JP2023127674A - Connecting method between precast column member and precast connection member - Google Patents

Abstract

To provide a connecting method for integrally connecting a precast column and a precast connection member through minimum work at a high place and on scaffolds.SOLUTION: A connecting method for connecting a precast column member 10 where a plurality of column main bars 1 project from an upper surface of a column concrete and a precast connection member 20 having a through hole 2 holding the column main bars 1 comprises steps of: placing the precast connection member 20 on the precast column member 10 while holding the column main bars 1 in the through hole 2 so as to form a grout filling space 30 between an upper surface of the precast column member 10 and a lower surface of the precast connection member 20, of which side surface is partitioned with elastic sealing material 15; and integrally connecting the precast column member 10 and the precast connection member 20 by filling grout with a lower specific gravity than that of the precast connection member 20 into the grout filling space 30 through the through hole 2.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for joining a column precast member and a joint precast member that can integrally join a precast reinforced concrete column member and a joint member with minimal work at heights or on scaffolding.

Conventionally, column precasting has been used as a joining method to integrally join a precast reinforced concrete column (column precast member) to a precast reinforced concrete (hereinafter simply referred to as precast) joint part member (joint part precast member). There is a method of placing a joint precast member on the member with a predetermined clearance, and filling the clearance with grout to integrate the joint. In this joining method, in order to cover the outer periphery of the clearance provided at the joint, a square rod-shaped sealant such as a crosspiece is used to form a formwork (Patent Document 1), or a seal with a rubber crimping piece attached is used. A method has been disclosed in which metal fittings are combined to form a grid shape to cover the outer periphery of a precast member (Patent Document 2), and the clearance portion of the joint is filled with mortar. In addition, a method using an elongated air tube as a sealing material has also been proposed.

Utility Model Publication No. 6-49657 Japanese Patent Application Publication No. 5-311737

In the techniques disclosed in Patent Documents 1 and 2, in order to provide sealing material (formwork) etc. on the entire outer periphery of the upper end of the precast column, a worker climbs up to the top of the column using an aerial work vehicle, scaffolding, etc. It was necessary to work on the entire circumference of the column. In addition, in order to deploy and install aerial work vehicles, scaffolding, etc., it was necessary to provide a stable concrete work floor, etc., and incidental work was required to install these.

Furthermore, in order to integrate the column precast member and the joint precast member, it is necessary to fill the joint precast member with grout by applying a predetermined pressure from the top (upper surface) or the bottom thereof. In that case, grout having a specific gravity equal to or higher than that of the joint precast member may be used. In this case, it was necessary to firmly fix the precast joint member above the portion to be filled with grout so that it would not be lifted up by the grout filling pressure and displaced from the installed position.

SUMMARY OF THE INVENTION Therefore, the purpose of the present invention is to solve the problems of the above-mentioned conventional techniques, and to provide a column that allows a precast column and a joint member to be fixedly joined together with a minimum of work at heights and work on scaffolding. An object of the present invention is to provide a method for joining a precast member and a joint precast member.

The joining method of the present invention is a method for joining a column precast member having a plurality of column main reinforcements protruding from the upper surface of the column concrete and a joint part precast member having a through hole for holding the column main reinforcements. The main pillar reinforcement is held in the through-hole so that a grout-filled space whose side surfaces are partitioned by a sealing material is formed between the upper surface and the lower surface of the precast member for the joint part. A precast member is placed on the column precast member, and grout having a specific gravity lower than that of the joint precast member is filled into the grout filling space through the through hole, and the column precast member and the finish are filled. It is characterized by integrally joining the mouth precast member.

The grout filling space is provided with a widthwise widened portion on the upper end side of the column precast member and the lower end side of the joint precast member, and the width of the width is increased between the upper surface of the column precast member and the lower surface of the joint precast member. It is preferable that the grout filling recess formed in at least one side and the sealing material attached to ensure the columnar cross section of the columnar precast member are partitioned.

The grout filling space includes a seal attached along the upper surface of the pillar precast member, the lower surface of the joint precast member, and the inner circumferential surface of the lower end of a closing plate that protrudes from the lower surface of the joint precast member. It is preferable that it is divided by a stopper.

The sealing material is elastically deformed when the joint precast member is placed on the pillar precast member, and comes into close contact with the pillar precast member and the joint precast member to fill the grout filling space. Preferably, it is an elastic sealing material that partitions the side surfaces.

It is preferable that the sealing material is a formwork member that is held on the outer circumferential surface of the column precast member or the joint precast member and partitions a side surface of the grout filling space.

It is preferable that the precast joint part member has a grout filling hole arranged in parallel with the through hole.

Filling and flowing down the grout from the upper end of the joint precast member through the through hole to fill the grout filling space, and confirming that the grout is overflowing from the through hole in which the column main reinforcement is held. preferable.

FIG. 2 is a perspective view showing a column precast member and a joint precast member before joining in a first embodiment of the present invention, so that a grout-filled recess formed on the column upper surface can be seen. FIG. 2 is a side view showing the structure of the column precast member and the joint precast member shown in FIG. 1 before and after joining, viewed from the side. FIG. 2 is a plan view and a bottom view showing the upper and lower surfaces of the Shiguchi precast member shown in FIG. 1; FIG. 2 is a construction order diagram showing the procedure for joining the column precast member shown in FIG. 1 and the joint precast member. The perspective view which showed the pillar precast member and the joint part precast member before joining in 2nd Embodiment of this invention. FIG. 6 is a side view of the column precast member and the joint precast member shown in FIG. 5 , showing the configuration before and after joining, when viewed from the side. FIG. 6 is a plan view and a bottom view showing the upper and lower surfaces of the Shiguchi precast member shown in FIG. 5; FIG. 6 is a construction order diagram showing a procedure for joining the column precast member shown in FIG. 5 and the joint precast member.

[First embodiment]
Hereinafter, the structure of the first embodiment of the method for joining the pillar precast member, the joint precast member, and the joining process of the present invention will be described with reference to FIGS. 1 to 4.

As an example, FIG. 1 shows the upper part of a pillar precast member 10 having a substantially square cross section with a side of 1000 mm and a height of 6 m, and a joint precast member 20 that is placed on the top surface 10b of the pillar and is to be joined before joining. It shows the status of. FIG. 2(a) shows a side view corresponding to FIG. 1. As shown in both figures, 24 column main reinforcements 1 made of deformed steel bars (D32) that penetrate the joint precast member 20 protrude from the column top surface 10b, and the protruding length is equal to that of the joint precast member 20. It is set approximately 220 mm longer than the height (approximately 1400 mm). In this embodiment, in addition to the column main reinforcement through-holes 2 of the number of column main reinforcements that pass through the joint part, the joint precast member 20 is filled with one grout that passes through the column vertically in the same way as the column main reinforcement through-holes 2. A hole 3 is provided. Note that when the diameter of the column main reinforcement through hole is sufficiently larger than the main reinforcement diameter, the column main reinforcement through hole 2 can also serve as the grout filling hole 3.

As shown in FIGS. 1 and 2(a), a column-side widened portion 10a is formed at the upper end of the column precast member 10 to be joined to the lower end of the joint precast member 20. The column side widened portion 10a is widened by about 150 mm in height and 50 mm in width from the column side surface including a lower haunch of about 50 mm, and the cross-sectional dimension at the column top surface 10b is 1100 mm square. Further, on the concrete surface of the column top surface 10b, a column-side grout-filled recess 11 is formed with a width of 25 mm from the periphery of each side and a square shape in plan view with a depth of 6 mm.

On the other hand, as shown in FIGS. 1 and 2(a), the precast joint part member 20 has an outer peripheral surface covered with a closing plate 4 made of a steel plate, and an internal concrete 23 is placed in the space surrounded by the closing plate 4. It consists of a poured composite structure. In this embodiment, beam end portions 5 having a predetermined cross-sectional shape are welded to the four outer surfaces of the cover plate 4. Furthermore, a joint-side widened portion 20a is formed at the outer circumferential portion of the lower end of the member that is joined to the upper end of the column precast member 10. In this joint part side widened part 20a, the reinforced concrete part exposed from the lower end of the closing plate 4 of the joint part is widened in the width direction by about 75 mm in height and 50 mm in width from the cross section of the joint part, and the lower end of the joint part is widened in the width direction. is 1100mm square. In addition, as shown in FIG. 3(b), the inner concrete lower surface 23a of this joint part is filled with grout on the joint part side in a square shape in plan view with a depth of 6 mm, ensuring a peripheral width of 25 mm on each side. A recess 21 is formed.

Here, a method for joining the pillar precast member 10 and the joint precast member 20 described above will be explained with reference to FIGS. 4(a) to 4(c). First, the column precast member 10 is erected at a predetermined erection position, and then, as shown in FIG. A backup material 15 as an elastic sealing material is attached so that the partitioned area has a substantially square shape that ensures a columnar cross section. The backup material 15 is a square rod made of EVA resin and has a square cross section with a thickness of about 40 mm and a width of about 20 mm, and is a flexible synthetic resin member that can be elastically deformed with loading. The backup material 15 is preferably attached to the concrete surface using an adhesive tape (not shown) that has been applied to one surface of the backup material 15 in advance. Furthermore, a plurality of spacers 16 having a height of 20 mm are installed on the column side grout filling recess 11 (FIG. 4(b)). This spacer 16 is preferably made of a member having rigidity and strength that does not deform even under the weight of the joint precast member 20. For example, a ready-made spacer 16 made of mortar, metal, synthetic resin, or the like can be used. In this embodiment, the backup material 15 is elastically deformed until the placed joint precast member 20 is placed on the spacer 16, so that the joint precast member 20 and the column precast member 10 face each other, and the backup material 15 A grout filling space 30 with a height of 20 mm and which is laterally partitioned is formed. This grout filling space 30 is filled with grout G flowing down from the grout filling hole, and the grout filling space 30 is filled with grout. The lower surface is integrally joined.

As the grout G to be filled, a premix type high-strength non-shrinkage mortar whose specific gravity is smaller than the concrete specific gravity of the joint precast member 20 is used. In this embodiment, the specific gravity of the joint precast member 20 is 24 kN/m ³ , while the specific gravity of the grout G is set to 21 kN/m ³ . In this way, by setting the specific gravity of the grout G to be lower than the specific gravity of the joint precast member 20 placed on top, the difference in specific gravity causes the joint precast member 20 located on the filled grout G to lift (lift up). ) can be prevented from occurring. Furthermore, since the grout G has high fluidity with a table flow value of about 300 mm, the grout filling space 30 can be filled by simply pouring the grout G from the top side of the joint precast member 20 through the grout filling hole (not shown). Ensures that every corner is filled. As the filling progresses further, the grout G rises inside each column main reinforcement through hole 2 and overflows from the upper end of each column main reinforcement through hole 2. By visually checking the filling state from the upper end of each through hole, it can be confirmed that all the main column reinforcement through holes 2 in the grout filling space 30 and the joint precast member 20 are filled with grout G.

[Second embodiment]
Hereinafter, the structure and a series of joining steps of a second embodiment of the method for joining the column precast member 10 and the joint precast member 20 of the present invention will be described with reference to FIGS. 5 to 8.

FIG. 5 shows the upper part of a precast reinforced concrete column (column precast member 10) having almost the same shape as the first embodiment (approximately square cross section of 960 mm on a side, column height 6 m) and the column top surface 10b in the second embodiment. It shows the joint part precast member 20 placed on and joined to the joint part precast member 20. In this embodiment, as in the first embodiment, 24 column main reinforcements 1 of deformed steel bars (D32) that penetrate the joint precast member 20 from the column top surface 10b protrude, and the joint precast member 20 has a joint. In addition to the number of column main reinforcement through-holes 2 that penetrate through the interior of the section, one grout filling hole 3 that penetrates the column in the vertical direction is provided similarly to the column main reinforcement through-hole 2 .

As shown in FIGS. 5 and 6(a), a column-side widened portion 10a is formed at the upper end of the column precast member 10 to be joined to the lower end of the joint precast member 20. As shown in FIGS. This column-side widened portion 10a is wider than the column cross section by about 120 mm in height and 20 mm in width, and the column concrete upper surface 10b is 1000 mm square. The column top surface 10b is a smooth surface unlike the first embodiment (FIG. 5).

On the other hand, the outer surface of the joint precast member 20 from the flange attachment position on the beam to the vicinity of the joint surface with the top end of the column is covered by a joint closing plate 4 (9 mm thick steel plate as an example) having a side of 1000 mm. . The internal concrete 23 in the joint precast member 20 is cast so that the lower end 4a of the closing plate 4 protrudes from the lower surface 23a of the internal concrete 23 by 20 mm. In this embodiment as well, beam end portions 5 having a predetermined cross-sectional shape are welded to the four outer surfaces of the cover plate 4.

In this embodiment, a clearance portion with a height of 20 mm formed between the lower surface 23a of the internal concrete 23 and the concrete upper surface 10b of the column precast member 10 functions as the grout filling space 35. Therefore, in the second embodiment, as shown in each figure, a large widened part that corresponds to the closing part side widened part 20a of the first embodiment is not provided.

Here, a method for joining the column precast member 10 and the joint precast member 20 of the second embodiment will be described with reference to FIGS. 8(a) to 8(c). Since the construction procedure is almost the same as that of the first embodiment, only points unique to the second embodiment will be described. After the pillar precast member 10 is erected at a predetermined erection position, as shown in FIG. The backup material 15 is pasted along the inner circumferential surface of the lower end 4a of the closing plate 4 of the joint precast member 20. Further, the joint precast member 20 is placed so that the lower end 4a of the closing plate 4 of the joint precast member 20 rests on the edge of the pillar precast member 10 (FIG. 8(b)). At this time, the backup material 15 is elastically deformed by the weight of the joint precast member 20 and comes into close contact with the joint precast member 20 and the pillar precast member 10, filling the grout filling space that is laterally partitioned by the backup material 15. 35 is formed. Next, the grout filling space 35 is filled with grout G from the grout filling hole (not shown), so that the grout filling space 35 is filled with grout G, and as the grout G solidifies, the concrete upper surface of the column precast member 10 is 10b and the lower surface 23a of the internal concrete 23 of the joint precast member 20 are integrally joined (FIG. 8(c)).

In this embodiment as well, the grout G to be filled has a specific gravity lower than the concrete specific gravity of the joint precast member 20 and has high fluidity. Therefore, simply by pouring the grout G from the upper surface side of the joint precast member 20, the grout filling space 35 is completely filled, and the grout G rises inside each column main reinforcement through-hole 2 to fill each column main reinforcement. The grout G is filled from the upper end of the through hole 2, and the state of filling of each part of the grout G can be visually confirmed.

In another embodiment, the precast column member is placed on the column precast member via a spacer, and while a grout filling space of a predetermined height is secured, the upper end of the column precast member is The weir plate may be placed so as to cover the gap between the grout filling space and the grout filling space. In this case, the weir plate can prevent the grout G from leaking out of the grout filling space, but a backup material may also be used to cover the sides of the grout filling space to improve sealing.

Note that the dimensions of each member described above are merely examples, and it goes without saying that various dimensions and numerical values can be set depending on the desired joint structure. Furthermore, the present invention is not limited to the embodiments described above, and various changes can be made within the scope of each claim. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included within the technical scope of the present invention.

1 Column main reinforcement 2 Column main reinforcement through hole 3 Grout filling hole 4 Closure plate 5 Beam end 10 Column precast member 10a Column side widening part 11 Column side grout filling recess 15 Backup material (elastic sealing material)
16 Spacer 20 Joint precast member 20a Joint widened part 21 Joint side grout filling recess 23 Internal concrete 30, 35 Grout filling space

Claims (7)

In a method for joining a column precast member having a plurality of column main reinforcements protruding from the upper surface of the column concrete and a joint part precast member having a through hole for holding the column main reinforcements,
While holding the main column reinforcement in the through hole so that a grout-filled space whose side surfaces are partitioned by a sealing material is formed between the upper surface of the column precast member and the lower surface of the joint precast member, placing the joint part precast member on the pillar precast member,
Filling the grout filling space through the through hole with grout having a specific gravity lower than the specific gravity of the joint precast member,
A method for joining a column precast member and a joint precast member, comprising integrally joining the pillar precast member and the joint precast member. The grout filling space is
Widthwise widened portions are provided on the upper end side of the column precast member and the lower end side of the joint precast member, and are formed on at least one of the upper surface of the column precast member and the lower surface of the joint precast member. a grout-filled recess, and the sealing material attached to ensure a column cross section of the column precast member;
2. The method for joining a column precast member and a joint precast member according to claim 1, wherein the column precast member and the joint precast member are partitioned by. The grout filling space is
a sealing material attached along the upper surface of the pillar precast member, the lower surface of the joint precast member, and the inner circumferential surface of the lower end of a closure plate protruding from the lower surface of the joint precast member;
2. The method for joining a column precast member and a joint precast member according to claim 1, wherein the column precast member and the joint precast member are partitioned by. The sealing material is elastically deformed when the joint precast member is placed on the pillar precast member, and comes into close contact with the pillar precast member and the joint precast member to fill the grout filling space. 4. The method of joining a pillar precast member and a joint precast member according to claim 2 or 3, wherein the elastic sealing material is used to partition the side surfaces. The column precast member and the joint according to claim 1, wherein the sealing material is a formwork member that is held on the outer peripheral surface of the column precast member or the joint precast member and partitions a side surface of the grout filling space. Method for joining precast members. 2. The method of joining a pillar precast member and a joint precast member according to claim 1, wherein the joint precast member has a grout filling hole arranged in parallel with the through hole. The grout is filled and flowed down from the upper end of the joint precast member through the through hole to fill the grout filling space, and the filling of the grout from the through hole in which the column main reinforcement is held is confirmed. 1. A method for joining a column precast member and a joint precast member according to 1.

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