JP2005061081A - Joint structure of pre-cast slab, and joining method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure of a precast slab capable of being easily jointed and disassembled, and to provide a method of joining the precast slab. <P>SOLUTION: Floor reinforcements 5 and anchor bolts 4a, arranged into a lattice-shape on a form formed in a specified size and then concrete is placed thereon, to manufacture a plurality of precast slabs 4 modularized in the desired dimension are manufactured. When the precast slabs 4 are put on the upper flange of a beam 3, a through hole 3c is formed at a concentric position, in the vertical direction with the anchor bolt 4a arranged at the under face of the precast slab 4; and a buffer material 8 is arranged on the upper flange of the beam 3, and the precast slab 4 is placed thereon, The anchor bolt 4a is installed so as to penetrate the through hole 3c. By fastening the anchor bolt 4a in the through hole 3c via a fastening means 9, the precast slab 4 is connected to the beam 3 of a structure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a joining structure of a precast slab that can be easily joined and disassembled, and a joining method of a precast slab.

Generally, as a method of constructing a floor slab of a structure using a precast slab, as shown in Patent Document 1, a stud bolt is arranged in advance on the upper surface of a beam constituting the frame structure of the structure, Generally, a precast slab is rigidly joined to a beam using a stud bolt and integrated.
JP 2001-107498 A

  However, in the above-mentioned configuration, when dismantling a structure that requires refurbishment, the precast slab is integrated into the beam via the stud bolt. It is easy to give and deformation. For this reason, it is difficult to secure the disassembled member in a reusable state, and in many cases, it cannot be recycled and must be disposed of as construction waste.

  In view of the above circumstances, an object of the present invention is to provide a precast slab joining structure and a precast slab joining method that can be easily joined and disassembled.

  The precast slab joint structure according to claim 1 is a precast slab joint structure provided in a steel structure having columns and beams, and the precast slab has an outer shape with a predetermined outer periphery. It is formed into a precast concrete structure that is modularized to a size located on the upper flange, and along the outer periphery at a predetermined arrangement interval from the outer periphery of the lower surface to a position where a predetermined amount of space is provided. A plurality of anchor bolts projecting vertically downward are provided, the beam is made of H-shaped steel, and the anchor bolt arranged on the lower surface of the precast slab when the precast slab is placed on the upper flange A plurality of through holes are formed at positions that are coaxial with each other in the vertical direction, and the precast slab is connected to the upper flange of the beam via a cushioning material. In addition to placing, and characterized in that Tightened through penetrating Tightened means the anchor bolt into the through-holes of the beam.

  The joint structure of the precast slab according to claim 2, wherein an end space between an anchor bolt and an outer periphery provided in the precast slab is longer than a length between a side surface of the upper flange constituting the beam and a web. In addition, an auxiliary plate is fixed to each of the both sides of the upper flange through fixing means so as to expand the width of the upper flange, and the auxiliary plate is precast. When the slab is placed, a plurality of through-holes are formed at positions that are coaxial with the anchor bolts arranged on the lower surface of the precast slab in the vertical direction. The beam is placed on the upper flange and the auxiliary plate of the beam, and the anchor bolt is passed through the through hole of the auxiliary plate and is fastened through the fastening means. It is.

  The joint structure of the precast slab according to claim 3, wherein a cutout portion is formed in a part of the outer periphery of the precast slab, and the cutout portion has a plan view shape and a plan view shape of the cutout portion. It is characterized in that a blindfold material that is substantially the same and has the same height as the precast slab is disposed.

  The precast slab joining method according to claim 4 is a precast slab joining method in which a precast slab is joined to a steel structure having columns and beams, and a beam whose outer periphery constitutes the structure in advance. An anchor having an outer shape sized to be located on the upper flange and projecting vertically downward along the outer periphery with a predetermined arrangement interval at a position where a predetermined amount of end space is provided from the outer periphery of the lower surface A plurality of precast slabs provided with a plurality of bolts are manufactured, and the upper flange of the beam is coaxial with the anchor bolts arranged on the lower surface of the precast slab in the vertical direction when the precast slab is placed. A first step of providing a plurality of through holes with respect to the position, and the anchor bolts of the precast slab penetrate through the through holes of the beam. A second step of disposing a plurality of precast slabs on the flange via a cushioning material, and a third step of fastening anchor bolts of the precast slabs to the through holes via fastening means. It is a feature.

  6. The precast slab joining method according to claim 5, wherein in the first step, instead of the step of providing a through hole in the beam, both sides of the upper flange are paired so as to expand the width of the upper flange of the beam. The auxiliary plate is fixed to the auxiliary plate via a fixing means, and when the precast slab is placed on the auxiliary plate, the auxiliary plate is placed at a position coaxial with the anchor bolt arranged on the lower surface of the precast slab. On the other hand, a plurality of through holes are provided, and in the second step, a buffer material is provided on the upper flange of the beam and the upper surface of the auxiliary plate so that the anchor bolt of the precast slab passes through the through hole of the auxiliary plate. It is characterized by arranging a plurality of precast slabs.

  According to the joining structure of the precast slab according to claim 1, the fastening means for fastening the precast slab and the beam is removed, and the precast slab can be easily lifted from the structure by lifting the precast slab with a heavy machine such as a crane. Because it can be dismantled, it can be stored in a state that can withstand reuse without deforming the construction materials such as pillars and beams when the structure is dismantled. It will be possible to contribute greatly.

  Since the outer shape of the precast slab is modularized so that the outer periphery is positioned on the upper flange of the predetermined beam, the precast slab is modularized in units of structures. The cost can be greatly reduced, and the workability can be improved by simplifying the work such as loading / unloading and installation, which can greatly contribute to the reduction of the construction cost and the construction period.

  In addition, since the precast slab is placed on the upper flange of the beam via a cushioning material, it can prevent rattling that tends to occur between the two, and also provides the soundproofing effect of the structure itself. It becomes possible.

  According to the joining structure of the precast slab according to claim 2, since the width of the upper flange constituting the beam is expanded by using the auxiliary plate, the outer periphery of the precast slab and the arrangement position of the anchor plate are Since it is possible to sufficiently secure the end space formed between them, it is possible to suppress defects that are likely to occur in the vicinity of the outer periphery of the precast slab due to an external load such as an earthquake, and it is possible to prevent the precast slab from falling off. .

  According to the joint structure of the precast slab according to claim 3, even when a non-flat region is formed in a part of the upper flange of the beam, the precast slab that contacts the region is cut out, and the notch Therefore, it is possible to easily dispose the precast slab regardless of the configuration of the beam.

  According to the precast slab joining method according to claim 4 and claim 5, since it is not necessary to provide a stud gibber on the upper flange of the beam as in the prior art, there is no need to perform complicated operations such as welding. In addition, since it is not necessary to perform the on-site operation of the concrete in which the stud gibber and the precast slab are integrated, the work efficiency is greatly improved, and it is possible to greatly contribute to the reduction of the construction cost and the construction cost.

  The joining structure of the precast slab and the joining method of the precast slab according to the present invention are shown in FIGS. According to the present invention, a precast slab used for a steel structure composed of columns and beams includes a plurality of anchor bolts at predetermined positions on the lower surface, and a plurality of the beams are arranged on the upper flange at the same arrangement interval as the anchor bolts. The precast slab is placed on the upper flange of the beam, the anchor bolt is passed through the through hole of the upper flange, and the two are fastened through the fastening means. It is set as the structure which can be attached or detached easily with respect to.

(First embodiment)
As shown in FIG. 1, a steel structure 1 including a column 2 made of steel and a beam 3 made of H-shaped steel has a plurality of precast slabs 4 disposed on the upper surface of the beam 3.
As shown in FIG. 2, the precast slab 4 is made of a precast concrete structure on a flat plate formed by embedding a plurality of floor reinforcing bars 5 assembled in a lattice shape with concrete 6.
As shown in FIG. 1, the precast slab 4 has an outer shape on the outer periphery of two large beams 3a adjacent in parallel and two small beams 3b adjacent in parallel. It is modularized in a rectangular shape in plan view with a size located on the flange. Note that the size of the modularized precast slab 4 is not necessarily limited to the above-described one, and the outer periphery is modularized so that it is positioned on the upper flanges of the four large beams 3a of the structure 1. If the outer periphery is formed in a shape that is located on the upper flange of any given beam 3, the size and shape are not particular.

In the vicinity of the outer periphery of such a precast slab 4, there are provided a plurality of anchor bolts 4a arranged so that one end protrudes vertically downward from the lower surface. The anchor bolts 4a, as shown in FIG. 3, in a position from the outer periphery of the pre-cast slab 4 is provided with an end free L ₁ of a predetermined amount, so as to extend along the length direction of each of the outer peripheral, a predetermined arrangement interval A plurality are provided. End amount of free L ₁ provided between the outer periphery of the anchor bolts 4a and precast slabs 4, as shown in FIG. 3, when placing the outer periphery of the pre-cast slab 4 on the upper flange of the beam 3 In addition, the anchor bolt 4a is determined within a length range in which the anchor bolt 4a contacts the upper flange of the beam 3.

  In the present embodiment, as shown in FIG. 2, the floor reinforcing bar 5 constituting the precast slab 4 uses a reinforcing bar with a head whose diameter is enlarged at the end, but it is not necessarily limited to this. Instead, any reinforcing bar may be used as long as it has a structure with a high fixing effect with the concrete 6. Further, when the precast slab 4 is brought into the field or installed at a predetermined position, the outer periphery of the precast slab 4 is precast on the outer peripheral surface for the purpose of preventing the occurrence of chipping of the outer peripheral edge and peeling failure. Although the width stopper 7 generally used for the member is provided, it is not always necessary to provide it.

As shown in FIG. 1, the precast slab 4 having such a configuration is arranged in parallel on the upper surface of the beam 3 in the X direction and the Y direction of the structure 1 with the outer peripheral surfaces facing each other. . In the beams 3 on which these precast slabs 4 are placed, through holes 3c through which anchor bolts 4a provided in the precast slabs 4 pass are spaced in the longitudinal direction of the upper flange with the same spacing as the anchor bolts 4a. A plurality are formed.
Therefore, as shown in FIG. 3, the precast slab 4 is arranged so that the outer periphery is positioned on the upper flange of the beam 3 with the anchor bolt 4a passing through the through hole 3c of the beam 3. The anchor bolt 4a is fastened to the through-hole 3c via the fastening means 9 such as a nut, thereby joining to the beam 3. In this case, the pre-cast slab 4 thereof adjacent consideration workability during removal, as shown in FIG. 3, the clearance L ₂ of a predetermined amount is provided. With such a configuration, the inertial force generated in the precast slab 4 is transmitted to the beam 3 through the fastening means 9.

  Incidentally, as shown in FIG. 3, the precast slab 4 is arranged on the upper flange of the beam 3 via a cushioning material 8 constituted by a rubber plate or the like. The cushioning material 8 absorbs a gap that is likely to occur between the lower surface of the precast slab 4 and the upper flange of the beam 3, and prevents rattling between the two by absorbing the gap. Moreover, it functions also as a soundproofing mechanism of the structure 1 itself.

A method for joining the precast slab 4 having the above-described configuration to the structure 1 will be described below.
In the first step, in a factory or on-site site, etc., a floor rebar 5 arranged in a grid and a plurality of anchor bolts 4a are arranged on a mold (not shown) formed in a predetermined size, and then concrete. As shown in FIG. 2, a plurality of precast slabs 4 modularized to a desired size are manufactured. At this time, the size of the mold is formed in advance so as to be approximately the same size as a square area in plan view located on the upper flange of the predetermined beam 3 constituting the structure 1 on the four sides.
On the other hand, as shown in FIG. 1, when the precast slab 4 is placed on the upper flange of the beam 3, anchor bolts 4a arranged at a predetermined arrangement interval on the lower surface of the precast slab 4; A plurality of through holes 3c are provided at positions that are coaxial in the vertical direction.

  In the second step, the cushioning material 8 is disposed on the upper flange of the beam 3, the precast slab 4 is placed on the upper flange of the beam 3, and the anchor bolt 4 a is provided on the beam 3. It is installed so as to penetrate through the through hole 3c.

  In the third step, the anchor bolt 4 a of the precast slab 4 is fastened to the through hole 3 c provided in the beam 3 via the fastening means 9, so that the precast slab 4 is joined to the beam 3 of the structure 1. .

(Second Embodiment)
In the first embodiment, the configuration in which the anchor bolt 4a of the precast slab 4 is fastened to the through hole 3c provided in the upper flange of the beam 3 via the fastening means 9 is shown. _When the length of ₁ is not sufficient, the vicinity of the outer periphery tends to be lost due to an earthquake or the like. Therefore, in the second embodiment, detailing the bonding structure and bonding method of the possible pre-cast slab 4 to secure the end of free L ₁ of sufficient length.

As shown in FIG. 3 (b), the anchor bolt 4a provided near the outer periphery of the precast slab 4 is along the length direction of each outer periphery and vertically below the lower surface, as in the first embodiment. A plurality are provided with a predetermined arrangement interval so as to protrude in the direction. End free L ₁ provided between the outer periphery of the anchor bolts 4a and precast slabs 4 is secured longer than the length between its length the flange side and the web on the beam 3, Even when the outer periphery of the precast slab 4 is arranged on the upper surface of the beam 3, the anchor bolt 4 a does not contact the upper flange of the beam 3.

  On the other hand, in the upper flange of the beam 3 constituting the structure 1, an auxiliary plate in which a plurality of through holes 10a having the same arrangement interval as the anchor bolts 4a provided in the precast slab 4 are formed in the longitudinal direction. 10 are fixed to each side of the upper flange through fixing means such as welding in a pair so as to expand the width of the upper flange. In the present embodiment, the auxiliary plate 10 uses a steel plate, but is not necessarily limited to this, and is a highly rigid material that is not easily deformed by an external force, such as an angle generally used as a building material. Any of them may be used.

These are placed on the upper flange of the beam 3 and the upper surface of the auxiliary plate 10 with the precast slab 4 passing through the anchor bolt 4a through the through hole 10a of the auxiliary plate 10 fixed to the beam 3. By fastening the anchor bolt 4a to the through hole 10a via the fastening means 9 such as a nut, the auxiliary plate 10 is joined to the fixed beam 3. With such a configuration, the inertial force generated in the precast slab 4 is transmitted to the beam 3 through the fastening means 9 and the auxiliary plate 10.
The beam 3 may be either a large beam 3a or a small beam 3b, and between the precast slab 4 and the upper flange of the beam 3 and the upper surface of the auxiliary plate 10 as in the first embodiment. The buffer material 8 is disposed.

A method for joining the precast slab 4 having the above-described configuration to the structure 1 will be described below.
In the first step, a plurality of precast slabs 4 are manufactured by the same method as in the first embodiment.
On the other hand, instead of providing the through holes 3c in the upper flange, the beam 3 has a plurality of through holes 10a having the same arrangement interval as the anchor bolts 4a provided in the precast slab 4 on both side surfaces of the upper flange. Are fixed in the longitudinal direction through a fixing means. At this time, when the precast slab 4 is placed, the auxiliary plate 10 for the upper flange of the beam 3 so that the anchor bolt 4a and the through hole 10a provided on the lower surface of the precast slab 4 are coaxial in the vertical direction. The fixing position is adjusted as appropriate.

  In the second step, the shock absorber 8 is disposed on the upper flange of the beam 3 and the upper surface of the auxiliary plate 10, and the anchor bolt 4 a is attached to the auxiliary plate with the outer periphery positioned on the upper flange of the beam 3. The precast slab 4 is installed on the upper flange of the beam 3 and the upper surface of the auxiliary plate 10 so as to penetrate through the ten through holes 10a.

  In the third step, the anchor bolt 4 a of the precast slab 4 is fastened to the through hole 10 a of the auxiliary plate 10 via the fastening means 9, so that the precast slab 4 is joined to the beam 3 of the structure 1.

By the way, as shown in FIG. 1, the steel-structured large beams 3 constituting the structure 1 may be connected by connecting the large beams 3 a adjacent to each other in the length direction by bolting with high-strength bolts 13 via splice plates 12. In many cases, a non-flat upper surface is formed on a portion of the upper flange. The precast slab 4 cannot be placed on the upper flange that is not flat due to the protrusions of the splice plate 12 and the high strength bolt 13.
Therefore, the precast slab 4 is located at a position where it abuts the connecting portion of the large beams 3a when placed at a predetermined position of the large beams 3a, that is, within a width range that is coaxial with the upper flange of the large beams 3a at a part of the outer periphery. A notch 4b as shown in FIG. 1 is provided in advance. Thereby, the precast slab 4 can be joined to the large beam 3a without contacting the connecting portion between the large beams 3a.

However, when the precast slab 4 having a notch part 4b in part is joined onto the large beam 3a, a step is generated in the notch part 4b. For this reason, in this Embodiment, the steel blindfold material 11 is arrange | positioned in this notch part 4b. As shown in FIG. 4, the blindfold material 11 has a plan view shape covering a notch portion of the precast slab 4, or a plan view shape covering a region surrounded by the notch portion 4 b of the adjacent precast slab 4, and a precast It has the same height as the member thickness of the slab 4, is formed in a box shape with an open bottom surface, and has at least the same strength as the precast slab 4 against the pressing force in the out-of-plane direction. It is configured.
By joining such a blindfold material 11 together with the precast slab 4 onto the beam 3, a roller that covers the connecting portion of the large beam 3a with the blindfold material 11 can be formed, so that a floor slab having a uniform plane is formed. .

As shown in FIG. 4, considering the ease of removing the precast slab 4, the blindfold material 11 has a predetermined amount of clearance L ₃ without coming into contact with the adjacent precast slab 4. Deploy.
Further, the auxiliary plate 10 may be fixed to both sides of the upper flange of the large beam 3a by using fixing means such as welding as shown in FIG. 3B, but as shown in FIG. You may utilize the high strength volt | bolt 13 used for the connection of the said big beams 3a. Specifically, the width of the auxiliary plate 10 is set to be larger than the distance between the web of the large beam 3a and the side surface of the upper flange, and in addition to the through hole 10a, the height of the auxiliary plate 10 is set at a predetermined position so as to be parallel thereto. A plurality of through holes 10b for high-strength bolts through which the force bolts 13 pass are formed. When connecting the adjacent large beams 3a, the splice plate 12 is disposed on the upper surface of these upper flanges so as to straddle both, and the auxiliary plate 10 is disposed on the lower surface. Tighten up. Thereby, the through-hole 10a is formed in the position which protrudes from the upper flange of the large beam 3a of the auxiliary plate 10 to the side. As described above, in this case, when the precast slab 4 is placed, the anchor bolt 4a and the through hole 10a provided on the lower surface of the precast slab 4 are coaxial in the vertical direction. The fixing position of the auxiliary plate 10 with respect to the upper flange of the beam 3 is appropriately adjusted.

  According to the configuration described above, by removing the fastening means 9 that fastens the precast slab 4 and the beam 3 or the auxiliary plate 10 fixed to the beam 3, and lifting the precast slab 4 with a heavy machine such as a crane, Since the precast slab 4 can be easily dismantled from the structure 1, it can be stored in a state that can withstand reuse without deforming the construction materials such as the pillar 2 and the beam 3 when the structure 1 is disassembled. It can contribute to the recycling of construction materials and can greatly contribute to global environmental conservation.

  Since the outer shape of the precast slab 4 is modularized so that the outer periphery is positioned at the upper flange of the beam 3, the precast slab 4 is modularized in units of structures. The manufacturing cost can be greatly reduced, and the workability can be improved by simplifying the work such as loading / unloading and installation, which can greatly contribute to the reduction of the construction cost and the construction period.

  Further, since the precast slab 4 is placed on the upper flange of the beam 3 via the cushioning material 8, it is possible to prevent rattling that tends to occur between the two, and the soundproofing effect of the structure 1 itself. Can also be given.

  The floor reinforcing bar 5 provided in the precast slab 4 uses a headed reinforcing bar whose end is enlarged in diameter, so that the fixing effect with the concrete constituting the precast slab 4 is high. It is possible to prevent concrete cracking and destruction that are likely to occur in the vicinity of the outer periphery.

  Since the outer peripheral surface of the precast slab 4 is provided with a width stopper 7, when the precast slab 4 is transported to the site or installed at a predetermined position, the occurrence of chipping or peeling failure at the outer periphery is prevented. It becomes possible to do.

Moreover, since the width | variety of the upper flange which comprises the beam 3 is expanded by using the auxiliary plate 10 on both sides of the upper flange which comprises the beam 3, the outer periphery of the precast slab 4 and arrangement | positioning of the said anchor plate 4a Since it is possible to sufficiently secure the end space L ₁ formed between the position and the position, it is possible to suppress the loss that tends to occur in the vicinity of the outer periphery of the precast slab 4 due to an external load such as an earthquake. It becomes possible to prevent.

  The method of joining the precast slab 4 to the structure 1 does not require the provision of a stud gibber on the upper flange of the beam 3 as in the prior art, so there is no need to perform complicated operations such as welding, Since it is not necessary to perform the on-site work of the concrete in which the precast slab 4 is integrated, the work efficiency is greatly improved, and it is possible to greatly contribute to the reduction of the construction cost and the construction cost.

It is a figure which shows the joining structure to the structure of the precast slab which concerns on this invention. It is a figure which shows the detail of the precast slab which concerns on this invention. It is a figure which shows the detail of the junction part of the precast slab which concerns on this invention, and a beam. It is a figure which shows the detail of joining with the connection part of the precast slab which concerns on this invention, and a large beam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Structure 2 Column 3 Beam 3a Large beam 3b Small beam 3c Through-hole 4 Precast slab 4a Anchor bolt 4b Notch part 5 Floor reinforcement 6 Concrete 7 Width stopper 8 Buffer material 9 Tightening means
10 Auxiliary plate 10a Through hole 10b High strength bolt through hole 11 Blindfold 12 Splice plate 13 High strength bolt

Claims (5)

A precast slab joint structure provided in a steel structure with columns and beams,
The precast slab is formed into a precast concrete structure whose outer shape is modularized so that the outer periphery is positioned on the upper flange of the predetermined beam, and a predetermined amount of edge space is provided from the outer periphery of the lower surface. A plurality of anchor bolts projecting vertically downward along the outer periphery at a predetermined arrangement interval are provided at the positions,
The beam is made of H-shaped steel, and when a precast slab is placed on the upper flange, a plurality of through holes are formed at positions that are coaxial with the anchor bolts arranged on the lower surface of the precast slab in the vertical direction. Is formed,
A precast slab joining structure characterized in that the precast slab is placed on the upper flange of the beam via a cushioning material, and the anchor bolt is passed through a through hole of the beam and fastened by a fastening means. . In the joint structure of the precast slab according to claim 1,
The end space between the anchor bolt and the outer periphery provided in the precast slab is secured longer than the length between the side surface of the upper flange constituting the beam and the web, and
Auxiliary plates are fixed to each side of the upper flange via a fixing means so as to extend the width of the upper flange to the beam.
In addition, when the precast slab is placed on the auxiliary plate, a plurality of through holes are formed at positions that are coaxial with the anchor bolt arranged on the lower surface of the precast slab in the vertical direction.
The precast slab is mounted on the upper flange and the auxiliary plate of the beam via a cushioning material, and the anchor bolt is passed through the through hole of the auxiliary plate and fastened by a fastening means. Bonding structure. In the joint structure of the precast slab according to claim 2,
A notch is formed in a part of the outer periphery of the precast slab,
A joint structure for a precast slab, wherein a blindfold material having a plan view shape substantially the same as a plan view shape of the notch portion and a height substantially the same as the precast slab is disposed in the notch portion. A precast slab joining method for joining a precast slab to a steel structure with columns and beams,
The outer periphery has an outer shape that is large enough to be positioned on the upper flange of the beam that constitutes the structure, and is placed outside the outer periphery of the lower surface with a predetermined arrangement interval at a position where a predetermined amount of end space is provided. While producing multiple precast slabs with multiple anchor bolts that protrude vertically downward along the periphery,
In the upper flange of the beam, when a precast slab is placed, a first through hole is provided at a position that is coaxial with the anchor bolt disposed on the lower surface of the precast slab in the vertical direction. And the process of
A second step of disposing a plurality of precast slabs on the upper flange of the beam via a cushioning material so that anchor bolts of the precast slab pass through the through hole of the beam;
A precast slab joining method comprising: a third step of fastening an anchor bolt of a precast slab to the through hole via a fastening means. It is a joining method of the precast slab of Claim 4,
In the first step, instead of the step of providing the through hole in the beam, the auxiliary plate is fixed to both sides of the upper flange in a pair so as to expand the width of the upper flange of the beam through fixing means. In the auxiliary plate, when a precast slab is placed, a plurality of through holes are provided for a position that is coaxial with the anchor bolt arranged on the lower surface of the precast slab in the vertical direction,
In the second step, a plurality of precast slabs are arranged on the upper flange of the beam and the upper surface of the auxiliary plate so as to pass through the anchor bolts of the precast slab through the through holes of the auxiliary plate. Joining method of precast slab.

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