JP7037394B2 - Joint structure of half PCa column and PCa wall or PCa beam - Google Patents

Description

The present disclosure relates to a joint structure of a half PCa column constructed by combining a precast concrete (PCa) member and cast-in-place concrete, and a PCa wall or a PCa beam.

When constructing a building, PCa members may be used to shorten the construction period. When joining a PCa member to another member, if the other member has a cast-in-place concrete structure, a formwork for that purpose is required and the workability is inferior. Therefore, various joining structures between PCa members have been proposed.

For example, Patent Document 1 discloses a joint structure between a PCa column and a PCa beam. The PCa pillar has a cavity provided in the center in a plan view and a through hole provided on the side surface so as to communicate with the cavity. By inserting the beam main bar of the PCa beam into the through hole and placing concrete in the cavity and the through hole, the PCa column and the PCa beam are joined to each other.

Japanese Unexamined Patent Publication No. 62-156462

With the structure described in Patent Document 1, it was difficult to confirm whether the through hole was filled with concrete. In addition, it is necessary to move the PCa beam laterally in order to insert the beam main bar into the through hole, but in the PCa beam arranged between the two PCa columns, this structure should be applied to both PCa beams. I couldn't do it, and I had to make some changes to one of the PCa pillars. Further, when this structure was applied to the PCa wall instead of the PCa beam, many horizontal bars had to be inserted into the corresponding through holes at the same time, which was troublesome to construct.

In view of such problems, it is an object of the present invention to provide a joint structure between a half PCa column and a PCa wall or a PCa beam having good workability.

At least some embodiments of the present invention are a joint structure (1,21) of a half PCa column (2,22) and a PCa wall (3) or a PCa beam (23) on at least one side. A first concrete portion (7,27) having a hollow portion (6,26) with an opening (10,32), a first pillar main bar (8,28) in which at least an intermediate portion is embedded in the first concrete portion. ), And the first PCa portion (4,24) including the first strip (9,31) arranged so as to intersect the first pillar main bar and at least partially embedded in the first concrete portion. A half PCa pillar having a cast-in-place concrete portion (5, 25) cast in the hollow portion, a second strip (11, 33) buried in the cast-in-place concrete portion, and a second concrete portion (12). , 34), and the second PCa portion (3,23) constituting the PCa wall or the PCa beam, including the lateral reinforcing bar (14,35) projecting laterally from the second concrete portion. The end portion of the lateral reinforcing bar protruding from the second concrete portion is embedded in the cast-in-place concrete portion, and the second band bar forms a lap joint with the portion of the first band bar arranged on the opening side. It is characterized by being arranged so as to. Here, "PCa" means precast concrete, and "lap joint" includes an empty lap joint.

According to this configuration, a large formwork is not required compared to the case where the entire column is constructed with cast-in-place concrete, and since there is space in the hollow part and the opening, cast-in-place around the lateral reinforcing bar is required. Good concrete filling and workability.

At least some embodiments of the present invention are characterized in that, in the above configuration, the hollow portion and the upper portion of the opening in the first concrete portion are open.

According to this configuration, the second PCa part can be moved so as to drop from above to below instead of laterally and arranged at a predetermined position. Therefore, after installing two PCa pillars adjacent to each other, the second PCa part is arranged between them. can do.

In at least some embodiments of the present invention, in any of the above configurations, the second PCa portion constitutes the PCa wall, intersecting the second strip, and at least a part thereof is the cast-in-place concrete portion or the above. It is characterized by further having an additional column main bar (15) buried in the second concrete portion.

According to this configuration, even if the first PCa section does not have the required amount of main bars in the column, by arranging the additional main bars, the half PCa column can secure the required amount of main bars.

In at least some embodiments of the present invention, in any of the first and second configurations, the second PCa portion constitutes the PCa beam, intersecting the second band and at least a part thereof. It is characterized by further having a second pillar main bar (29) embedded in the cast-in-place concrete portion.

According to this configuration, the column main bar can be arranged on the side joined to the PCa beam.

In at least some embodiments of the present invention, in any of the above configurations, the first concrete portion is configured such that the width of the opening is narrower than the width of the hollow portion, and the first concrete portion is configured to be smaller than the width of the hollow portion. The end portion of the first stirrups constituting the lap joint is characterized in that it extends in the width direction of the opening and is embedded in the first concrete portion. Alternatively, the first concrete portion is configured so that the width of the opening is equal to the width of the hollow portion, and the end portion of the first band bar constituting the lap joint with the second band bar is the first. 1 It is characterized in that it protrudes inward from the concrete portion and is buried in the cast-in-place concrete portion.

According to these configurations, the first band muscle and the second band muscle can exhibit the same performance as one band muscle.

According to the present invention, it is possible to provide a joint structure between a half PCa column and a PCa wall or a PCa beam having good workability.

Cross-sectional view showing the procedure for constructing the joint structure according to the first embodiment. Cross-sectional view showing the procedure for constructing the joint structure according to the first embodiment. Cross-sectional view showing the joining structure according to the first embodiment Cross-sectional view showing the joint structure according to the first modification of the first embodiment. Cross-sectional view showing the joint structure according to the second modification of the first embodiment. Cross-sectional view showing the joint structure according to the third modification of the first embodiment. Cross-sectional view showing the joint structure according to the fourth modification of the first embodiment. Cross-sectional view showing the joint structure according to the fifth modification of the first embodiment. Cross-sectional view showing the joint structure according to the second embodiment (IX-IX cross section of FIG. 12) A vertical sectional view showing a procedure for constructing a joint structure according to a second embodiment. A vertical sectional view showing a procedure for constructing a joint structure according to a second embodiment. Vertical cross-sectional view showing the joint structure according to the second embodiment (XII-XII cross section of FIG. 9)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show the procedure for constructing the joint structure 1 according to the first embodiment, and FIG. 3 shows the joint structure 1 according to the first embodiment. As shown in FIG. 3, the first embodiment is a joint structure 1 of a half PCa pillar 2 and a PCa wall 3.

The half PCa pillar 2 has a square pillar shape, and is a pillar having a half PCa structure having a first PCa portion 4 made of one PCa member and a cast-in-place concrete portion 5. The first PCa portion 4 has a first concrete portion 7 that defines the outer surface of the half PCa pillar 2 and a hollow portion 6 in which the cast-in-place concrete portion 5 should be placed, and the lower end side and the intermediate portion are the first. 1 Column main bar 8 buried in the concrete portion 7 and having the upper end side protruding from the first concrete portion 7 and a first band bar 9 arranged so as to intersect the column main bar 8 and buried in the first concrete portion 7. And have.

The first concrete portion 7 has four side walls that define the outer shape of the half PCa pillar 2 and the hollow portion 6. Since one side wall has an opening 10, the hollow portion 6 communicates with the outside. The upper and lower parts of the hollow portion 6 and the opening 10 are open. In the width of the PCa wall 3 in the wall thickness direction, the width of the opening 10 is narrower than the width of the hollow portion 6. That is, the first concrete portion 7 has a shape in which the center of one side of the square ring is removed in the cross-sectional view.

A mechanical joint (not shown) or the like is attached to the lower end side of the column main bar 8, and the column main bar 8 on the lower floor and the column main bar 8 on the upper floor are connected by this mechanical joint.

The first band muscle 9 is divided by the opening 10 because both ends thereof are located on opposite sides of the opening 10. Therefore, the second strip 11 is embedded in the cast-in-place concrete portion 5 so as to compensate for this division. Both ends of the second band bar 11 form a lap joint with both ends of the corresponding first band bar 9, respectively. Therefore, since stress is transmitted between the first band bar 9 and the second band bar 11, the first band bar 9 and the second band bar 11 as the shear reinforcing bar have the same performance as a single band bar. Demonstrate. Both ends of the first band bar 9 and the second band bar 11 are preferably bent at 180 ° in order to further improve the joint performance.

The PCa wall 3 has a second concrete portion 12 that defines the wall surface, and a vertical bar 13 and a horizontal bar 14 in which an intermediate portion is embedded in the second concrete portion 12. The thickness of the second concrete portion 12 is substantially equal to the width of the opening 10 in the wall thickness direction. The vertical bars 13 and the horizontal bars 14 are each double-arranged. The upper end side of the vertical bar 13 is connected to the lower end side of the vertical bar 13 of the PCa wall 3 on the upper floor by a mechanical joint (not shown) or the like. The distance between the two horizontal bars 14 adjacent to each other in the wall thickness direction is shorter than the width of the opening 10 in the wall thickness direction. The end portion of the horizontal bar 14 projects laterally from the second concrete portion 12, penetrates into the opening 10 and the hollow portion 6, and is embedded in the cast-in-place concrete portion 5. Therefore, the horizontal bar 14 is fixed to the half PCa column 2.

The construction procedure of the joint structure 1 will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the first PCa unit 4 is arranged at a predetermined position. Further, the second band bar 11 is bound to the portion of the horizontal bar 14 of the PCa wall 3 protruding from the second concrete portion 12.

Next, as shown in FIG. 2, the PCa wall 3 to which the second band bar 11 is attached is arranged at a predetermined position. At this time, since the hollow portion 6 and the upper portion of the opening 10 of the first PCa portion 4 are open, the PCa wall 3 to which the second band bar 11 is attached is moved so as to drop from above to a predetermined position. Can be placed in. Therefore, after the two first PCa portions 4 adjacent to each other are arranged at a predetermined position, the PCa wall 3 arranged between them can be moved from above to below and arranged at a predetermined position.

Next, as shown in FIG. 3, concrete is poured into the hollow portion 6 and the opening 10 to construct the cast-in-place concrete portion 5. At this time, since the second concrete portion 12 of the PCa wall 3 functions as a formwork, the workability is good. Further, the casting of the cast-in-place concrete into the opening 10 has better filling property than the case of injecting the concrete into the through hole (not shown) into which the reinforcing bar is inserted, and whether or not the concrete is filled. It is easy to check during casting, so it is easy to install. Further, the workability is improved by placing the cast-in-place concrete portion 5 at the same time as the slab using concrete for a slab (not shown). In this case, even if concrete for slabs having a relatively weak strength is used for the cast-in-place concrete portion 5, in order to satisfy the strength required for the concrete of the half PCa pillar 2 as a whole, the first concrete portion 7 is used. For the concrete, concrete having a strength higher than that required for the pillar is used, and the half PCa pillar 2 is used as a pillar having different strength.

FIG. 4 shows a joining structure 1 according to a first modification of the first embodiment. In the first modification, the shape of the second band streak 11 is U-shaped. As described above, the shape of the second band bar 11 can be changed to the extent that the first band bar 9 divided by the opening 10 can be supplemented and a lap joint can be formed with both ends of the first band bar 9.

FIG. 5 shows a joining structure 1 according to a second modification of the first embodiment. In the second modification, an additional column main bar 15 installed at the construction site is arranged in the opening 10 and is buried in the cast-in-place concrete portion 5. The second modification is adopted when the amount of the main bar is insufficient only by the pillar main bar 8 possessed by the first PCa portion 4.

FIG. 6 shows a joining structure 1 according to a third modification of the first embodiment. In the third modification, the width of the opening 10 in the wall thickness direction is narrower than the thickness of the second concrete portion 12. Since the length of the side wall having the opening 10 in the first concrete portion 7 in the wall thickness direction becomes long, the portion of the first zonal bar 9 arranged along the side wall can be lengthened. Since this portion is involved in the lap joint, the length of the joint between the first band bar 9 and the second band bar 11 becomes longer, and the joint becomes stronger. Further, a gap is unlikely to occur between the first concrete portion 7 and the second concrete portion, and it is easy to prevent concrete from leaking from the gap when placing concrete in the cast-in-place concrete portion 5.

FIG. 7 shows a joining structure 1 according to a fourth modification of the first embodiment. In the fourth modification, the end portion of the second concrete portion 12 plunges into the opening 10. It is preferable that the wall thickness of the second concrete portion 12 is smaller than the width of the opening 10 in the wall thickness direction so that the end portion of the second concrete portion 12 can be easily inserted into the opening 10. In this case, the gap between the end portion of the second concrete portion 12 and the surface defining the opening 10 of the first concrete portion 7 is filled by injecting grout (not shown). Further, the lower end portion and the intermediate portion of the additional column main bar 15 are embedded in the end portion of the second concrete portion 12. In this case, since the additional column main bar 15 is arranged at the PCa manufacturing factory, the workability at the construction site is improved. The additional column main bar 15 does not have to be provided.

FIG. 8 shows a joining structure 1 according to a fifth modification of the first embodiment. In the fifth modification, the first PCa portion 4 is composed of two first PCa members 4a and 4a, and two openings 10 and 10 are formed between the two first PCa members 4a and 4a. The two openings 10 and 10 are provided at positions facing each other, and the two PCa walls 3 and 3 are joined to the half PCa pillar 2 on opposite sides to each other. The two openings 10 may be arranged at an angle of 90 ° with respect to the center of the half PCa pillar 2 so that the two PCa walls 3 and 3 joined to the half PCa pillar 2 are orthogonal to each other. Further, the first PCa portion 4 is formed from three or four PCa members so that three or four openings 10 are formed, and the three or four PCa walls 3 are joined to the half PCa pillar 2. You may.

Next, the joining structure 21 according to the second embodiment of the present invention will be described with reference to FIGS. 9 to 12. 9 and 12 are a cross-sectional view and a vertical cross-sectional view of the joint structure 21, respectively, and FIGS. 10 and 11 are vertical cross-sectional views showing a procedure for constructing the joint structure 21. The second embodiment is a joint structure 21 of the half PCa column 22 and the PCa beam 23.

The half PCa pillar 22 has a square pillar shape, and is a pillar having a half PCa structure having a first PCa portion 24 made of one PCa member and a cast-in-place concrete portion 25. The first PCa portion 24 is a first concrete portion that defines the outer surface of the half PCa pillar 2 and defines the hollow portion 26 provided in the upper part of the half PCa pillar 2 so that the cast-in-place concrete portion 5 is placed. 27, a first pillar main bar 28 in which the lower end side and the middle portion are embedded in the first concrete portion 27 and the upper end side protrudes from the first concrete portion 7 without passing through the hollow portion 26, and the lower end side and the middle portion The second pillar main bar 29, which is buried in the first concrete portion 27 and protrudes from the first concrete portion 7 so that the upper end side is exposed to the hollow portion 26, and the first pillar main bar 28 and below the hollow portion 26. The lower strip 30 buried in the first concrete portion 27 so as to surround the second pillar main bar 29 and the first pillar main bar 28 located at the same height as the hollow portion 26 and intersecting the first pillar main bar 28. It has a first strip 31 embedded in the concrete portion 7.

The lower side of the first concrete portion 27 below the hollow portion 26 has a solid structure in which the side surface thereof coincides with the side surface of the half PCa pillar 22. The upper end side of the first concrete portion 27 defining the hollow portion 26 has a U-shape in a cross-sectional view in which an opening 32 is formed on the side where the PCa beam 23 is joined so that the hollow portion 26 communicates with the outside. None, the upper part of the hollow portion 26 and the opening 32 is open.

The upper end side of the first pillar main bar 28 and the second pillar main bar 29 is joined to the lower end side of the first pillar main bar 28 and the second pillar main bar 29 of the first PCa portion 4 on the upper floor by a mechanical joint 38 or the like.

The first band muscle 31 is divided by the opening 32 because both ends thereof are located on opposite sides of the opening 32. Therefore, the second strip 33 is embedded in the cast-in-place concrete portion 25 so as to compensate for this division. Both ends of the second band bar 33 form a lap joint with both ends of the corresponding first band bar 31, respectively. In order to transmit stress in the width direction of the PCa beam 23 between the first band bar 31 and the second band bar 33, both ends of the first band bar 31 are inside from the first concrete portion 27 in the width direction of the PCa beam 23. It protrudes toward and is buried in the cast-in-place concrete section 25. The second band bar 33 has a U-shape and is arranged so that the central portion intersects the second pillar main bar 29. Both ends of the second band 33 extend in parallel with the beam main bar 35 and are fixed to the cast-in-place concrete portion 25.

The PCa beam 23 includes a second concrete portion 34 that defines the outer shape of the beam, a beam main bar 35 in which an intermediate portion is embedded in the second concrete portion 34, and a stirrups 36 that surround the beam main bar 35 so as to intersect with each other. Has. The thickness of the second concrete portion 12 is substantially equal to the width of the opening 32. The end portion of the beam main bar 35 projects laterally from the second concrete portion 34, plunges into the opening 32 and the hollow portion 26, and is buried in the cast-in-place concrete portion 25. Therefore, the beam main bar 35 is fixed to the half PCa column 2.

The construction procedure of the joint structure 21 will be described with reference to FIGS. 10 to 12. As shown in FIG. 10, the first PCa unit 24 is arranged at a predetermined position. Further, the auxiliary bar 37 to which the second band bar 33 is bound is bound to the portion of the beam main bar 35 of the PCa beam 23 protruding from the second concrete portion 12.

Next, as shown in FIG. 11, the PCa beam 23 to which the second band bar 33 is attached is arranged at a predetermined position. At this time, since the hollow portion 6 and the upper portion of the opening 10 of the first PCa portion 24 are open, the PCa beam 23 to which the second band bar 33 is attached is moved so as to be dropped from above to a predetermined position. Can be placed in. Therefore, after the two first PCa portions 24 adjacent to each other are arranged at a predetermined position, the PCa beam 23 arranged between them can be moved from above to below and arranged at a predetermined position.

Next, as shown in FIG. 12, concrete is poured into the hollow portion 26 and the opening 32 to construct the cast-in-place concrete portion 25.

In the joining structure 21 according to the second embodiment, the target to be joined to the half PCa pillar 22 is replaced with the PCa beam 23 from the PCa wall 3 (see FIG. 1) with respect to the first embodiment. Is the same as in the first embodiment. Further, the configuration of the third and fifth modifications of the first embodiment and the configuration of the fourth modification excluding the additional column main bar 15 (see FIG. 7) may be applied to the second embodiment.

Although the description of the specific embodiment is completed above, the present invention can be widely modified without being limited to the above embodiment. For example, the second band muscle of the second embodiment may be the shape of the second band muscle of the first embodiment.

1,21: Joining structure 2,22: Half PCa pillar 3: PCa wall (second PCa part)
4,24: 1st PCa part 5,25: Cast-in-place concrete part 6,26: Hollow part 7,27: 1st concrete part 8: Column main bar (1st column main bar)
9, 31: 1st reinforcing bar 10, 32: opening 11, 33: 2nd reinforcing bar 12, 34: 2nd concrete part 14: horizontal reinforcing bar (lateral reinforcing bar)
15: Additional column main bar 23: PCa beam (second PCa part)
28: 1st column main bar 29: 2nd column main bar 35 Beam main bar (lateral reinforcing bar)

Claims (5)

It is a joint structure between a half PCa column and a PCa wall .
A first concrete portion having a hollow portion having an opening on at least one side, at least an intermediate portion arranged so as to intersect the first pillar main bar embedded in the first concrete portion, and the first pillar main bar. The first PCa part including the first stirrups buried in the first concrete part at least partially, the cast-in-place concrete part cast in the hollow part, and the cast-in-place concrete part buried in the cast-in-place concrete part. Half PCa pillar with 2 bands and
A second PCa portion that includes a second concrete portion and lateral reinforcing bars that project laterally from the second concrete portion and constitutes a PCa wall .
It has at least a portion of the cast-in-place concrete section or an additional column main bar embedded in the second concrete section that intersects the second strip .
The end portion of the lateral reinforcing bar protruding from the second concrete portion is embedded in the cast-in-place concrete portion.
The second band bar is a joint structure characterized in that it is arranged so as to form a lap joint with a portion of the first band bar arranged on the opening side. The first concrete portion is configured such that the width of the opening is equal to the width of the hollow portion.
A claim characterized in that an end portion of the first band bar constituting the second band bar and the lap joint protrudes inward from the first concrete portion and is embedded in the cast-in-place concrete portion. Item 1. The joint structure according to Item 1. It is a joint structure between a half PCa column and a PCa wall or a PCa beam.
A first concrete portion having a hollow portion having an opening on at least one side, at least an intermediate portion arranged so as to intersect the first pillar main bar embedded in the first concrete portion, and the first pillar main bar. The first PCa part including the first stirrups buried in the first concrete part at least partially, the cast-in-place concrete part cast in the hollow part, and the cast-in-place concrete part buried in the cast-in-place concrete part. Half PCa pillar with 2 bands and
It includes a second concrete portion and a lateral reinforcing bar projecting laterally from the second concrete portion, and has a PCa wall or a second PCa portion constituting a PCa beam.
The end portion of the lateral reinforcing bar protruding from the second concrete portion is embedded in the cast-in-place concrete portion.
The second band bar is arranged so as to form a lap joint with the portion of the first band bar arranged on the opening side.
The first concrete portion is configured such that the width of the opening is narrower than the width of the hollow portion.
A joint structure characterized in that an end portion of the first band bar constituting the second band bar and the lap joint extends in the width direction of the opening and is embedded in the first concrete portion. The second PCa portion constitutes the PCa beam, and the second PCa portion constitutes the PCa beam.
The joint structure according to claim 3 , further comprising a second column main bar that intersects the second band bar and is at least partially embedded in the cast-in-place concrete portion. The joint structure according to any one of claims 1 to 4, wherein the hollow portion and the upper portion of the opening in the first concrete portion are open.

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