars and precast members. The precast members can be reliably joined together.

(a) An external view showing the manufacturing process of a formwork material for forming reinforcing bar insertion holes made of a single tube and a synthetic resin flexible conduit according to the present embodiment, and an external view (b) of the formwork material after manufacturing. ) and a side view (c) of the formwork material seen from the end. FIG. 2 is a partial side view (a) and a cross-sectional view (b) taken along the longitudinal direction of the synthetic resin flexible electrical conduit shown in FIG. 1. FIG. It is a side view similar to FIG.1(c) of the formwork material for forming a reinforcing-bar insertion hole comprised by covering a single pipe with a reinforcing-bar cover. It is a sectional side view of the main part of the column-beam joint part which is a precast member in this embodiment. It is a sectional side view of the main part of the beam member which is a precast member in this embodiment. 6 is a sectional view of a main part of a reinforcing bar insertion hole formed in the column-beam joint of FIG. 4 and the beam member of FIG. 5. FIG. It is a flowchart for explaining the process of forming reinforcing bar insertion holes and the process of joining precast members together according to the present embodiment. FIG. 6 is a side sectional view showing a situation in which the main beam reinforcement is inserted into the reinforcing bar insertion hole of the column-beam joint of FIG. 4 and the reinforcing bar insertion hole of the beam member of FIG. 5; This is a photograph of the appearance of a reinforcing bar insertion hole formed in a concrete member in this experimental example.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated using drawings. FIG. 1 is an external view (a) showing the manufacturing process of a formwork material for forming reinforcing bar insertion holes made of a single pipe and a synthetic resin flexible conduit according to the present embodiment, and an appearance of the formwork material after manufacturing. They are figure (b) and a side view (c) which looked at formwork material from an end. FIG. 2 is a partial side view (a) of the synthetic resin flexible electrical conduit shown in FIG. 1, and a cross-sectional view (b) taken along the length of the tube. FIG. 3 is a side view similar to FIG. 1(c) of a formwork material for forming reinforcing bar insertion holes configured by covering a single pipe with a reinforcing bar cover.

As shown in FIGS. 1(a) to 1(c), reinforcing steel can be inserted by inserting a single pipe 32 made of PVC pipe, steel pipe, etc. inside the synthetic resin flexible conduit 31 (see FIG. 2(b)). A formwork material 30 for forming holes is produced. Note that a reinforcing bar or steel bar having the same diameter as the reinforcing bar actually used may be used as the single pipe 32.

As shown in FIGS. 2(a) and 2(b), the synthetic resin flexible electrical conduit 31 has a concave portion 31a formed around the pipe circumferentially, and a convex portion 31b integrally formed around the concave portion 31a. , and a large number of concave portions 31a and convex portions 31b are repeatedly formed in the longitudinal direction of the tube. In addition, the synthetic resin flexible electrical conduit 31 is used by being buried in concrete or exposed so as to pass the electric wire inside, and is widely used in the field of electrical work, and is commercially available as PF pipe or CD pipe. The product is available in a number of inner diameter sizes.

Moreover, the length of the reinforcing bar insertion hole forming formwork material 30 is set according to the length of the reinforcing bar insertion hole in the precast member to be produced. The diameter of the reinforcing bar insertion hole forming formwork material 30 corresponds to the outer diameter of the synthetic resin flexible electrical conduit 31, and is selected from the predetermined size (inner diameter) of the PF pipe/CD pipe according to the reinforcing bar diameter. The outer diameter of the single pipe 32 is selected depending on the diameter of the reinforcing bar inserted into the reinforcing bar insertion hole.

In addition, due to the relationship between the inner diameter of the synthetic resin flexible conduit 31 and the outer diameter of the single tube 32, if necessary, as shown in FIG. By inserting this single tube 32 inside the flexible electrical conduit tube 31 made of synthetic resin, it may be used as a formwork material 30A for forming reinforcing bar insertion holes.

In addition, cuts are made in advance over the entire length of the synthetic resin flexible electrical conduit 31, and when removing the reinforcing bar insertion hole forming formwork 30, the single pipe 32 is pulled out and then the synthetic resin flexible electrical conduit 31 is cut. It is preferable that the electric conduit 31 can be removed by bending it inward from the cut. Also, in the case of FIG. 3, a cut is made in advance over the entire length of the reinforcing bar cover 33, and when demolding the formwork material 30 for forming reinforcing bar insertion holes, the single pipe 32 is pulled out and the reinforcing bar cover 33 is inserted through the cut. It is preferable to bend it inward so that it can be removed.

Next, an example of a precast member for forming reinforcing bar insertion holes using the reinforcing bar insertion hole forming formwork material 30 shown in FIGS. 1 and 2 will be described. FIG. 4 is a sectional side view of a main part of a column-beam joint that is a precast member in this embodiment. FIG. 5 is a side cross-sectional view of a main part of a beam member which is also a precast member. FIG. 6 is a sectional view of a main part of the reinforcing bar insertion hole formed in the column-beam joint of FIG. 4 and the beam member of FIG. 5.

As shown in FIG. 4, the column-beam joint 11 is a precast member including a joint between a column and a beam, and includes a plurality of column main reinforcements 11d and a plurality of intra-column shear reinforcements connected orthogonally to the column main reinforcements 11d. As shown by broken lines, a plurality of reinforcing bar insertion holes 17 into which beam main reinforcing bars will be inserted in a later process are formed as horizontal holes penetrating in the horizontal direction. Note that a plurality of injection pipes 20 for injecting and filling the plurality of reinforcing bar insertion holes 17 with filler are arranged in the column-beam joint 11 .

As shown in FIG. 5, the beam member 12 is a precast member to be joined to the column-beam joint 11 of FIG. As shown by the broken line 5, a plurality of reinforcing bar insertion holes 18 are formed as horizontal holes from the mechanical filling joint 15 to the end of the beam member, into which beam main reinforcements will be inserted in a later process. On one side of the mechanical filling joint 15, a plurality of beam main reinforcements 12a and a plurality of shear reinforcing bars 12b connected orthogonally to the beam main reinforcements 12a etc. are arranged. It is established.

The column-beam joint 11 in Fig. 4 is made by pouring concrete into a predetermined formwork (not shown), but the reinforcing bar insertion holes 17 are made in a predetermined formwork (not shown) in Figs. It is formed by arranging the formwork material 30 for forming reinforcing bar insertion holes No. 2 and removing the mold after pouring concrete. The beam member 12 in FIG. 5 is manufactured by pouring concrete into a predetermined formwork (not shown), and the reinforcing bar insertion holes 18 are formed in the predetermined formwork (not shown) as shown in FIGS. 1 and 2. It is formed by arranging the formwork material 30 for forming reinforcing bar insertion holes and removing the mold after pouring concrete.

As shown in FIG. 6, the recess 31a of the synthetic resin flexible conduit 31 is provided on the inner peripheral surface of the reinforcing bar insertion hole 17 of the column-beam joint 11 in FIG. 4 and the reinforcing bar insertion hole 18 of the beam member 12 in FIG. A large number of corresponding protrusions A that extend around the circumferential direction and recesses B that extend around the circumference that correspond to the protrusions 31b are repeatedly formed in the hole axis direction.

Next, the process of forming reinforcing bar insertion holes in precast members and the process of joining precast members together will be described with reference to FIGS. 1 to 8. FIG. 7 is a flowchart for explaining the process of forming reinforcing bar insertion holes and the process of joining precast members together according to this embodiment. FIG. 8 is a side sectional view showing a state in which the main beam reinforcement is inserted into the reinforcing bar insertion hole of the column-beam joint of FIG. 4 and the reinforcing bar insertion hole of the beam member of FIG. 5.

First, the steps S01 to S16 for forming reinforcing bar insertion holes in a precast member will be explained. In this forming step, as shown in FIG. The formwork material 30A inserted into the mold is used.

As shown in FIGS. 1 to 3, a reinforcing bar cover 33 made of styrene void is placed on a single tube 32 made of steel (S01), and this single tube 32 is inserted inside a flexible electrical conduit 31 made of synthetic resin (S02). , a formwork material 30A for forming reinforcing bar insertion holes is produced (S03).

Next, the reinforcing bar insertion hole forming formwork material 30A is attached to a precast member formwork (not shown) (S04), and the position of the reinforcing bar insertion hole formed in the precast member is adjusted (S05). Next, concrete is poured into the precast member formwork (S06), and after a predetermined period of time, the precast member formwork is removed (S07) to expose the precast member. Note that such a precast member may be the column-beam joint 11 in FIG. 4 or the beam member 12 in FIG. 5.

Next, demolding of the reinforcing bar insertion hole forming formwork material 30A is prepared (S08). That is, the single tube 32 is exposed on a predetermined surface of the precast member (S09), and the single tube 32 is pulled out and removed (S10). Next, the styrene void (reinforcing bar cover 33) is exposed (S11), and the styrene void is removed (S12). At this time, since the styrene void is cut along its entire length, the styrene void can be easily bent inward and removed, making it easy to remove.

Next, the synthetic resin flexible electrical conduit 31 is exposed (S13), and the synthetic resin flexible electrical conduit 31 is removed, thereby completing demolding of the reinforcing bar insertion hole forming formwork material 30A (S14). . At this time, since the synthetic resin flexible electrical conduit 31 is cut along its entire length, the synthetic resin flexible electrical conduit 31 can be easily bent inward and removed, and easily removed from the precast member. Can be removed.

Next, by demolding the formwork material 30A for forming reinforcing bar insertion holes, reinforcing bar insertion holes 17 and 18 are exposed in, for example, the column-beam joint 11 in FIG. 4 and the beam member 12 in FIG. 5 (S15), and the reinforcing bar insertion holes The finished shapes of 17 and 18 are confirmed (S16).

As described above, the reinforcing bar insertion holes 17 and 18 can be formed in the precast member of the column-beam joint 11 in FIG. 4 and the beam member 12 in FIG. As shown in FIG. 6, a convex part A that goes around the circumferential direction corresponding to the concave part 31a of the synthetic resin flexible conduit 31 and a concave part B that goes around the circumferential direction that corresponds to the convex part 31b are repeated in the hole axis direction. Many are formed. The convex portion A and the concave portion B have a clear shape and a high-quality finish due to the concave portion 31a and the convex portion 31b of the flexible electrical conduit 31 made of relatively hard synthetic resin. Therefore, when the reinforcing bars are inserted into the reinforcing bar insertion holes and filled with the filler, sufficient adhesive force of the filler can be obtained within the reinforcing bar insertion holes. In this way, sufficient fixing force of the reinforcing bars can be obtained within the reinforcing bar insertion holes without using the conventional spiral sheath pipe, and the reinforcing bars and the precast member can be reliably integrated. In addition, synthetic resin flexible electrical conduit, which is a relatively inexpensive commercially available product that is often used in the field of electrical work, is used, eliminating the need for sheathed pipes, which is advantageous in terms of cost without increasing material costs. .

In addition, as in Patent Document 1, the inner circumferential surface of the reinforcing bar insertion hole is formed by a formwork material in which a vinyl hose is wrapped around a single pipe and a rubber string is wound spirally around the vinyl hose. The shape of the groove is formed by a soft vinyl hose and a rubber cord, which tends to result in an unclear groove shape and insufficient quality. Since the conduit 31 is used, and the numerous recesses 31a and protrusions 31b on its outer circumferential surface are not easily deformed by the poured concrete, a high-quality reinforcing bar insertion hole with a clear groove shape on the inner circumferential surface can be formed. . Therefore, it is possible to obtain sufficient adhesion force by the filler within the reinforcing bar insertion hole. Further, in Patent Document 1, a troublesome step of spirally wrapping a rubber cord around the vinyl hose is required, but in the forming method of the present embodiment, the single tube 32 is attached to the inside of the synthetic resin flexible electrical conduit 31. Formwork material can be created by simply inserting it into the mold, making it a simple process.

Next, to explain the joining steps S17 to S19 between precast members, as shown in FIG. 14 is prepared (S17), and with the beam member 12 supported and positioned with supporting material etc. in the column-beam joint 11, the reinforcing bars 14 are inserted from the reinforcing bar insertion hole 17 of the column-beam joint 11, and the beam member 12 is inserted into the beam member 12. The reinforcing bar 14 is inserted into the reinforcing bar insertion hole 18, and the tip of the reinforcing bar 14 is inserted into the mechanical filling joint 15 in the beam member 12 and fixed at an appropriate position (S18).

Next, by injecting a filler such as grout into the reinforcing bar insertion hole 17 through the injection pipe 20 previously provided in the column-beam joint 11, the reinforcing bar insertion hole 17 and the reinforcing bar 14 are formed as shown in FIG. The hole filling space S is filled with a filler material (S19). By injecting the filler, the filler is filled from the reinforcing bar insertion hole 17 to the in-hole filling space S between the reinforcing bar insertion hole 18 of the beam member 12 and the reinforcing bar 14 and the mechanical filling joint 15.

As described above, by filling the filling space S (FIG. 6) in the reinforcing bar insertion hole 17 of the column-beam joint 11 and the reinforcing bar insertion hole 18 of the beam member 12 with the filler material, the column-beam joint 11 Sufficient adhesion force can be obtained after the filler hardens in the reinforcing bar insertion holes 17 and the reinforcing bar insertion holes 18 of the beam member 12. In this way, sufficient fixing force of the reinforcing bars 14 can be obtained within the reinforcing bar insertion holes 17 and 18 without using the conventional spiral-shaped sheath pipe, and the reinforcing bars 14, column-beam joints 11, and beam members 12 can be securely connected. By integrating them, the column-beam joint 11 and the beam member 12 can be reliably joined.

In addition, in FIG. 8, when the reinforcing bars 14 are inserted into the reinforcing bar insertion holes 17 of the column-beam joint 11 and the reinforcing bar insertion holes 18 of the beam member 12, they protrude to the right side of the column-beam joint 11 in FIG. Another beam member (not shown) is arranged on the right side of the joint 11, and the protruding portion of the reinforcing bar 14 is inserted into a reinforcing bar insertion hole similar to the reinforcing bar insertion hole 18, and is fixed by a filler. can.

(Experiment example)
Next, an experimental example in which reinforcing bar insertion holes were formed in a concrete member using the reinforcing bar insertion hole forming method of this embodiment will be described. In this experiment example, a formwork material for forming reinforcing bar insertion holes similar to that shown in Fig. 3 was prepared with a synthetic resin flexible conduit tube inner diameter of 53 mm, styrene void T = 5 mm, and a single tube outer diameter of 42.7 mm, and placed in the formwork. After fixing, concrete was poured, the formwork was removed to expose the concrete member, and the formwork material for forming reinforcing bar insertion holes was removed from the concrete member. Figure 9 shows a photograph of the appearance of a reinforcing bar insertion hole formed in a concrete member. It can be seen from FIG. 9 that the inner circumferential surface of the reinforcing bar insertion hole has a clear uneven shape that corresponds to the unevenness on the outer periphery of the synthetic resin flexible conduit tube, and has a high-quality finish.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the technical idea of the present invention. For example, in FIGS. 4 and 5, a column-beam joint or a beam member is used as an example of a precast member, but the present invention is not limited thereto, and can of course be applied to reinforcing bar insertion holes of other precast members.

In addition, in the reinforcing bar insertion hole forming steps S01 to S16 in FIG. 7, the formwork material 30A in FIG. 3 was used, but the single pipe 32 in FIG. Of course, it is also possible to use the formwork material 30 inserted inside, and in this case, steps S01 and S12 in FIG. 7 are omitted.

According to the present invention, the interface of the reinforcing bar insertion hole of a precast member can be finished with a finish that can be expected to have strong adhesion to the reinforcing bar without using a spiral sheath pipe, and the material composition can be removed and reused. As a result, cost reduction can be achieved. The reinforcing bars can be inserted into the reinforcing bar insertion holes of the precast members to reliably integrate the reinforcing bars and the precast members, and the precast members can be reliably joined to each other, thereby improving quality and reducing costs in various construction works including such joining processes. be able to.

11 Column beam joint (precast member)
12 Beam member (precast member)
14 Reinforcing bars 17, 18 Reinforcing bar insertion holes 30, 30A Formwork material for reinforcing bar insertion holes 31 Synthetic resin flexible electrical conduit 31a Concave portion 31b of synthetic resin flexible electrical conduit Convex portion 32 of synthetic resin flexible electrical conduit 33 Reinforcing bar cover A Convex portion B on the inner circumferential surface of the reinforcing bar insertion hole Recessed portion S on the inner circumferential surface of the reinforcing bar insertion hole Hole filling space

The present invention relates to a method of forming reinforcing bar insertion holes in a precast member, a method of joining precast members in which reinforcing bars are inserted and fixed in the reinforcing bar insertion holes, and a method of manufacturing a precast member.

In view of the problems of the prior art as described above, the present invention provides a material structure that can be removed from molds and used for other purposes by finishing the interface of the reinforcing bar insertion hole with a finish that can be expected to have strong adhesion to the reinforcing bars without using a spiral-shaped sheath pipe. To provide a method for forming a reinforcing bar insertion hole in a precast (PCa) member that can realize cost reduction, a method for joining a precast member in which reinforcing bars are inserted into the reinforcing bar insertion hole and securely fixed therein, and a method for manufacturing a precast member. With the goal.

A method for forming reinforcing bar insertion holes in a precast member to achieve the above object is a method of forming reinforcing bar insertion holes in a precast member, comprising:
A process for arranging a reinforcing bar cover around the outer periphery of the single pipe, and inserting the single pipe into the inside of a synthetic resin flexible electrical conduit tube in which a large number of irregularities in the pipe circumferential direction are repeatedly formed in the longitudinal direction of the pipe to form a reinforcing bar insertion hole mold. A step of producing a frame material, a step of arranging the formwork material for the reinforcing bar insertion hole in a formwork for a precast member, a step of pouring concrete into the formwork for a precast member, and a step of producing the concrete by the concrete pouring. removing the single pipe from the precast member; and removing the reinforcing bar insertion hole formwork material by removing the synthetic resin flexible conduit from the precast member,
By removing the reinforcing bar insertion hole formwork material, a reinforcing bar insertion hole is formed in the precast member, the inner circumferential surface of which has concavities and convexities corresponding to the concavities and convexities of the synthetic resin flexible conduit.

According to this method of forming a reinforcing bar insertion hole in a precast member, a reinforcing bar cover is arranged on the outer periphery of a single tube inside a synthetic resin flexible conduit tube in which a large number of irregularities in the circumferential direction are repeatedly formed in the longitudinal direction of the tube. The formwork material for the reinforcing bar insertion hole prepared by inserting the above is placed in the formwork for the precast member, and after concrete pouring, the single tube is removed from the precast member and the synthetic resin flexible conduit is removed to create the formwork for the reinforcing bar insertion hole. A reinforcing bar insertion hole formed in a precast member after demolding the material has a large number of concavities and convexities in the longitudinal direction of the hole, which correspond to the concavities and convexities of the synthetic resin flexible conduit, on the inner circumferential surface of the hole. The numerous irregularities on the inner circumferential surface of the reinforcing bar insertion hole are caused by the irregularities of the relatively hard synthetic resin flexible conduit tube, resulting in a clear shape and a high-quality finish. Therefore, by inserting a reinforcing bar into the reinforcing bar insertion hole of this precast member and filling it with a filler, sufficient adhesion force of the filler can be obtained due to the uneven surface formed in the reinforcing bar insertion hole. In this way, sufficient fixing force of the reinforcing bars can be obtained within the reinforcing bar insertion holes without using the conventional spiral sheath pipe, and the reinforcing bars and the precast member can be reliably integrated. In addition, synthetic resin flexible electrical conduit, which is a relatively inexpensive commercially available product that is often used in the field of electrical work, is used, eliminating the need for sheathed pipes, which is advantageous in terms of cost without increasing material costs. .

A method for manufacturing a precast member to achieve the above object is to form reinforcing bar insertion holes using the above-described method for forming reinforcing bar insertion holes in a precast member.

According to the precast member manufactured by this manufacturing method , the reinforcing bar insertion hole has many irregularities in the longitudinal direction of the hole corresponding to the irregularities of the synthetic resin flexible conduit tube on the inner peripheral surface thereof. There is. The numerous irregularities on the inner circumferential surface of this reinforcing bar insertion hole are caused by the irregularities of the flexible electrical conduit tube made of hard synthetic resin, resulting in a clear shape and a high-quality finish. When reinforcing bars are inserted into the reinforcing bar insertion holes of this precast member and filled with filler material, sufficient adhesion force can be obtained by the filler material within the reinforcing bar insertion holes, and sufficient anchoring force of the reinforcing bars can be obtained within the reinforcing bar insertion holes. As a result, the reinforcing bars and the precast member can be reliably integrated.

According to the method of forming a reinforcing bar insertion hole in a precast member, the method of joining a precast member, and the method of manufacturing a precast member of the present invention, the interface of the reinforcing bar insertion hole can be bonded to the reinforcing bar without using a spiral sheath pipe. It is possible to achieve a desired finish and to create a material composition that can be demolded and reused, making it possible to reduce costs.In addition, the reinforcing bars can be inserted into the reinforcing bar insertion holes of the precast parts, and the reinforcing bars and the precast parts can be separated. can be reliably integrated, and precast members can be reliably joined together.

Claims (6)

A method for forming reinforcing bar insertion holes in a precast member, the method comprising:
A step of inserting a single tube inside a flexible electrical conduit tube made of synthetic resin in which a large number of irregularities in the circumferential direction are repeatedly formed in the longitudinal direction of the tube to create a formwork material for a reinforcing bar insertion hole;
arranging the reinforcing bar insertion hole formwork material in a precast member formwork;
a step of pouring concrete into the formwork for the precast member;
a step of removing the single pipe from the precast member produced by the concrete pouring;
a step of removing the reinforcing bar insertion hole formwork material by removing the synthetic resin flexible conduit from the precast member;
A reinforcing bar insertion hole of the precast member is formed in the precast member, the reinforcing bar insertion hole having an inner circumference formed with unevenness corresponding to the unevenness of the synthetic resin flexible conduit by removing the reinforcing bar insertion hole formwork material. Formation method. Claim 1: A cut is made in advance over the entire length of the synthetic resin flexible electrical conduit, and after the single tube is removed, the synthetic resin flexible electrical conduit can be bent inward from the cut and removed. A method for forming reinforcing bar insertion holes in a precast member as described in . 3. The method for forming a reinforcing bar insertion hole in a precast member according to claim 1, wherein a reinforcing bar cover is placed around the outer periphery of the single tube, and then the single tube is inserted into the inside of the synthetic resin flexible electrical conduit. A reinforcing bar insertion hole of a precast member according to claim 3, wherein cuts are made in advance over the entire length of the reinforcing bar cover, and after the single pipe is pulled out, the reinforcing bar cover can be removed by bending inward from the cuts. Formation method. The first reinforcing bar insertion hole of the first precast member and the second reinforcing bar insertion hole of the second precast member are respectively formed by the method for forming reinforcing bar insertion holes of a precast member according to any one of claims 1 to 4, and and the first precast member and the second precast member by inserting reinforcing bars into the second reinforcing bar insertion holes, and then filling the first and second reinforcing bar insertion holes with a filler material to fix the reinforcing bars. A method for joining precast members. A precast member having a reinforcing bar insertion hole formed by the method for forming a reinforcing bar insertion hole in a precast member according to any one of claims 1 to 4.

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