JP2023170197A - Precast beam joint structure - Google Patents

Abstract

To narrow the width of a precast beam member in the precast beam member having a spring-out part spring-out from the outside surface of an outdoor side.SOLUTION: A precast beam joint structure includes: a first precast beam member 10 having a column-beam joint part 12, a beam part 20 extending from the column-beam joint part 12, a balcony 24 projecting from an outside surface 20A of the outdoor side of the beam part 20, and a mechanical joint 16 embedded in the column-beam joint part 12 and having one end side for opening an indoor side inner surface 12B of the column-beam joint part 12; and a second precast beam member 50 having a beam main reinforcement 52 connected to one end side of the mechanical joint 16.SELECTED DRAWING: Figure 2

Description

The present invention relates to a precast beam joint structure.

A joint structure between a precast column and beam joint part and a precast beam member is known (see, for example, Patent Documents 1 and 2).

JP2020-097846A JP2022-018838A

By the way, it is conceivable to integrally precast a balcony on the outside surface of the precast beam member on the outdoor side. In this case, compared to the case where the beam member and the balcony are precast separately, the number of times the precast beam member is lifted, the number of installation operations, etc. are reduced, and workability is improved.

However, in general, a beam main reinforcement that protrudes toward the indoor side is provided at the column-beam joint portion of a precast beam member, and the beam main reinforcements of other precast beam members are connected to this main beam reinforcement.

Therefore, if a projecting part such as a balcony is integrally precast on the outside surface of a precast beam member on the outdoor side, the width of the precast beam member (member width) will become wider, and for example, there is a possibility that it will exceed the limit for mounting on a truck. be.

The present invention takes the above-mentioned facts into account, and aims to reduce the width of a precast beam member having a protruding portion that protrudes from the outside surface on the outdoor side.

The precast beam joint structure according to claim 1 includes: a column-beam joint part, a beam part extending from the column-beam joint part, and a projecting part that springs out from the outside surface of the beam part on the outdoor side. a precast beam member having a mechanical joint that is buried in the column-beam joint and one end side of which opens an interior surface on the indoor side of the column-beam joint; and a beam main reinforcement is on the one end side of the mechanical joint. A beam member connected to the.

According to the precast beam joining structure according to the first aspect, the precast beam member has a column-beam joint part, a beam part, a protruding part, and a mechanical joint. The beam portion extends from the column and beam joint portion. Further, the protruding portion protrudes from the outer surface of the beam portion on the outdoor side.

Here, mechanical joints are embedded in the column and beam joints. One end of the mechanical joint opens on the interior side of the column-beam joint on the indoor side. The main beam reinforcement of the beam member is connected to one end side of this mechanical joint.

In this way, in the present invention, by embedding a mechanical joint in the column-beam joint, the width of the precast beam member (member width ) can be narrowed.

The precast beam joint structure according to claim 2 is the precast beam joint structure according to claim 1, in which the main beam reinforcement protrudes from the beam end surface of the beam member and is connected to the inner surface of the column-beam joint part. A cast-in-place concrete portion is provided between the beam member and the beam end surface.

According to the precast beam joint structure according to the second aspect, the cast-in-place concrete portion is provided between the inner surface of the column-beam joint portion and the beam end surface of the beam member.

Here, if the distance between the inner surface of the column-beam joint and the beam end face of the beam member is narrow, the main beam reinforcement of the beam member is inserted into the mechanical joint buried in the column-beam joint. It becomes difficult to fill mechanical joints with fillers such as grout and mortar.

In contrast, in the present invention, as described above, a cast-in-place concrete portion is provided between the inner surface of the column and beam joint portion and the beam end surface of the beam member. Therefore, in the present invention, compared to a structure in which a filler such as grout is filled between the inner surface of the column-beam joint and the beam end surface of the beam member, the inner surface of the column-beam joint and the beam end surface of the beam member are The distance from the beam end face can be increased.

Therefore, with the main beam reinforcement of the beam member inserted into the mechanical joint buried in the column-beam joint, it becomes easier to fill the mechanical joint with filler such as grout, improving workability.

The precast beam joint structure according to claim 3 is the precast beam joint structure according to claim 1 or 2, in which the column and beam joint part includes a machine connected to the other end side of the mechanical joint. A type fixing body is embedded.

According to the precast beam joining structure according to the third aspect, a mechanical fixing body is embedded in the column and beam joint portion. The mechanical fixing body is connected to the other end of the mechanical joint. As a result, the length of the mechanical joint can be shortened, and the fixing force of the mechanical joint to the column-beam joint can be increased.

As explained above, according to the present invention, the width of the precast beam member can be narrowed in the precast beam member having the protruding portion that protrudes from the outside surface on the outdoor side.

It is a top view which shows the 1st precast beam member and the 2nd precast beam member to which the precast beam joint structure was applied to one embodiment. 2 is a sectional view taken along line 2-2 in FIG. 1. FIG. FIG. 3 is an exploded longitudinal sectional view of the first precast beam member and the second precast beam member shown in FIG. 2; FIG. 3 is a longitudinal cross-sectional view of the column-beam joint portion for explaining a method of filling a mechanical joint buried in the column-beam joint portion with a filler; (A) is a sectional view taken along line 5A-5A in FIG. 4, and (B) is a sectional view showing a state in which the binding band is removed from the ring-shaped formwork shown in FIG. 5(A).

Hereinafter, a precast beam joint structure according to an embodiment will be described with reference to the drawings.

(Precast beam joint structure)
FIG. 1 shows a first precast beam member 10 and a second precast beam member 50 to which a precast beam joining structure is applied in this embodiment. The first precast beam member 10 and the second precast beam member 50 are arranged to intersect (approximately orthogonally) with each other in plan view.

(First precast beam member)
The first precast beam member 10 is made of precast concrete. This first precast beam member 10 has a column-beam joint part 12, two beam parts 20, and a balcony 24. The column-beam joint portion 12, the two beam portions 20, and the balcony 24 are integrally formed (precast) in a factory or the like. Note that the balcony 24 is an example of a protruding portion. Note that the first precast beam member 10 is an example of a precast beam member.

(Column and beam joint section)
The column-beam joint portion 12 is formed into a rectangular shape when viewed from above. As shown in FIG. 2, the column-beam joint part 12 is arranged between the lower precast column member 30 and the upper precast column member 40, and the lower precast column member 30 and the upper precast column member It is joined with 40. This column-beam joint portion 12 constitutes an outer peripheral column (side column) of the structure, together with the lower precast column member 30 and the upper precast column member 40.

The column-beam joint portion 12 is placed on the upper surface of the lower precast column member 30. A plurality of sheath pipes 14 are buried in the outer peripheral portion of the column-beam joint portion 12. The plurality of sheath pipes 14 are arranged at intervals in the circumferential direction of the column-beam joint part 12. Further, the plurality of sheath pipes 14 are formed in a cylindrical shape, and are buried in the column-beam joint portion 12 along the vertical direction. These sheath pipes 14 form a plurality of through holes that vertically penetrate the column-beam joint section 12 .

The lower precast column member 30 and the upper precast column member 40 are made of precast concrete. Further, the lower precast column member 30 and the upper precast column member 40 are formed into a prismatic shape. These lower precast column member 30, upper precast column member 40, and column-beam joint portion 12 have substantially the same outer shape in plan view.

A plurality of column main reinforcements 32 and shear reinforcing bars (not shown) are buried in the outer peripheral portion of the lower precast column member 30. The upper end portions of the plurality of column main reinforcements 32 extend upward from the upper surface of the lower precast column member 30. These main column reinforcements 32 vertically penetrate the plurality of sheath pipes 14 buried in the column and beam joints 12 and extend upward from the upper surface of the column and beam joints 12 . Note that the sheath pipe 14 is filled with a filler such as grout.

The upper precast column member 40 is placed on the upper surface of the column-beam joint part 12. A plurality of column main reinforcements 42 and shear reinforcing bars (not shown) are buried in the outer peripheral portion of the upper precast column member 40. Further, a plurality of mechanical joints 44 are embedded in the outer peripheral portion of the lower end portion of the upper precast column member 40.

The lower end portions of the plurality of column main reinforcements 42 are inserted into the upper end side of the plurality of mechanical joints 44 . On the other hand, the plurality of column main reinforcements 32 of the lower precast column member 30 are inserted into the lower end sides of the plurality of mechanical joints 44, respectively. Each mechanical joint 44 is filled with a filler such as grout. Thereby, the main column reinforcement 32 of the lower precast column member 30 and the main column reinforcement 42 of the upper precast column member 40 are connected via the mechanical joint 44 .

Note that the joints between the column and beam joints 12, the lower precast column member 30, and the upper precast column member 40 are filled with a filler such as grout or mortar.

In addition, in this embodiment, the main column reinforcement 32 protruding from the upper surface of the lower precast column member 30 vertically penetrates the column and beam joint part 12 of the first precast beam member 10, and the lower end of the upper precast column member 40 It is connected to a mechanical joint 44 embedded in the section. However, the main column reinforcement 42 protruding from the lower surface of the upper precast column member 40 vertically penetrates the column-beam joint part 12 of the first precast beam member 10 and is buried in the upper end of the lower precast column member 30. It may also be connected to a mechanical joint.

(beam)
As shown in FIG. 1, the two beam parts 20 extend outward from both side surfaces of the column-beam joint part 12. A plurality of beam main reinforcements 22 and shear reinforcing bars (not shown) are embedded in each beam portion 20. The plurality of beam main reinforcements 22 extend from the beam end surface of the beam portion 20. These beam main reinforcements 22 are connected to beam main reinforcements of a concrete beam (not shown).

(balcony)
A balcony 24 is provided on the outdoor side of the column-beam joint section 12 and the two beam sections 20. The balcony 24 is provided across the two beam parts 20, and protrudes from the outside surfaces 12A and 20A of the column-beam joint part 12 and the two beam parts 20 on the outdoor side to the outdoor side. Furthermore, a drainage groove 26 is formed on the top surface of the tip of the balcony 24. Note that the drain groove 26 can be omitted.

(Second precast beam member)
As shown in FIG. 2, the second precast beam member 50 is made of precast concrete. Further, the second precast beam member 50 is disposed on the indoor side of the column-beam joint portion 12 of the first precast beam member 10, and is constructed between the column-beam joint portion 12 and a column (not shown). Note that the second precast beam member 50 is an example of a beam member.

A plurality of beam main reinforcements 52 and a plurality of shear reinforcing bars 54 are embedded in the second precast beam member 50 . The plurality of beam main reinforcements 52 protrude from the beam end surface 50T of the second precast beam member 50. These beam main reinforcements 52 are joined to the column-beam joint portion 12 of the first precast beam member 10.

Specifically, a plurality of mechanical joints 16 are embedded in the column-beam joint portion 12. The plurality of mechanical joints 16 are embedded in the indoor side of the first precast beam member 10 along the width direction (arrow W direction) of the first precast beam member 10.

One end side of the plurality of mechanical joints 16 opens the interior side surface 12B of the column-beam joint section 12 on the indoor side. The main beam reinforcement 52 of the first precast beam member 10 is inserted into one end side of these mechanical joints 16 . Further, one end portion of reinforcing bars 17 is inserted into the other end side of the plurality of mechanical joints 16, respectively. Each mechanical joint 16 is filled with a filler (not shown) such as grout. Thereby, the beam main reinforcement 52 and the reinforcing reinforcement 17 are connected via the mechanical joint 16.

Furthermore, a mechanical fixing body 18 is attached to the other end of the reinforcing bar 17 . This mechanical fixing body 18 increases the fixing force of the mechanical joint 16 to the column-beam joint portion 12.

Note that the reinforcing bars 17 and the mechanical fixing body 18 may be provided as necessary, and may be omitted as appropriate. Further, the number and arrangement of mechanical joints 16 can be changed as appropriate depending on the number and arrangement of beam main reinforcements 52.

The beam end surface 50T of the second precast beam member 50 is spaced apart from the inner surface 12B of the column-beam joint portion 12. Cast-in-place concrete is placed in the placement space between the beam end surface 50T of the second precast beam member 50 and the inner surface 12B of the column-beam joint 12. As a result, a cast-in-place concrete portion 56 is provided between the beam end surface 50T of the second precast beam member 50 and the inner surface 12B of the column-beam joint portion 12. Note that shear reinforcing bars 54 are buried in the cast-in-place concrete portion 56.

(Construction method of precast beam joint structure)
Next, an example of a construction method for the precast beam joint structure according to the present embodiment will be described.

FIG. 3 shows a first precast beam member 10 in which a column and beam joint portion 12 is joined to a lower precast column member 30 and an upper precast column member 40. From this state, the second precast beam member 50 is lifted by a lifting machine or the like (not shown), and the beam end surface 50T of the second precast beam member 50 is made to face the inner surface 12B of the column-beam joint portion 12.

In addition, a ring-shaped formwork 70 is attached to each of the plurality of beam main reinforcements 52 protruding from the beam end surface 50T of the second precast beam member 50, and a plurality of shear reinforcing bars 54 are placed close to the beam end surface 50T side. It's hooked.

As shown in FIG. 5(B), the ring-shaped formwork 70 is formed in a ring shape. A through hole 72 into which the main beam reinforcement 52 is inserted is formed in the center of the ring-shaped formwork 70 . Furthermore, a slit 74 reaching the through hole 72 is formed in the peripheral surface 70S of the ring-shaped formwork 70. This slit 74 allows the ring-shaped formwork 70 to be divided.

Next, as shown by the arrow X in FIG. 52 are respectively inserted into a plurality of mechanical joints 16 buried in the column-beam joint section 12.

Next, as shown in FIG. 4, the ring-shaped formwork 70 is slid along the main beam reinforcement 52 and brought into contact with one end of the mechanical joint 16. Next, as shown in FIG. 5(A), the binding band 80 wound around the circumferential surface 70S of the ring-shaped formwork 70 is tightened to close the slit 74 of the ring-shaped formwork 70. Thereby, the ring-shaped formwork 70 closes the opening 16A (see FIG. 4) at one end of the mechanical joint 16.

Next, as shown in FIG. 4, a fixture 90 such as a pie rack is attached to the beam main reinforcement 52, and the ring-shaped formwork 70 is sandwiched between the fixture 90 and the mechanical joint 16. In this state, the bolt 92 attached to the fixture 90 is tightened to fix the fixture 90 to the beam main reinforcement 52. Thereby, the ring-shaped formwork 70 is held between the mechanical joint 16 and the fixture 90.

Next, the inside of the mechanical joint 16 is filled with a filler G such as grout through the injection pipe 60 connected to one end of the mechanical joint 16 . At this time, it is confirmed that the inside of the mechanical joint 16 has been filled with the filler G by discharging the filler G from the discharge pipe 62 connected to the other end of the mechanical joint 16. Note that illustration of the injection pipe 60 and the discharge pipe 62 is omitted in FIGS. 2 and 3.

Next, after the filler G has hardened, the bolts 92 attached to the fixture 90 are loosened, and the fixture 90 is removed from the beam main reinforcement 52. Further, as shown in FIG. 5(B), the binding band 80 is removed from the ring-shaped formwork 70. Then, by dividing the ring-shaped formwork 70 along the slits 74, the ring-shaped formwork 70 is removed from the beam main reinforcement 52.

Next, as shown in FIG. 3, a plurality of shear reinforcing bars 54 are arranged at a predetermined pitch toward the beam end surface 50T side of the second precast beam member 50. Further, a conventional formwork is temporarily installed around the casting space between the beam end surface 50T of the second precast beam member 50 and the inner surface 12B of the column-beam joint part 12.

In this state, cast-in-place concrete is placed between the beam end surface 50T of the second precast beam member 50 and the inner surface 12B of the column-beam joint part 12 (placement space), thereby forming the cast-in-place concrete part 56. . Thereby, the column-beam joint portion 12 and one end portion of the second precast beam member 50 are joined. After that, the conventional formwork will be removed.

(effect)
Next, the operation of this embodiment will be explained.

As shown in FIG. 2, according to this embodiment, the first precast beam member 10 has a column-beam joint part 12, two beam parts 20, a balcony 24, and a mechanical joint 16. The two beam portions 20 extend from the column-beam joint portion 12 to both sides. Moreover, the balcony 24 is provided across the two beam parts 20 and protrudes outward from the outer surface 12A of the beam parts 20 and the column-beam joint part 12.

Here, a mechanical joint 16 is embedded in the column-beam joint portion 12. One end of the mechanical joint 16 opens to the interior side surface 12B of the column-beam joint section 12 on the indoor side. A beam main reinforcement 52 protruding from the beam end surface 50T of the second precast beam member 50 is connected to one end side of the mechanical joint 16.

In this embodiment, the mechanical joint 16 is buried in the column-beam joint part 12 of the first precast beam member 10, so that the beam main reinforcement 52 protrudes from the inner surface 12B of the column-beam joint part 12. Compared to this, the width (member width) of the first precast beam member 10 can be made narrower.

Further, a mechanical fixing body 18 is embedded in the column-beam joint portion 12 of the first precast beam member 10. The mechanical fixing body 18 is connected to the other end of the mechanical joint 16 via reinforcing bars 17. Thereby, the length of the mechanical joint 16 can be shortened, and the fixing force of the mechanical joint 16 to the column-beam joint part 12 can be increased.

Furthermore, in the present embodiment, a cast-in-place concrete portion 56 is provided between the inner surface 12B of the column-beam joint portion 12 of the first precast beam member 10 and the beam end surface 50T of the second precast beam member 50. There is.

Here, if the distance between the inner surface 12B of the column-beam joint part 12 of the first precast beam member 10 and the beam end face 50T of the second precast beam member 50 is narrow, the mechanical When the main beam reinforcement 52 of the second precast beam member 50 is inserted into the joint 16, it becomes difficult to fill the mechanical joint 16 with the filler G.

On the other hand, in this embodiment, as described above, there is no space between the inner surface 12B of the column-beam joint part 12 of the first precast beam member 10 and the beam end surface 50T of the second precast beam member 50. A poured concrete portion 56 is provided. Therefore, when filling a filler such as grout between the inner surface 12B of the column and beam joint section 12 and the beam end surface 50T of the second precast beam member 50, the inner surface 12B of the column and beam joint section 12 and the The distance between the second precast beam member 50 and the beam end surface 50T can be increased.

Therefore, with the beam main reinforcement 52 of the second precast beam member 50 inserted into the mechanical joint 16 buried in the column-beam joint 12, it becomes easier to fill the mechanical joint 16 with the filler G. Improves workability.

Further, as shown in FIG. 4, in this embodiment, when filling the mechanical joint 16 with the filler G, one end side of the mechanical joint 16 is The opening 16A is closed. Thereby, leakage of the filler G from the opening 16A at one end of the mechanical joint 16 can be suppressed.

Furthermore, as shown in FIG. 5(B), a slit 74 is formed in the ring-shaped formwork 70. As a result, after filling the mechanical joint 16 with the filler G, the binding band 80 is loosened and the ring-shaped formwork 70 is divided along the slits 74, so that the beam main reinforcement 52 can easily separate the ring-shaped formwork 70. Can be removed. Therefore, workability is improved.

(Modified example)
Next, a modification of the above embodiment will be described.

In the embodiment described above, the balcony 24 spans the two beam parts 20 of the first precast beam member 10. However, a balcony 24 can be provided on at least one beam 20. Moreover, the balcony 24 can also be provided in a part of the first precast beam member 10 in the longitudinal direction.

Further, in the above embodiment, the projecting portion is the balcony 24. However, the projecting portion is not limited to the balcony 24, and may be, for example, a projecting slab (cantilevered slab), an eave, or the like.

Moreover, in the embodiment described above, the first precast beam member 10 is provided with two beam parts 20. However, the first precast beam member 10 can be provided with at least one beam section 20 .

Further, in the embodiment described above, when filling the mechanical joint 16 with the filler G, the opening 16A of the mechanical joint 16 is temporarily closed by the ring-shaped formwork 70. However, the opening 16A of the mechanical joint 16 may be closed not only by the ring-shaped formwork 70 but also by other methods. For example, the opening 16A of the mechanical joint 16 may be closed with a formwork (saved formwork) or the like, and the formwork may be buried (filled) in the cast-in-place concrete portion 56.

Further, in the above embodiment, the cast-in-place concrete portion 56 is provided between the inner surface 12B of the column-beam joint portion 12 of the first precast beam member 10 and the beam end surface 50T of the second precast beam member 50. There is. However, it is possible to reduce the distance between the inner surface 12B of the column-beam joint part 12 of the first precast beam member 10 and the beam end surface 50T of the second precast beam member 50, fill it with a filler such as grout, and join them. is also possible.

Further, in the above embodiment, the beam member joined to the column-beam joint portion 12 of the first precast beam member 10 is the second precast beam member 50 made of precast concrete. However, the beam member joined to the column-beam joint part 12 of the first precast beam member 10 is not limited to precast concrete construction, and may be constructed of cast-in-place concrete or the like.

Further, in the embodiment described above, the upper precast column member 40 is joined to the column and beam joint portion 12 of the first precast beam member 10. However, the upper precast column member 40 can be omitted as appropriate.

Further, in the above embodiment, the columns joined to the column-beam joint portion 12 of the first precast beam member 10 are the lower precast column member 30 and the upper precast column member 40. However, the column to be joined to the column-beam joint part 12 of the first precast beam member 10 is not limited to precast concrete construction, and may be made of cast-in-place concrete or the like.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and the embodiment and various modifications may be used in combination as appropriate, and the gist of the present invention may be It goes without saying that the invention can be implemented in various ways without departing from the scope.

10 First precast beam member (precast beam member)
12 Column and beam joint portion 12B Inner side surface of the column and beam joint portion on the indoor side 16 Mechanical joint 18 Mechanical fixing body 20 Beam portion 20A Outer surface of the beam portion on the indoor side 24 Balcony (jumping portion)
50 Second precast beam member (beam member)
50T Beam end face 52 Beam main reinforcement 56 Cast-in-place concrete part

Claims (3)

a column-beam joint part, a beam part extending from the column-beam joint part, a jumping-out part that springs out from the outside surface of the beam part on the outdoor side, and a part buried in the column-beam joint part, with one end side a precast beam member having a mechanical joint that opens an inner surface on the indoor side of the column-beam joint;
a beam member whose main beam reinforcement is connected to the one end side of the mechanical joint;
Precast beam joint structure with. The main beam reinforcement protrudes from a beam end surface of the beam member,
A cast-in-place concrete portion is provided between the inner surface of the column and beam joint portion and the beam end surface of the beam member,
The precast beam joint structure according to claim 1. A mechanical fixing body connected to the other end side of the mechanical joint is embedded in the column and beam joint part,
The precast beam joint structure according to claim 1 or claim 2.