JP2023081481A - Pca joined body and construction method thereof - Google Patents

Abstract

To provide a PCa joined body capable of eliminating a prolonged construction period due to filling of grout into a sheath pipe, and eliminating the need of repair and supplemental treatment caused by measures to maintain a standing posture of the PCa column, and a construction method thereof.SOLUTION: In a PCa joined body 50 in which a PCa column 10 and a PCa joint 20 are joined, the PCa joint 20 is arranged above the PCa column 10, a first unbonded PC steel 17 and a second unbonded PC steel 27 inserted into a first sheath pipe 16 and a second sheath pipe 26 are connected via a mechanical joint 35, and they are final tensioned, a first fixing plate 18 to which a first unbonded PC steel 17 is fixed is arranged at a first joint 41 between the PCa column 10 and the PCa joint 20, a second fixing plate 28 to which the second unbonded PC steel 27 is fixed is arranged above the PCa joint 20, and above and below the PCa joint 20, an endless steel band plate 24 extending in the circumferential direction of the PCa joint is provided.SELECTED DRAWING: Figure 1

Description

The present invention relates to a PCa joint and its construction method.

For example, when constructing column-to-beam joints between RC (Reinforced Concrete) columns and beams, and column-to-beam joints of hybrid structures between RC columns and S (Steel) beams by placing concrete on-site. In the case of high-rise buildings, this problem becomes even more pronounced. Therefore, both the upper and lower pillars and the joints that connect the two pillars are made of precast concrete (hereinafter referred to as “PCa” as appropriate), and the PCa pillars and PCa joints (both included in PCa members) are installed at the site. By transporting and assembling to form a PCa joined body, a connection method may be applied in which integration is achieved with only a minimum amount of grout filling. According to this method of constructing PCa joints, the construction period can be significantly shortened, including high-rise buildings, and since the column-to-beam joints are formed of PCa members, it is possible to construct buildings with high structural reliability. becomes possible. Among the construction methods of PCa joints, PCa members are tensioned with PC (Prestressed Concrete) steel rods, PC steel wires, or other tendons, and tightened together to form precast prestressed concrete (hereinafter referred to as "PCaPC" as appropriate). ) Construction period can be further shortened by constructing a joint. In this specification, a PCaPC assembly shall be included in a PCa assembly, and a PCaPC member which is a component thereof shall be included in a PCa member.

Here, in Patent Document 1, a reinforcing steel sheath pipe is embedded in advance in the joint portion between a column and a beam made of precast prestressed concrete members, and a predetermined amount of reinforcing steel is embedded at the same time or after joining the column and the beam. is housed in the reinforcing bar sheath pipe, and the joint is fixed by the tension of the PC steel material, and the reinforcing bar is fixed and held in the reinforcing bar sheath pipe to control the dispersion of cracks generated at the joint between the PC steel material and the reinforcing bar. A joint structure of precast prestressed reinforced concrete frames has been proposed. A PC cable, which is a PC steel material, is inserted through a metal sheath pipe embedded inside the columns and beams, and the sheath pipe is filled with grout after the PC cable is tensioned.

Japanese Patent No. 9-105173

In the conventional PCa joined body (PCaPC joined body) in which PCa members are joined together, including Patent Document 1, after the tendon inserted through the inside of the sheath tube provided in the PCa member is tensioned, the inside of the sheath tube By filling with grout, the prestressing tendon is brought into a bonded state, and the PCa joined body is constructed. Therefore, depending on the fact that grout filling work is required each time a PCa joint is constructed on each floor, the lengthening of the construction period becomes a problem.

In addition, for example, when constructing RC PCa columns, in order to maintain the standing posture of the PCa columns until the horizontal members are installed, a stay member is attached to the side surface of the PCa column, and one end of the stay member is attached. Provisions are made to fix it to fixtures installed on the slab. Therefore, after making the PCa column stand on its own, it is necessary to remove the stay member and the jig from the slab. When removing this jig, after removing the jig by scraping the concrete around the jig to fix the jig, the scraped part is repaired. Time is also an issue.

The present invention has been made in view of the above problems, and relates to a PCa joint in which a PCa column and a PCa joint provided with a steel beam are joined, and the construction period depends on filling the sheath pipe with grout. The object of the present invention is to provide a PCa joined body and a construction method thereof, which can eliminate the prolongation of a PCa pillar and eliminate the need for damage treatment caused by measures for maintaining the erected posture of a PCa column.

In order to achieve the above object, one aspect of the PCa conjugate according to the present invention is
A PCa joint in which a PCa column made of precast concrete and provided with a first sheath pipe is joined to a PCa joint made of precast concrete and provided with a second sheath pipe and a steel beam,
The PCa joint is arranged above the PCa column, and the first unbonded PC steel material and the second unbonded PC steel material respectively inserted through the first sheath tube and the second sheath tube that are in communication with each other are used as a machine. are connected via a type joint, and the first unbonded PC steel material and the second unbonded PC steel material are fully tensioned,
A first fixing plate to which the first unbonded PC steel material is fixed is disposed at a first joint between the PCa column and the PCa joint,
A second fixing plate to which the second unbonded PC steel material is fixed is arranged above the PCa joint,
Endless steel band plates extending in the circumferential direction of the PCa connection are provided above and below the PCa connection, and the steel beam extends laterally from between the upper and lower band plates. Characterized by

According to this aspect, the first unbonded PC steel material and the second unbonded PC steel material, which are respectively inserted into the first sheath pipe of the PCa column and the second sheath pipe of the PCa joint, are connected via a mechanical joint, and both Since the unbonded PC steel material is fully tensioned, it is possible to eliminate the lengthening of the construction period due to filling the sheath pipe with grout.

Here, the plan view shape of the PCa joint is, for example, a rectangle (rectangular or square). It has a protruding form. In addition, at the top and bottom of the PCa joint, endless steel band plates extending in the circumferential direction of the PCa joint are provided to improve the stress transmission performance from the steel beam to the PCa joint and PCa column. , the seismic performance of the building provided with the PCa joint can be enhanced. As described above, the PCa joined body of this embodiment includes the PCaPC joined body, the PCa joint includes the PCaPC joint, and the PCa column includes the PCaPC column.

Also, in another aspect of the PCa conjugate according to the present invention,
The first unbonded PC steel material is characterized in that it is pre-tensioned and then fully-tensioned.

According to this aspect, since the first unbonded PC steel material is temporarily tensioned and then fully tensioned, the PCa column can stand on its own due to the temporary tensioning of the first unbonded PC steel material in the construction process. It is possible to eliminate the need for the conventional measures for maintaining the standing posture of the column, that is, the measures to attach a stay member to the side of the PCa column and fix one end of the stay member to a jig installed on the slab. .

In addition, one aspect of the method for constructing a PCa joined body according to the present invention is
A PCa joint is constructed by joining a PCa column made of precast concrete and provided with a first sheath pipe and a PCa joint made of precast concrete and provided with a second sheath pipe and a steel beam. A construction method comprising:
The first unbonded PC steel material that is inserted into the first sheath tube of the PCa column and protrudes upward is temporarily tensioned, and the first fixing plate disposed in the first joint space above the PCa column is used to hold the first unbonded PC steel material. A step in which the PCa column is made self-supporting by fixing 1 unbonded PC steel material;
The second unbonded PC steel material that is inserted through the second sheath tube of the PCa joint and protrudes downward is connected to the first unbonded PC steel material that protrudes upward via a mechanical joint, and the second unbonded PC and a B step of fully tensioning the steel material and the first unbonded PC steel material, and fixing the second unbonded PC steel material with a second fixing plate disposed in the second joint space above the PCa joint. characterized by

According to this aspect, in step B, the first unbonded PC steel material and the second unbonded PC steel material, which are respectively inserted into the first sheath tube of the PCa column and the second sheath tube of the PCa joint, are connected via a mechanical joint. By fully tensioning both unbonded PC steel materials, it is possible to eliminate the lengthening of the construction period due to filling the sheath pipe with grout. In addition, in the A process, by temporarily tensioning the first unbonded PC steel material provided in the PCa column to make it self-supporting, the damage treatment that occurs when applying conventional measures to maintain the standing posture of the PCa column is unnecessary. can be

In another aspect of the method for constructing a PCa joined body according to the present invention,
In the step B, in the first joint space, curing is performed so that the joint material does not enter the first sheath pipe and the second sheath pipe communicating with the first joint space, and the It is characterized in that the joint material is placed and the main tensioning is performed after the joint material is cured.

According to this aspect, in the first joint space between the PCa pillar and the PCa joint, after curing is performed so that the joint material does not enter the first sheath pipe and the second sheath pipe communicating with the first joint space By driving the joint material in the first joint space, the joint in the first joint space can be constructed while maintaining the unbonded state of the tendon in the sheath pipe. Here, grout such as mortar can be used as the joint material.

In another aspect of the method for constructing a PCa joined body according to the present invention,
The above-mentioned A process and the above-mentioned B process are repeated to construct the PCa joined bodies corresponding to two or more layers.

According to this aspect, by repeating the A process and the B process and constructing the PCa joined body corresponding to two or more stories, the construction period can be shortened for each story. The advantage of shortening the construction period when constructing a skyscraper is even more pronounced.

In another aspect of the method for constructing a PCa joined body according to the present invention,
Endless steel band plates extending in the circumferential direction of the PCa connection are provided above and below the PCa connection,
The steel frame beam extends laterally from between the upper and lower band plates.

According to this aspect, since the PCa joint has a band plate, it is possible to construct a PCa joint having excellent stress transmission performance from the steel beam to the PCa joint and the PCa column.

As can be understood from the above description, according to the PCa joint and its construction method of the present invention, the lengthening of the construction period due to filling the sheath pipe with grout can be eliminated, and the standing posture of the PCa column can be maintained. It is possible to eliminate the need for bad processing that occurs due to measures to do so.

1 is an exploded perspective view of an example of a PCa joined body according to an embodiment, showing the inside of a PCa joint visible. FIG. 1 is a perspective view of an example of a PCa joined body according to an embodiment; FIG. FIG. 10 is a perspective view of another example of the PCa joint, showing the inside of the connector. 1 is a perspective view of an example of a hybrid frame with PCa conjugates according to embodiments; FIG. FIG. 2 is a process diagram of an example of a method for constructing a PCa joined body according to the embodiment; FIG. 6 is a process diagram of an example of the method for constructing the PCa joined body according to the embodiment, subsequent to FIG. 5 ; FIG. 7 is a process diagram of an example of the method for constructing the PCa joined body according to the embodiment, subsequent to FIG. FIG. 8 is a process diagram of an example of the method for constructing the PCa joined body according to the embodiment, subsequent to FIG. 7 ; FIG. 9 is a process diagram of an example of the method for constructing the PCa joined body according to the embodiment, subsequent to FIG. 8 ;

An example of a PCa joined body according to an embodiment and a construction method thereof will be described below with reference to the accompanying drawings. In addition, in the present specification and drawings, substantially the same components may be denoted by the same reference numerals, thereby omitting duplicate descriptions.

[PCa conjugate according to the embodiment]
First, an example of a PCa joined body according to an embodiment and an example of a PCa frame provided with the PCa joined body will be described with reference to FIGS. 1 to 4. FIG. Here, FIG. 1 is an exploded perspective view of an example of the PCa joined body according to the embodiment, showing the inside of the PCa joint visible, and FIG. 2 is a PCa joined body according to the embodiment. 1 is a perspective view of an example; FIG. FIG. 3 is a perspective view of another example of the PCa joint, showing the inside of the joint. Furthermore, FIG. 4 is a perspective view of an example of a hybrid frame provided with a PCa joint according to an embodiment.

A PCa joint (PCaPC joint) 50 is formed by connecting a PCa column (PCaPC column) 10 and a PCa joint (PCaPC joint) 20 to each other. For example, as shown in FIG. 4, the frame of each floor of a building is formed by arranging a plurality of PCa joints 50 side by side and connecting the PCa joints 50 by steel beams 60. The hybrid frame 100 is formed by stacking the layers. Here, the “hybrid frame structure” includes PCa columns 10 that are precast RC (Reinforced Concrete) columns, PCa joints 20 that are similarly precast RC joints, and PCa joints 20 It is a structure provided with a steel beam 60 that connects the More specifically, the PCa joint 20 can also be said to be of SRC (Steel Reinforced Concrete) construction, which incorporates a bracket 22 that forms part of a steel frame beam.

Returning to FIG. 1, the PCa column 10 has a rectangular parallelepiped PCa concrete body 11, and a plurality of (four in the illustrated example) first sheath pipes 16 are buried inside the PCa concrete body 11. A first unbonded PC steel material 17 is inserted through the first sheath tube 16 . Here, the first unbonded PC steel material 17 is a PC steel bar, but it may be a PC steel wire or the like. Here, although illustration is omitted, the PCa column 10 has a plurality of framing reinforcements extending in the vertical direction, and a plurality of rectangular frame-shaped ties surrounding the perimeter of each framing reinforcement.

The first unbonded PC steel material 17 protrudes upward from the upper end 11a of the PCa concrete body 11, and the first fixing plate 18 is fixed to the upper end 11a of the PCa concrete body 11 by tightening the nut 19 in a fully tensioned state. and the tension state of the first unbonded PC steel material 17 is maintained. Here, the first unbonded PC steel material 17 is subjected to two stages of tensioning, temporary tensioning and main tensioning, as will be described in detail below.

The first sheath pipe 16 is not filled with grout, and therefore the first unbonded PC steel material 17 is literally in an unbonded state inside the first sheath pipe 16 .

On the other hand, the PCa joint 20 has a rectangular parallelepiped PCa concrete body 21, as shown in FIG. , four second sheath tubes 26 are embedded, and a second unbonded PC steel material 27 is inserted through each of the second sheath tubes 26 . Here, the second unbonded PC steel material 27 is a PC steel bar.

The upper end of the first unbonded PC steel material 17 and the lower end of the second unbonded PC steel material 27 are connected to each other via a mechanical joint 35 such as a coupler.

The second unbonded PC steel material 27 protrudes upward from the upper end 21a of the PCa concrete body 21, and the second fixing plate 28 is fixed to the upper end 21a of the PCa concrete body 21 by tightening the nut 29 in the fully tensioned state. and the main tension state of the second unbonded PC steel material 27 is maintained. More specifically, the main tensioning causes both the first unbonded PC steel material 17 and the second unbonded PC steel material 27 to be main tensioned at the same time.

The second sheath pipe 26 is also not filled with grout, and therefore the second unbonded PC steel material 27 is literally in an unbonded state inside the second sheath pipe 26 .

As shown in FIGS. 1 and 2, the PCa joint 20 has steel beams 22A and 22B made of intersecting H-shaped steel embedded inside a rectangular parallelepiped PCa concrete body 21. Each steel beam 22A, 22B protrudes laterally from four side surfaces of the PCa concrete body 21 to form four brackets. Here, in the illustrated example, two steel beams 22B are welded to one continuous steel beam 22A, and the intersection of the cross-shaped steel beams 22 is at the center of the PCa concrete body 21 in plan view. However, the intersection of the cross-shaped steel beams 22 may be displaced from the center of the PCa concrete body 21 . Furthermore, the steel beams 22 may project from one to three of the four side surfaces.

A surrounding plate 23 made of steel is disposed in a region of the side surface of the PCa concrete body 21 that does not interfere with the bracket 22 projecting sideways, and the boundary between the surrounding plate 23 and the bracket 22 is welded. This surrounding plate 23 functions as a vertical stiffener.

With this configuration, all side surfaces of the PCa concrete body 21 of the PCa joint 20 are completely surrounded by the bracket 22 and the surrounding plate 23 projecting sideways. This surrounding plate 23 can increase the shear strength of the PCa joint 20 . Furthermore, in the manufacturing factory, since the PCa concrete body 21 is manufactured by filling the inside of the surrounding plate 23 with concrete from the state shown in FIG.

Above and below a surrounding plate 23 that surrounds the four side surfaces of the PCa connection 20, an endless steel band plate 24 (a rectangular frame shape in the illustrated example) extending in the circumferential direction of the PCa connection 20 is arranged, The upper and lower flanges of each bracket 22 are welded or bolted.

A rib plate 25 is welded to the inner side of the band plate 24, and the rib plate 25 is embedded in the PCa concrete body 21, so that the band plate 24 is firmly connected to the PCa concrete body 21. is planned.

By wrapping the surrounding plate 23 around the PCa concrete body 21 from the outside with the upper and lower band plates 24, the stress transmission performance from the steel frame beam 60 to the PCa joint 20 and the PCa column 10 can be enhanced.

A first joint 41 is formed between the PCa column 10 and the PCa joint 20 , and the first fixing plate 18 is embedded in the first joint 41 .

Here, the PCa connection 20 shown in FIGS. 1 and 2 can be referred to as a surrounding plate type PCa connection.

The PCa connection 20A shown in FIG. 3 is different from the PCa connection 20 in that the surrounding plate 23 is eliminated and a plurality of ties 32 are provided to surround a plurality of inner connection reinforcing bars 31 extending in the vertical direction. . Each tie 32 extends in the circumferential direction of the PCa joint 20A.

A vertical stiffener 33 is welded to the end of the bracket 22 to increase the shear resistance of the PCa joint 20A, like the surrounding plate 23.

The PCa joint 20A shown in FIG. 3 can be referred to as a lateral reinforcing bar type PCa joint.

Here, although illustration is omitted, instead of the ties 32 extending in the circumferential direction of the PCa joint 20A as shown in FIG. A configuration in which the assembling muscles are constrained from the outside with a plurality of U-shaped reinforcing muscles may be applied. Since this U-shaped reinforcing bar is inserted from the outside of a plurality of connecting reinforcing bars in the joint, it can be called an inserting bar type PCa joint.

According to the PCa joint 50, the first unbonded PC steel material 17 and the second unbonded PC steel material 27, which are respectively inserted into the first sheath pipe 16 of the PCa column 10 and the second sheath pipe 26 of the PCa joint 20, are mechanically Since both unbonded PC steel materials 17 and 27 are connected via the joint 35 and are fully tensioned, the lengthening of the construction period due to filling the sheath pipes 16 and 26 with grout can be eliminated.

Further, as will be described in detail below, after the PCa column 10 is erected, the first unbonded PC steel material 17 is temporarily tensioned. can stand on its own without a restraining member. Then, after installing the PCa joint 20 on the self-supporting PCa column 10 and connecting the first unbonded PC steel material 17 and the second unbonded PC steel material 27 via the mechanical joint 35, the first unbonded PC steel material 17 and the second unbonded PC steel 27 are pre-tensioned.

Due to this construction, the conventional measures for maintaining the erected posture of the PCa column 10, that is, the measures of attaching a stay member to the side surface of the PCa column and fixing one end of the stay member to a jig installed on the slab. You can eliminate the need for damage processing.

As shown in FIG. 4, a plurality of PCa joints 50 are arranged side by side for each floor, and the brackets 22 of each PCa joint 50 are connected to the steel beams 60 via splice plates 65 and high-tension bolts (not shown). Thus, the framework of each floor is formed. By vertically stacking the frames of each floor, the hybrid frame body 100 of the predetermined floor is formed. Here, FIG. 4 shows a part of the hybrid frame structure 100 that constitutes the first and second floors, for example. It becomes a hybrid frame structure.

According to the hybrid frame structure 100, it is possible to realize a large-span building and a high-rise building that take advantage of the respective advantages of the RC structure and the S structure. Further, since the band plate 24 is arranged around the PCa joint 20, high earthquake resistance performance can be realized with a simple reinforcing structure.

[Method for constructing PCa joined body according to the embodiment]
Next, an example of a method for constructing a PCa joined body according to the embodiment will be described with reference to FIGS. 5 to 9. FIG. Here, FIGS. 5 to 9 are process diagrams of an example of the method for constructing the PCa joined body according to the embodiment in this order. In the following description, a method of constructing the PCa joint 50 over two layers having a relationship between the lower floor and the upper floor will be described. It can be applied to two floors in a hierarchical relationship in all the floors from 1 to n floors.

In the method of constructing the PCa joint, first, as shown in FIG. 5, the PCa column 10 of the lower floor is erected on the slab (not shown).

The PCa column 10 includes a plurality of vertically extending framing reinforcements 11b inside the PCa concrete body 11, and a plurality of rectangular frame-shaped ties 11c surrounding each of the framing reinforcements 11b. , a plurality of first sheath tubes 16 described above, and a first unbonded PC steel material is inserted through each of the first sheath tubes 16 .

When the PCa column 10 of the illustrated example is the PCa column 10 of the first floor, a PC steel rod is embedded in a foundation slab (not shown), and a part of the steel rod protrudes above the foundation slab. When erecting the PCa column 10, the PCa column 10 is erected after connecting the upper end of the PC steel rod projecting above the foundation slab and the lower end of the first unbonded PC steel material 17 via a mechanical joint. On the other hand, when the PCa column 10 is a PCa column on the second floor or higher, the upper end of the second unbonded PC steel material and the lower end of the first unbonded PC steel material 17 protruding above the PCa joint on the lower floor (not shown) are After connecting via the mechanical joint, the PCa column 10 is erected.

After erecting the PCa column 10, each first unbonded PC steel material 17 is temporarily tensioned, and the first unbonded PC steel material 17 is attached to the first fixing plate 18 arranged in the first joint space 42 above the PCa column 10. By fixing, the PCa column 10 is made to stand on its own (above, step A).

Next, as shown in FIG. 6, the PCa joint 20 is lifted by a crane (not shown) and transferred above the self-supporting PCa column 10, and the second The unbonded PC steel material 27 is dropped downward, and the upper end of the corresponding first unbonded PC steel material 17 and the lower end of the second unbonded PC steel material 27 are connected via the mechanical joint 35 .

Below the second sheath tube 26 is a widened sheath tube 26A with an enlarged tube diameter, and the mechanical joint 35 is accommodated inside the widened sheath tube 26A.

Also, on the upper surface of the first fixing plate 18, a curing member 37 is installed to surround the first unbonded PC steel material 17 protruding upward, and the upper and lower second sheath pipes 26 and the first sheath pipes 16 are protected from the rear. Curing is performed so that the joint material cast in the first joint space 42 in the process does not enter. Here, for example, a bellows joint is applied to the curing member 37 .

Next, as shown in FIG. 7, the PCa joint 20 is erected while securing the first joint space 42 above the PCa pillar 10, and the joint material is driven into the first joint space 42 to form the second joint. 1st joint 41 is constructed. Here, grout such as mortar is applied to the joint material.

After constructing the first joint 41, the second unbonded PC steel material 27 is tensioned, so that the mutually continuous first unbonded PC steel material 17 and the second unbonded PC steel material 27 are fully tensioned.

By this main tension, the PCa column 10 and the PCa joint 20 are joined, and the PCa joined body 50 is constructed (above, step B).

In the method for constructing the PCa joined body, the above-described steps A and B are repeated to construct the PCa joined body 50 corresponding to two or more layers. Specifically, while suspending the PCa column 10 on the upper floor by a crane (not shown), it is transferred above the PCa joined body 50 that has been constructed, and the first unbonded PC steel material 17 in the first sheath pipe 16 of the PCa column 10 are dropped downward, and the corresponding upper end of the second unbonded PC steel material 27 and the lower end of the first unbonded PC steel material 17 are connected via the mechanical joint 35 .

Below the first sheath tube 16 is a widened sheath tube 16A with an enlarged tube diameter, and the mechanical joint 35 is accommodated inside the widened sheath tube 16A.

In addition, on the upper surface of the second fixing plate 28, a curing member 37 is installed to surround the second unbonded PC steel material 27 protruding upward, and the upper and lower first sheath pipes 16 and the second sheath pipes 26 are protected from each other. Curing is performed so that the joint material that is cast in the second joint space 44 in the process does not enter.

Next, as shown in FIG. 9, the PCa column 10 is erected while securing the second joint space 44 above the PCa joint 20, and a joint material is cast into the second joint space 44 to form the second joint. The second joint 43 is constructed. After that, the PCa joined body 50 on the upper floor is constructed by performing construction similar to that shown in FIGS.

According to the illustrated PCa joined body construction method, in step B, the first unbonded PC steel material 17 and the second By connecting the unbonded PC steel material 27 via a mechanical joint 35 and fully tensioning both the unbonded PC steel materials 17, 27, the lengthening of the construction period due to filling the sheath pipes 16, 26 with grout is eliminated. be able to.

Further, in the A process, by temporarily tensioning the first unbonded PC steel material 17 provided in the PCa column 10 to make it self-supporting, the damage that occurs when applying the conventional measures for maintaining the standing posture of the PCa column 10 processing can be eliminated.

Other embodiments may be possible in which other components are combined with the above-described configurations, etc., and the present invention is not limited to the configurations shown here. Regarding this point, it is possible to change without departing from the gist of the present invention, and it can be determined appropriately according to the application form.

10: PCa column (PCaPC column)
11: PCa concrete body 11a: upper end 11b: assembly bar 11c: tie bar 16: first sheath pipe 16A: widened sheath pipe 17: first unbonded PC steel (unbonded PC steel)
18: First fixing plate 19: Nut 20, 20A: PCa connection (PCaPC connection)
21: PCa concrete body 21a: upper end 22, 22A, 22B: steel beam (bracket)
23: Surrounding plate 24: Band plate 25: Rib plate 26: Second sheath tube 26A: Widened sheath tube 27: Second unbonded PC steel (unbonded PC steel)
28: Second fixing plate 29: Nut 31: Inner joint assembly bar 32: Tie bar 33: Vertical stiffener 35: Mechanical joint 37: Curing member (bellows joint)
41: First joint 42: First joint space 43: Second joint 44: Second joint space 50: PCa joint (PCaPC joint)
60: Steel beam 65: Splice plate 100: Hybrid frame

Claims (6)

A PCa joint in which a PCa column made of precast concrete and provided with a first sheath pipe is joined to a PCa joint made of precast concrete and provided with a second sheath pipe and a steel beam,
The PCa joint is arranged above the PCa column, and the first unbonded PC steel material and the second unbonded PC steel material respectively inserted through the first sheath tube and the second sheath tube that are in communication with each other are used as a machine. are connected via a type joint, and the first unbonded PC steel material and the second unbonded PC steel material are fully tensioned,
A first fixing plate to which the first unbonded PC steel material is fixed is disposed at a first joint between the PCa column and the PCa joint,
A second fixing plate to which the second unbonded PC steel material is fixed is arranged above the PCa joint,
Endless steel band plates extending in the circumferential direction of the PCa connection are provided above and below the PCa connection, and the steel beam extends laterally from between the upper and lower band plates. A PCa conjugate, characterized in that: 2. The PCa joined body according to claim 1, wherein the first unbonded PC steel material is pre-tensioned and then pre-tensioned. A PCa joint is constructed by joining a PCa column made of precast concrete and provided with a first sheath pipe and a PCa joint made of precast concrete and provided with a second sheath pipe and a steel beam. A construction method comprising:
The first unbonded PC steel material that is inserted into the first sheath tube of the PCa column and protrudes upward is temporarily tensioned, and the first fixing plate disposed in the first joint space above the PCa column is used to hold the first unbonded PC steel material. A step in which the PCa column is made self-supporting by fixing 1 unbonded PC steel material;
The second unbonded PC steel material that is inserted through the second sheath tube of the PCa joint and protrudes downward is connected to the first unbonded PC steel material that protrudes upward via a mechanical joint, and the second unbonded PC and a B step of fully tensioning the steel material and the first unbonded PC steel material, and fixing the second unbonded PC steel material with a second fixing plate disposed in the second joint space above the PCa joint. A method for constructing a PCa joined body, characterized by: In the step B, in the first joint space, curing is performed so that the joint material does not enter the first sheath pipe and the second sheath pipe communicating with the first joint space, and the 4. The method for constructing a PCa joined body according to claim 3, wherein a joint material is placed and said final tensioning is performed after said joint material has hardened. 5. The method for constructing a PCa joined body according to claim 3, wherein said step A and said step B are repeated to construct said PCa joined body corresponding to two or more floors. Endless steel band plates extending in the circumferential direction of the PCa connection are provided above and below the PCa connection,
6. The method for constructing a PCa joined body according to claim 3, wherein said steel beam extends laterally from between said upper and lower band plates.

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