Method for constructing a column-beam frame and column structure

Abstract

To provide a method for constructing a column-beam frame that minimizes the area where floor concrete is poured, thereby reducing the impact of weather conditions during floor concrete pouring. [Solution] The method for constructing a column-beam frame is a method for constructing a column-beam frame 1 comprising PCa columns 20 on a slab 10 and steel beams 30 joined to the column heads of the PCa columns 20. This method for constructing a column-beam frame 1 includes the steps of: laying the deck plates 11 of the slab 10; pouring concrete on the deck plates 11 and directly below the PCa columns 20 to construct a portion of the slab 10 in advance as a joint concrete section 40; erecting the PCa columns 20 on the joint concrete section 40; attaching the steel beams 30 to the column heads of the PCa columns 20; and pouring concrete on the remaining portion of the deck plates 11 to complete the slab 10.

Description

Technical Field

[0001] The present invention relates to a construction method for a column-beam structure including column members and beam members, and a column structure, in which concrete is placed only directly below the column members instead of the entire bottom formwork to construct a joint concrete portion, and the column members are installed on this joint concrete portion.

Background Art

[0002] Conventionally, there has been a construction method for a structure in which a floor slab is constructed, and then precast concrete column members are erected, and precast concrete beam members are attached to the column heads of these column members (see Patent Documents 1 and 2). Patent Document 1 shows a construction method for a reinforced concrete structure. In this construction method, columns are erected on a slab floor surface, and precast large beams and conventional large beams are installed between the column heads of the columns. Patent Document 2 shows a construction method for a composite structure. In this construction method, RC columns are constructed on a slab floor surface, and semi-PC large beams and steel skeleton large beams are installed between the column heads of the RC columns.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a construction method for a column-beam structure and a column structure that can reduce the influence of weather during floor concrete placement by narrowing the placement range of floor concrete as much as possible.

Means for Solving the Problems

[0005] The inventors of this invention focused on the fact that, as a method for constructing a column-beam frame, concrete can be poured only directly beneath the column members, rather than across the entire bottom formwork, to create a joint concrete section, and the column members can be placed on this joint concrete section. This narrows the area where floor concrete is poured, reduces the influence of weather conditions during concrete pouring, and shortens the construction period, leading to the present invention. The first invention is a method for constructing a column-beam frame (e.g., a column-beam frame 1 described later) comprising a column member (e.g., a PCa column 20 described later) provided on a slab (e.g., a slab 10 described later), and a beam member (e.g., a steel beam 30 described later) joined to the column head of the column member, the method comprising: a step of erecting a bottom formwork (e.g., a deck plate 11 described later) for the slab (e.g., a step S1 described later), and pouring concrete on the bottom formwork at a position directly below the column member. The method is characterized by including the steps of: constructing a portion of the slab in advance as a joint concrete section (for example, the joint concrete section 40 described later) (for example, step S2 described later); erecting the column member on top of the joint concrete section (for example, step S3 described later); and completing the slab by attaching the beam member to the column head of the column member and pouring concrete into the remaining portion on the bottom formwork (for example, steps S4 and S5 described later).

[0006] If the column members are erected after the entire slab has been constructed, the area to be poured for the floor concrete becomes larger, which can lead to a longer concrete pouring time and make the process more susceptible to weather conditions. In contrast, according to this invention, only the portion of the slab directly beneath the column member is constructed in advance as a joint concrete section, and the column member is erected on top of this joint concrete section. Therefore, when concrete is poured only into the joint concrete section, the area to be poured is narrowed, shortening the concrete pouring time, thus reducing the impact of weather and shortening the construction period.

[0007] The method for constructing a column-beam frame according to the second invention is characterized in that, when attaching the beam members, a temporary scaffold (for example, temporary scaffold 2 described later) is attached to the column head of the column member, and the beam members are attached using the temporary scaffold.

[0008] According to this invention, a temporary scaffold is attached to the top of the column member, and workers climb onto this temporary scaffold to install the beam member. This eliminates the need to erect a worker's scaffold on top of the bottom formwork when installing the beam member, thus improving work efficiency.

[0009] The column structure of the third invention is a column structure in which a column member (for example, a PCa column 20 described later) is provided on a slab (for example, a slab 10 described later), wherein the slab is constructed by pouring concrete on a bottom formwork (for example, a deck plate 11 described later), and comprises a joint concrete section (for example, a joint concrete section 40 described later) located directly below the column member, and a post-cast concrete section other than the joint concrete section.

[0010] According to this invention, only the portion of the slab directly beneath the column member is constructed in advance as a joint concrete section, and the column member is erected on top of this joint concrete section. Therefore, when concrete is poured only into the joint concrete section, the area to be poured is narrowed, shortening the concrete pouring time, thus reducing the impact of weather conditions and shortening the construction period. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a method for constructing a column-beam frame and a column structure that can reduce the area over which floor concrete is poured, thereby reducing the influence of weather conditions during floor concrete pouring. [Brief explanation of the drawing]

[0012] [Figure 1] This is a side view of a column-beam frame constructed by a method for constructing a column-beam frame according to one embodiment of the present invention. [Figure 2]It is an enlarged view of the part surrounded by the broken line A of the column-beam structure in FIG. 1. [Figure 3] It is a side view of the joint concrete part constituting the column-beam structure. [Figure 4] It is a plan view of the joint concrete part. [Figure 5] It is a longitudinal sectional view of the column-beam structure. [Figure 6] It is a sectional view taken along the line B-B of the column-beam structure in FIG. 5. [Figure 7] It is an enlarged view of the part surrounded by the broken line C of the column-beam structure in FIG. 5. [Figure 8] It is a flowchart of the procedure for constructing the column-beam structure. [Figure 9] It is an explanatory drawing of the procedure for constructing the column-beam structure (Part 1, the situation where the formwork is built). [Figure 10] It is an explanatory drawing of the procedure for constructing the column-beam structure (Part 2, the situation where the PCa column is built). [Figure 11] It is an explanatory drawing of the procedure for constructing the column-beam structure (Part 3, the situation where the steel beam is built).

Mode for Carrying Out the Invention

[0013] The present invention is a method for constructing a column-beam structure and a column structure in which concrete is placed only directly below the column member instead of the entire bottom formwork to construct a joint concrete part, and a column member is installed on this joint concrete part. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a column-beam structure 1 constructed by the method for constructing a column-beam structure according to an embodiment of the present invention. [[ID=4I]]The column-beam structure 1 includes a slab 10 constructed on site, a precast concrete column (PCa column) 20 as a column member attached on the slab 10, and a steel beam 30 as a beam member joined to the column head of the PCa column 20. A temporary scaffold 2 for attaching the steel beam 30 is attached to the upper end of the PCa column 20. Further, the side surface of the PCa column 20 is supported from the deck plate 11 by the diagonal support 3.

[0014] Figure 2 is an enlarged view of the portion surrounded by the broken line A of the column-beam structure 1 in Figure 1. Figure 3 is a side view of the joint concrete part 40 that constitutes the column-beam structure 1. Figure 4 is a plan view of the joint concrete part 40. Figure 5 is a longitudinal sectional view of the column-beam structure 1. Figure 6 is a sectional view taken along the line B-B of the column-beam structure 1 in Figure 5. Figure 7 is an enlarged view of the portion surrounded by the broken line C of the column-beam structure 1 in Figure 5. The slab 10 includes a steel deck plate 11 as a bottom formwork, lower slab reinforcement bars 12 and upper slab reinforcement bars 13 arranged in a grid pattern on the deck plate 11, and a concrete body 14 formed by placing concrete on the deck plate 11 and incorporating the slab reinforcement bars 12 and 13.

[0015] At the position directly below the PCa column 20 in the slab 10, a joint concrete part 40, which is a part of the slab 10, is constructed. As shown in Figure 5, an anchor bolt 41 and a load-bearing member 42 are provided in the joint concrete part 40. The load-bearing member 42 includes a long nut 43 embedded in the joint concrete part 40 and a load-bearing bolt 44 screwed onto the long nut 43. The portion of the slab 10 other than the joint concrete part 40 is a post-cast concrete part 15.

[0016] As shown in Figure 5, the PCa column 20 includes column main reinforcement bars 21, hoop reinforcement bars (not shown) wound around the column main reinforcement bars 21, and a concrete body 22 incorporating the column main reinforcement bars 21 and the hoop reinforcement bars. A cylindrical sleeve 23 is embedded in the concrete body 22 of the PCa column 20, and the lower end of this sleeve 23 is exposed on the lower end surface of the concrete body 22, enabling the insertion of the anchor bolt 41. Also, the lower end of the column main reinforcement bars 21 is connected to the upper end of the sleeve 23, and the upper end of the column main reinforcement bars 21 protrudes upward from the upper end surface of the concrete body 22. The gap between the upper surface of the joint concrete part 40 and the lower surface of the PCa column 20, and the gap between the anchor bolt 41 and the sleeve 23 are filled with grout material 45.

[0017] As shown in Figure 5, a steel support portion 24 that protrudes upward is formed in the center of the upper surface of the concrete body 22 of the PCa column 20. The steel beam 30 comprises four H-shaped steel beams 32 that intersect each other at an intersection 31, and a cylindrical joint portion 33 that covers the intersection 31 of the H-shaped steel beams 32. The intersection 31 of the steel beam 30 rests on the steel support portion 24 of the PCa column 20, and the concrete body 22 of the PCa column 20 and the joint portion 33 of the steel beam 30 are connected by a steel support 50.

[0018] As shown in Figure 7, the steel support 50 is made by connecting two angle steels 51 and 52 with bolts 53. The lower angle steel 51 of the steel support 50 is temporarily fixed to the concrete body 22 of the PCa column 20 with bolts 54. The upper angle steel 52 of the steel support 50 is temporarily fixed to the joint 33 of the steel beam 30 with bolts 55.

[0019] The procedure for constructing the column-beam frame 1 will be explained below, referring to the flowchart in Figure 8. In step S1, the deck plate 11 is laid down as shown in Figure 9. In step S2, as shown in Figure 9, the joint concrete section 40, which will become part of the slab 10, is constructed in advance on the deck plate 11. In other words, first, slab reinforcement bars 12 and 13 are placed on the deck plate 11. Next, using the template 60, the anchor bolts 41 of the joint concrete section 40 are temporarily fixed to the slab reinforcement bars 12 and 13, and the long nuts 43 of the load-bearing member 42 are temporarily fixed to the slab reinforcement bars 12 and 13 or the anchor bolts 41. The template 60 is provided with multiple through holes 61, and the position of the anchor bolts 41 is determined by inserting the anchor bolts 41 through these through holes 61. Next, formwork 62 is erected at the side of the joint concrete section 40, and concrete is poured inside the area enclosed by the formwork 62.

[0020] In step S3, as shown in Figure 10, the PCa column 20 is erected on top of the joint concrete section 40. Specifically, first, the template 60 and formwork 62 are removed, and the load-bearing bolts 44 are rotated to adjust the height of the upper end surface of the load-bearing bolts 44. Also, the precast concrete columns 20 are temporarily placed in the temporary storage yard, and the temporary scaffolding 2 is attached to the upper end of these precast concrete columns 20. Next, the precast concrete column 20, which was temporarily placed on the ground surface, is lifted using a lifting machine (not shown) and placed on the load-bearing bolts 44 of the joint concrete section 40. At this time, the anchor bolts 41 are inserted into the sleeves 23 of the precast concrete column 20. To prevent the precast concrete column 20 from falling over, its sides are supported from the deck plate 11 by diagonal supports 3 (see Figure 1). Next, grout material 45 is filled into the gap between the upper surface of the joint concrete section 40 and the lower surface of the PCa column 20. At this time, the grout material 45 is also filled into the gap between the anchor bolt 41 and the sleeve 23.

[0021] In step S4, as shown in Figure 11, the steel beam 30 is attached to the top of the PCa column 20. Specifically, the steel beam 30 is lifted using a lifting machine (not shown), and workers climb onto the temporary scaffolding 2 to place the steel beam 30 on the steel support portion 24 of the PCa column 20. Next, the PCa column 20 and the steel beam 30 are connected with steel supports 50.

[0022] In step S5, concrete is poured onto the remaining portion of the deck plate 11 to construct the post-cast concrete section 15, completing the slab 10.

[0023] This embodiment provides the following effects. (1) Only the portion of the slab 10 directly beneath the PCa column 20 was constructed in advance as the joint concrete section 40, and the PCa column 20 was erected on top of this joint concrete section 40. Therefore, since concrete is poured only on the joint concrete section 40 and not on the entire slab 10, the area to which concrete is poured is narrowed. As a result, the concrete pouring time is shortened, the impact of weather is reduced, and the construction period can be shortened. (2) A temporary scaffolding 2 is attached to the top of the PCa column 20, and workers climb onto this temporary scaffolding 2 to install the steel beam 30. This eliminates the need to erect scaffolding for workers on the deck plate 11 when installing the steel beam 30, thus improving work efficiency.

[0024] Furthermore, the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included within the scope of the present invention. In the above embodiment, the deck plates 11 of the slab 10 were laid over the entire surface before the joint concrete section 40 was constructed. However, the invention is not limited to this, and the deck plates 11 in the portion that will become the later-cast concrete section 15 may be laid in a later construction. That is, initially, the deck plates 11 may be laid only in the portion that will become the joint concrete section 40, the joint concrete section 40 may be constructed, the PCa columns 20 may be erected, and the steel beams 30 may be attached, after which the deck plates 11 in the portion that will become the later-cast concrete section 15 may be laid.

[0025] Furthermore, in the above-described embodiment, the steel beam 30 was attached to the top of the PCa column 20 in step S4, and then the cast-in-place concrete section 15 was constructed in step S5. However, the process is not limited to this, and the work of attaching the steel beam 30 to the top of the PCa column 20 and the work of constructing the cast-in-place concrete section 15 may be performed simultaneously. Doing so would further shorten the construction period. [Explanation of symbols]

[0026] 1…Column and beam frame 2…Temporary scaffolding 3…Diagonal support 10...Slab 11...Deck plate (bottom formwork) 12...Lower slab reinforcement 13...Upper slab reinforcement 14...Concrete body 15...Post-cast concrete section 20...PCa column (column member) 21...Main reinforcement for column 22...Concrete body 23...Sleeve 24...Steel frame support 30...Steel beam (beam member) 31...Intersection 32...H-shaped steel 33...Joint 40... Joint concrete section 41... Anchor bolt 42... Load-bearing member 43...Long nut 44...Load-bearing bolt 45...Grout material 50...Steel frame support 51...Lower angle steel 52...Upper angle steel 53, 54, 55... Bolts 60...Template 61...Through hole 62...Formwork

Claims

1. A method for constructing a column-beam frame comprising a column member provided on a slab and a beam member joined to the column head of the column member, The process of laying the bottom formwork for the slab, The process involves pouring concrete on the bottom formwork and at a position directly below the column member to construct a portion of the slab in advance as a joint concrete section, The process of erecting the column member on top of the joint concrete section, A method for constructing a column-beam frame, characterized by including the steps of: attaching the beam member to the column head of the column member and pouring concrete into the remaining portion on the bottom formwork to complete the slab.

2. The method for constructing a column-beam frame according to claim 1, characterized in that when attaching the beam member, a temporary scaffold is attached to the column head of the column member, and the beam member is attached using the temporary scaffold.

3. A column structure in which column members are provided on a slab, The column structure is characterized in that the slab is constructed by pouring concrete on a bottom formwork and comprises a joint concrete section located directly below the column member and a post-cast concrete section other than the joint concrete section.

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