Method for joining column precast members and joint precast members

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

Technical Field

[0001] The present invention relates to a method for joining a column precast member and a joint portion precast member that can integrally join a column member and a joint portion member made of precast reinforced concrete with a minimum amount of high-altitude work and work on a scaffold.

Background Art

[0002] Conventionally, as a joining method for integrally joining a column made of precast reinforced concrete (column precast member) and a joint portion member made of precast reinforced concrete (hereinafter simply referred to as precast), a predetermined clearance is provided on the column precast member, the joint portion precast member is placed thereon, and the clearance portion is filled with grout to integrate the joint portion. In this joining method, in order to cover the outer periphery of the clearance portion provided in the joint portion, it is used as a formwork by closing it with a square bar-shaped sealing material such as a crossbar (Patent Document 1), or a sealing fitting with a rubber pressure-bonding piece is combined to form a cross-shaped structure to cover the outer periphery of the precast member (Patent Document 2), and a method of filling the clearance portion of the joint portion with mortar is disclosed. In addition, a method using an elongated air tube as a sealing material has also been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technologies disclosed in Patent Documents 1 and 2, in order to install sealing material (formwork, etc.) on the entire outer circumference of the upper end of a precast column, it was necessary for workers to climb to the top of the column using aerial work platforms or scaffolding and perform work on the entire circumference of the column. In addition, it was necessary to provide a stable concrete work platform or the like in order to deploy and set up the aerial work platforms or scaffolding, and incidental work for installing these was also required.

[0005] 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 under a predetermined pressure from either the top (upper surface) or the bottom. In this case, the grout used may have a specific gravity equal to or greater than that of the joint precast member. In this case, it was necessary to firmly fix the precast joint member to prevent the upper part of the precast joint member from lifting up and shifting from its installation position due to the pressure of the grout filling.

[0006] Therefore, the object of the present invention is to solve the problems of the conventional technology described above and to provide a method for joining a precast column member and a precast joint member that enables the precast column and the joint member to be integrally fixed and joined with minimal work at height or on scaffolding. [Means for solving the problem]

[0007] The present invention relates to a joining method for a column precast member having multiple main reinforcing bars protruding from the upper surface of the column concrete and a joint precast member having through holes for holding the main reinforcing bars, wherein a widthwise widening portion is provided on the upper end side of the column precast member and the lower end side of the joint precast member, a grout-filled recess is formed on at least one of the upper surface of the column precast member and the lower surface of the joint precast member, and the column precast member is attached in such a way as to secure the column cross-section. sealedThe method is characterized by the following: the main reinforcement of the column is held within the through-hole, the joint precast member is placed on the column precast member, a grout-filled space is formed partitioned by the fastening material, grout having a specific gravity lower than that of the joint precast member is filled into the grout-filled space through the through-hole, and the column precast member and the joint precast member are integrally joined.

[0009] Preferably, the grout-filled space is partitioned by the upper surface of the column precast member, the lower surface of the joint precast member, and a sealing material attached along the inner circumferential surface of the lower end of the sealing plate protruding from the lower surface of the joint precast member.

[0010] Preferably, the sealing material is an elastic sealing material that elastically deforms when the joint precast member is placed on the column precast member, and adheres tightly to the column precast member and the joint precast member, thereby partitioning the side surface of the grout-filled space.

[0011] Preferably, 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 demarcates the side surface of the grout-filled space.

[0012] The precast member of the joint preferably has grout-filling holes arranged in parallel with the through-holes.

[0013] It is preferable to fill the grout space by filling it through the through-hole from the upper end of the precast member of the joint and to confirm that the grout is filling through the through-hole in which the main reinforcement of the column is held. [Brief explanation of the drawing]

[0014] [Figure 1] A perspective view showing the column precast member and the joint precast member before joining, in a first embodiment of the present invention, so as to show the grout-filled recess formed on the upper surface of the column. [Figure 2] Figure 1 shows a side view of the precast column member and precast joint member before joining, and a side view of the configuration after joining. [Figure 3] Figure 1 shows the top and bottom views of the precast joint member. [Figure 4] Figure 1 shows a construction sequence diagram illustrating the procedure for joining the column precast members and the joint precast members. [Figure 5] A perspective view showing the column precast member and the joint precast member before joining, in a second embodiment of the present invention. [Figure 6] Figure 5 shows a side view of the precast column member and precast joint member before joining, and a side view of the configuration after joining. [Figure 7] Figure 5 shows the top and bottom views of the precast joint member. [Figure 8] Figure 5 shows a construction sequence diagram illustrating the procedure for joining the column precast members and the joint precast members. [Modes for carrying out the invention]

[0015] [First Embodiment] The configuration of the first embodiment of the column precast member, joint precast member, and joining method of the present invention, and a series of joining steps thereof, will be described below with reference to Figures 1 to 4.

[0016] FIG. 1 shows, as an example, the state before joining between the upper part of a column precast member 10 with a substantially square cross-section having a side length of 1000 mm and a height of 6 m, and a joint precast member 20 placed and joined on the upper surface 10b of the column. FIG. 2(a) shows the side state corresponding to FIG. 1. As shown in both figures, 24 column main reinforcements 1 of deformed steel bars (D32) penetrating through the joint precast member 20 protrude from the upper surface 10b of the column, and the protruding length is set to be approximately 220 mm longer than the height of the joint precast member 20 (about 1400 mm). In this embodiment, in addition to the column main reinforcement through-holes 2 for the number of column main reinforcements penetrating through the inside of the joint portion in the joint precast member 20, one grout filling hole 3 penetrating in the vertical direction of the column is provided in the same manner as the column main reinforcement through-holes 2. When the diameter of the column main reinforcement through-hole is sufficiently larger than the diameter of the main reinforcement, the column main reinforcement through-hole 2 can also serve as the grout filling hole 3.

[0017] At the portion of the upper end of the column precast member 10 joined to the lower end of the joint precast member 20, as shown in FIGS. 1 and 2(a), a column side widened portion 10a is formed. This column side widened portion 10a is widened to a height of 150 mm and a width of about 50 mm including a lower haunch about 50 mm below the column side surface, and the cross-sectional dimension on the upper surface 10b of the column is 1100 mm square. Further, on the concrete surface of this upper surface 10b of the column, a column side grout filling recess 11 having a square shape in plan view with a depth of 6 mm is formed while securing a width of 25 mm from the periphery of each side.

[0018] On the other hand, as shown in FIGS. 1 and 2(a), the joint opening precast member 20 has a composite structure in which the outer peripheral surface is covered with the splicing plate 4 made of a steel plate, and the internal concrete 23 is placed in the space surrounded by the splicing plate 4. In the present embodiment, beam end portions 5 having a predetermined cross-sectional shape are welded and joined to the outer side surfaces of the four sides of the splicing plate 4. Further, a joint opening side widened portion 20a is formed at the outer peripheral portion of the lower end of the member joined to the upper end of the column precast member 10. This joint opening side widened portion 20a is widened in the width direction such that the reinforced concrete portion exposed from the lower end of the splicing plate 4 of the joint opening is about 75 mm in height and 50 mm in width from the joint opening cross section, and the lower end of the joint opening is 1100 mm square. Further, as shown in FIG. 3(b), a joint opening side grout filling recess 21 having a square shape in plan view with a depth of 6 mm is formed on the lower surface 23a of the internal concrete of this joint opening while securing a peripheral edge width of 25 mm on each side.

[0019] Here, the method of joining the column precast member 10 and the joint precast member 20 described above will be explained with reference to Figures 4(a) to (c). First, the column precast member 10 is erected at a predetermined installation position, and then, as shown in Figure 4(a), a backup material 15 as an elastic sealing material is attached along the peripheral edge 10c of the column-side grout-filled recess 11 on the upper surface of the column precast member 10, so that the area to be partitioned is approximately square, ensuring the column cross-section. This backup material 15 is a square bar made of EVA resin with a rectangular cross-section of approximately 40 mm in thickness and approximately 20 mm in width, and is a flexible synthetic resin member that can be elastically deformed when a load is applied. It is preferable to attach this backup material 15 to the concrete surface with adhesive tape (not shown) that has been pre-applied to one side of the backup material 15. Furthermore, several spacers 16 with a height of 20 mm are installed on the column-side grout-filled recess 11 (Figure 4(b)). Preferably, the spacer 16 is made of a material that has rigidity and strength so as not to deform under the weight of the joint precast member 20. For example, a pre-fabricated spacer 16 made of mortar, metal, or synthetic resin can be used. In this embodiment, the backup material 15 elastically deforms until the placed joint precast member 20 rests on the spacer 16, so that the joint precast member 20 and the column precast member 10 face each other, and a grout-filled space 30 with a height of 20 mm is formed, partitioned laterally by the backup material 15. Grout G flows down and fills into this grout-filled space 30 from the grout-filling hole, filling the grout-filled space 30, and as the grout solidifies thereafter, the upper surface of the column precast member 10 and the lower surface of the joint precast member 20 are integrally joined.

[0020] The grout G used for filling is a premixed type of high-strength, non-shrink mortar whose specific gravity is lower than that of the concrete in the precast joint member 20. In this embodiment, the specific gravity of the precast joint member 20 is 24 kN / m³. 3 In contrast, the specific gravity of grout G is 21 kN / m³ 3This is how it is set. By making the specific gravity of the grout G lower than the specific gravity of the precast joint member 20 placed on top, it is possible to prevent the precast joint member 20 located on the filled grout G from lifting (floating) due to the difference in specific gravity. In addition, since the grout G has high fluidity with a table flow value of about 300 mm, the grout G can be reliably filled to the corners of the grout-filled space 30 simply by pouring it in from the upper side of the precast joint member 20 through the grout filling holes (not shown). As the filling progresses further, the grout G rises through each column main reinforcement penetration hole 2 and overflows from the upper end of each column main reinforcement penetration hole 2. By visually confirming the overflow state from the upper end of each penetration hole, it can be confirmed that all column main reinforcement penetration holes 2 in the grout-filled space 30 and the precast joint member 20 are filled with grout G.

[0021] [Second Embodiment] The configuration and a series of joining steps of the second embodiment of the column precast member 10, joint precast member 20, and joining method of the present invention will be described below with reference to Figures 5 to 8.

[0022] Figure 5 shows, in the second embodiment, the upper part of a precast reinforced concrete column (column precast member 10) which is substantially the same shape as in the first embodiment (approximately square cross-section with sides of 960 mm, column height of 6 m), and a joint precast member 20 which is placed on and joined to the column upper surface 10b. In this embodiment as well, similar to the first embodiment, 24 column main reinforcement bars (D32) protrude from the column upper surface 10b and penetrate the joint precast member 20. In addition to column main reinforcement penetration holes 2 corresponding to the number of column main reinforcement bars that penetrate the joint part, the joint precast member 20 is provided with one grout filling hole 3 that penetrates in the vertical direction of the column, similar to the column main reinforcement penetration holes 2.

[0023] At the upper end of the precast column member 10, where it is joined to the lower end of the precast column member 20, a column-side widened section 10a is formed, as shown in Figures 5 and 6(a). This column-side widened section 10a is widened by approximately 120 mm in height and 20 mm in width from the column cross-section, and the upper surface 10b of the column concrete is 1000 mm square. Unlike the first embodiment, the upper surface 10b of the column is a smooth surface (Figure 5).

[0024] On the other hand, the precast joint member 20 is covered on its outer surface from the beam flange mounting position to the vicinity of the joint surface with the upper end of the column by a joint closing plate 4 (for example, a 9 mm thick steel plate) with sides of 1000 mm. The internal concrete 23 inside the precast joint member 20 is poured so that the lower end 4a of the closing plate 4 protrudes 20 mm from the lower surface 23a of the internal concrete 23. In this embodiment as well, beam end portions 5 with a predetermined cross-sectional shape are welded to the four outer surfaces of the closing plate 4.

[0025] In this embodiment, the 20 mm high clearance portion formed between the lower surface 23a of the internal concrete 23 and the upper concrete surface 10b of the column precast member 10 functions as a grout-filled space 35. Therefore, in the second embodiment, as shown in each figure, a large widened portion corresponding to the widened portion 20a on the joint side of the first embodiment is not provided.

[0026] Here, the method for joining the column precast member 10 and the joint precast member 20 of the second embodiment will be explained with reference to Figures 8(a) to (c). The construction procedure is almost the same as that of the first embodiment, so only the points specific to the second embodiment will be explained. After the column precast member 10 is erected in the predetermined erection position, as shown in Figure 8(a), a square bar-shaped backup material 15 made of EVA resin with a square cross-section of approximately 30 mm in thickness and approximately 10 mm in width is attached along the inner circumferential surface of the lower end 4a of the closing plate 4 of the joint precast member 20. Furthermore, 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 column precast member 10 (Figure 8(b)). At this time, the backup material 15 elastically deforms under the weight of the joint precast member 20 and adheres tightly to the joint precast member 20 and the column precast member 10, forming a grout-filled space 35 partitioned laterally by the backup material 15. Next, grout G flows down into the grout-filled space 35 from a grout-filling hole (not shown), filling the grout-filled space 35 with grout G. As the grout G solidifies, the concrete upper surface 10b of the column precast member 10 and the lower surface 23a of the internal concrete 23 of the joint precast member 20 are integrally joined (Figure 8(c)).

[0027] In this embodiment as well, the grout G used has a specific gravity lower than that of the concrete in the precast joint member 20, and is highly fluid. Therefore, simply pouring the grout G into the precast joint member 20 from the upper side completely fills the grout-filled space 35, and the grout G rises through each column main reinforcement penetration hole 2 and overflows from the upper end of each column main reinforcement penetration hole 2, allowing the filling state of the grout G in each part to be visually confirmed.

[0028] In another embodiment, a precast joint member may be placed on a precast column member via a spacer, and with a grout-filled space of a predetermined height secured, a formwork plate may be placed to cover the space between the upper end of the precast column member and the precast joint member, and the formwork plate may be supported by the precast column member and the precast joint member to partition the sides of the grout-filled space. In this case, the formwork plate can prevent the grout G from leaking out of the grout-filled space, but to improve airtightness, a backup material may also be used to cover the sides of the grout-filled space.

[0029] It should be noted that the dimensions of each component described above are illustrative examples, and various dimensions and values ​​will be set depending on the desired joint structure. Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of each claim. In other words, embodiments obtained by combining technical means that have been appropriately modified within the scope of the claims are also included in the technical scope of the present invention. [Explanation of Symbols]

[0030] 1 Column main reinforcement 2 Column main reinforcement through hole 3 Grout-filled holes 4. Covering plate 5 Beam end 10 Precast Column Members 10a Column-side widening section 11 Column-side grout-filled recess 15. Backup material (elastic encapsulant) 16 Spacers 20 Precast joint members 20a Widening section of the joint 21 Grout-filled recess on the joint side 23 Interior concrete 30,35 Grout-filled space

Claims

1. In a method for joining a precast column member, which has multiple main reinforcing bars protruding from the upper surface of the column concrete, to a precast joint member having through holes for holding the main reinforcing bars, The upper end side of the column precast member and the lower end side of the joint precast member are provided with widthwise widening portions, and the joint precast member is placed on the column precast member while holding the column main reinforcement within the through-hole, such that a grout-filled space is formed, partitioned by a grout-filled recess formed on at least one of the upper surface of the column precast member and the lower surface of the joint precast member, and a sealing material attached to secure the column cross-section of the column precast member. A grout with a specific gravity lower than that of the precast member of the joint is filled into the grout-filled space through the through-hole. A method for joining a precast column member and a precast joint member, characterized by integrally joining the precast column member and the precast joint member.

2. The aforementioned grout-filled space is The upper surface of the column precast member, the lower surface of the joint precast member, and the sealing material attached along the inner circumferential surface of the lower end of the closing plate protruding from the lower surface of the joint precast member, A method for joining a column precast member and a joint precast member according to claim 1, wherein the column is partitioned by a certain means.

3. The method for joining a column precast member and a joint precast member according to claim 1 or 2, wherein the sealing material is an elastic sealing material that elastically deforms when the joint precast member is placed on the column precast member, and adheres tightly to the column precast member and the joint precast member to partition the side surface of the grout-filled space.

4. The method for joining a column precast member and a joint precast member according to claim 1, wherein 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 demarcates the side surface of the grout-filled space.

5. The method for joining a column precast member and a joint precast member according to claim 1, wherein the joint precast member has grout-filling holes arranged in parallel with the through holes.

6. A method for joining a precast column member and a precast joint member according to claim 1, wherein the grout is filled and flowed down from the upper end of the precast joint member through the through hole to fill the grout-filled space, and the filling of the grout from the through hole in which the main column reinforcement is held is confirmed.

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