Connection Structure and Connection Method

Abstract

To provide a connection structure and a connection method that can securely transfer a tensile force and moment of a horizontal member of reinforced-concrete to a steel column and efficiently install it.SOLUTION: A connection structure 10 in which a slab 20 of reinforced-concrete is connected to a square steel pipe column 11 is provided with two layers of horizontal steel plates 15, 16 and a plurality of anchor reinforcements 30. The horizontal steel plates 15, 16 are provided spaced apart on an outer periphery of the square steel pipe column 11, and are embedded into the slab 20. The anchor reinforcements 30 are fixed to the square steel pipe column 11 through mechanical joints 17, 18 fixed to the horizontal steel plate 15, 16 in between two layers, and transfer a tensile force to slab reinforcements 21, 22 configuring the slab 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a connection structure and a connection method for connecting a horizontal member made of reinforced concrete such as a slab to a steel column.

Background Art

[0002] Normally, when providing a reinforced concrete slab on a steel column, a steel beam is provided on the steel column, and the reinforced concrete slab is arranged on this steel beam. Therefore, it was usually necessary to provide a steel beam between the steel column and the reinforced concrete slab. In addition, there are cases where a capital is provided on the steel column and a reinforced concrete slab is arranged.

[0003] Furthermore, a configuration in which the capital is eliminated and a slab is directly provided on the steel pipe column has been studied (see, for example, Patent Document 1). In this joining structure, after excavating the ground surface and placing the discarded concrete, a separation layer is applied thereon, the reinforcement for the flat slab and the concrete are placed on the separation layer, and the lower part is excavated after hardening. In this case, a plurality of column fixing bars that are welded to the constructed steel column and radially arranged, a plurality of steel rib plates provided on the outer peripheral surface of the steel column, and each hoop bar surrounding the periphery of the steel column are provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technique described in Patent Document 1, in order to reliably transmit the tensile force and moment of the reinforced concrete horizontal member to the steel column, a rigid rib plate, column fixing bars arranged radially, and a plurality of hoop bars surrounding the steel column are provided. Therefore, it takes time and effort for the reinforcement.

Means for Solving the Problems

[0006] The connection structure for solving the above problems is a connection structure in which a horizontal member of reinforced concrete is connected to a steel column, and includes a plate-like member that is fixed to the outer periphery of the steel column and embedded in the horizontal member, and a plurality of fixing bars that are fixed to the plate-like member and embedded at positions vertically spaced apart in the horizontal member to transmit tensile force to the reinforcing bars constituting the horizontal member.

[0007] Also, the connection method for solving the above problems is a connection method for connecting a horizontal member of reinforced concrete to a steel column. A plate-like member to be embedded in the horizontal member is provided on the outer periphery of the steel column. After the steel column is installed, fixing bars for transmitting tensile force to the reinforcing bars constituting the horizontal member are fixed to the plate-like member and embedded at positions vertically spaced apart in the horizontal member. After arranging the reinforcing bars on the surface side of the horizontal member rather than the plate-like member, concrete is placed to form the horizontal member.

Advantages of the Invention

[0008] According to the present invention, the tensile force and moment of the horizontal member of reinforced concrete can be reliably transmitted to the steel column, and the horizontal member can be efficiently installed on the steel column.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an embodiment in which a connection structure and a connection method for connecting a reinforced concrete horizontal member to a steel column are embodied will be described with reference to FIGS. 1 to 4. In the connection structure of this embodiment, a connection structure of a flat plate for connecting a slab as a horizontal member to a square steel pipe column as a steel column will be described.

[0011] As shown in FIG. 1, in the connection structure 10 of this embodiment, a slab 20 is connected to a square steel pipe column 11. The slab 20 has a structure that is vertically symmetric with respect to the central plane C1. Horizontal steel plates 15 and 16 as plate-like members extending in the horizontal direction are welded to the outer periphery of the square steel pipe column 11. The horizontal steel plates 15 and 16 are embedded in the slab 20 in a two-layer state arranged vertically with a gap therebetween, and are respectively located near the upper surface and the lower surface of the slab 20.

[0012] As shown in FIG. 2, the horizontal steel plates 15 and 16 are configured in a frame shape with a substantially square horizontal cross section. Reinforcing plates (webs) 19 are fixed to the horizontal steel plates 15 and 16 so as to be orthogonal to the horizontal steel plates 15 and 16. This reinforcing plate 19 is also welded to the square steel pipe column 11.

[0013] Furthermore, a plurality of through holes h1 are provided in the horizontal steel plates 15 and 16. Due to the notches in the horizontal steel plates 15 and 16, through holes h2 are provided at the corners of the square steel pipe column 11 and at the contact portions between the reinforcing plate 19 and the square steel pipe column 11. The through holes h1 and h2 are used for filling the concrete 25 of the slab 20.

[0014] As shown in FIG. 1, a plurality of mechanical joints 17 and 18 as fixing bar fixing portions are welded to the lower surface of the horizontal steel plate 15 and the upper surface (the opposing surfaces of the horizontal steel plates 15 and 16) of the horizontal steel plate 16, respectively.

[0015] As shown in FIG. 3, the plurality of mechanical joints 17, 18 are arranged to open on the side (outer side) opposite to the square steel pipe column 11. In the present embodiment, the mechanical joints 17, 18 are arranged at positions overlapping in the vertical direction. Thereby, the fixing bars 30 fixed to the mechanical joints 17, 18 are arranged at overlapping positions when viewed from above. Further, the ends of the mechanical joints 17, 18 are arranged so as not to protrude outside the outer peripheries of the horizontal steel plates 15, 16.

[0016] A fixing bar 30 is connected to each of the mechanical joints 17, 18. For the fixing bar 30, deformed reinforcing bars having a diameter larger than that of the slab bars 21, 22 constituting the slab 20 are used. This fixing bar 30 has a fixing length or more with an outer length L1 protruding from the horizontal steel plates 15, 16.

[0017] Furthermore, as shown in FIG. 1, the slab 20 is composed of slab bars 21, 22 and concrete 25 that constitute it. The slab bars 21, 22 are arranged in contact with the upper surface of the horizontal steel plate 15 and the lower surface of the horizontal steel plate 16, respectively. Then, the concrete 25 is placed with cover thicknesses T1, T2 with respect to the slab bars 21, 22. Thereby, the slab bars 21, 22, the horizontal steel plates 15, 16, the mechanical joints 17, 18, and the reinforcing plates 19 are embedded in the concrete 25. In the present embodiment, each mechanical joint 17, 18 is arranged between the slab bars 21, 22.

[0018] (Construction method of the connection structure 10) Next, a construction method of the connection structure 10 having the above-described configuration will be described. First, at a factory or the like, a plurality of mechanical joints 17, 18 are welded to the horizontal steel plates 15, 16. Then, at the construction site, at a height corresponding to the attachment position of the slab 20 on the square steel pipe column 11, the horizontal steel plates 15, 16 and the reinforcing plates 19 provided with the mechanical joints 17, 18 are welded. Thereby, a square steel pipe column 11 to which the horizontal steel plates 15, 16 and the reinforcing plates 19 provided with the mechanical joints 17, 18 are attached is formed.

[0019] Transport this square steel pipe column 11 to the site. In this case, the square steel pipe column 11 may be divided into a plurality of parts for transportation. And, at the site, install the square steel pipe column 11. Insert the fixing bars 30 into each of the mechanical joints 17, 18 of the square steel pipe column 11 to fix the fixing bars 30 to the square steel pipe column 11.

[0020] Next, arrange the slab bars 21 in a grid pattern on the upper surface of the horizontal steel plate 15, and arrange the slab bars 22 in a grid pattern under the horizontal steel plate 16. Then, place the concrete 25 using a formwork to form the slab 20.

[0021] (Function) In this embodiment, as shown in FIG. 4, since the slab bars 21, 22 are arranged close to the fixing bars 30 via the concrete 25, the tensile forces of the slab bars 21, 22 are transmitted to the fixing bars 30 by the adhesion and the transmission of the shear force of the concrete 25. And, the moment M1 of the slab 20 is transmitted to the square steel pipe column 11.

[0022] According to this embodiment, the following effects can be obtained. (1) In the connection structure 10 of this embodiment, it is fixed to the two-layer horizontal steel plates 15, 16 provided on the outer periphery of the square steel pipe column 11, and the fixing bars 30 having a fixing length are embedded in the slab 20. Thereby, the tensile forces of the slab bars 21, 22 of the slab 20 can be transmitted to the square steel pipe column 11 via the fixing bars 30. Also, since the horizontal steel plates 15, 16 are separated and arranged in the vicinity of the upper and lower surfaces of the slab 20, the fixing bars 30 can efficiently resist the moment M1. Also, since the fixing bars 30 are fixed to the horizontal steel plates 15, 16, the connection structure 10 can be efficiently constructed.

[0023] (2) In this embodiment, mechanical joints 17 and 18 are fixed to the horizontal steel plates 15 and 16, and the fixing bars 30 are fixed to the mechanical joints 17 and 18. Therefore, the fixing bars 30 can be fixed to the mechanical joints 17 and 18 welded to the square steel pipe column 11 in advance at the factory on-site. Therefore, from the factory to the site, when transporting the square steel pipe column 11, since the fixing bars 30 do not protrude, it is easy to handle. Also, the welding work at the site can be reduced.

[0024] (3) In this embodiment, a reinforcing plate 19 extending in the vertical direction perpendicular to the horizontal steel plates 15 and 16 is provided. Thereby, since the reinforcing plate 19 resists the shear force, damage due to punching shear can be suppressed.

[0025] (4) In this embodiment, slab bars 21 and 22 are respectively arranged outside the horizontal steel plate 15 to which the mechanical joints 17 and 18 are fixed on the facing surface side to form a slab 20. Therefore, since the slab bars 21 can be arranged on the horizontal steel plate 15 for steel bar placement, the working efficiency is good.

[0026] This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range. · In the above embodiment, the fixing bars 30 are arranged perpendicular to the horizontal steel plates 15 and 16. The arrangement of the fixing bars 30 is not limited to being perpendicular to the horizontal steel plates 15 and 16. For example, around the steel column, a plurality of fixing bars may be arranged radially from the center of the steel column. · In the above embodiment, two layers of horizontal steel plates 15 and 16 are provided on the square steel pipe column 11, and the mechanical joints 17 and 18 are fixed to each of the horizontal steel plates 15 and 16. The horizontal steel plates provided on the steel column are not limited to two upper and lower layers. For example, only one layer may be provided. Furthermore, the mechanical joint for fixing the fixing bars is not limited to being arranged on the opposing surfaces of the two-layer horizontal steel plates, and may be provided on the surfaces opposite to the opposing surfaces. For example, a plurality of fixing bars are fixed to the upper surfaces of the horizontal steel plate 15, the upper and lower surfaces of the horizontal steel plate 16. In this case, the fixing bars on the upper surface and the fixing bars on the lower surface are arranged at a plurality of positions spaced apart in the vertical direction. Specifically, the connection structure 60 shown in FIG. 5 may be used. In this case, a horizontal steel plate 65 is provided on the outer periphery of the square steel pipe column 61. Further, a plurality of mechanical joints 67 are fixed to the upper surface of the horizontal steel plate 65, and a plurality of mechanical joints 68 are fixed to the lower surface of the horizontal steel plate 65. Then, the ends of the fixing bars 80 are fixed to the mechanical joints 67 and 68, and slab bars 71 and 72 are arranged above and below the mechanical joints, respectively. Thereafter, the slab 70 is formed by placing concrete 75. Note that the fixing bars 80 can efficiently resist the moment M1 by being arranged at a position close to the surface of the slab 70 (a position farther from the central plane C2 of the slab 70).

[0027] · In the above embodiment, the fixing bars 30 have a length L1 equal to or greater than the fixing length within the slab 20, compared to the horizontal steel plates 15 and 16. The fixing bars 30 are not limited to having a length L1 equal to or greater than the fixing length, as long as they have an adhesive force capable of transmitting tensile force to the slab bars 21 and 22. For example, when a fixing plate is provided at the tip of the fixing bar 30 or when the tip is bent, it may be shorter than the fixing length of the straight-shaped fixing bar 30.

[0028] · In the above embodiment, mechanical joints 17 and 18 are respectively arranged between the slab bars 21 and 22, and the fixing bars 30 fixed to the mechanical joints 17 and 18 are made thicker than the slab bars 21 and 22. The sizes (thicknesses) and numbers of the slab bars 21 and 22 and the fixing bars 30 can be changed as appropriate. Also, when viewed from above, the slab bars 21 and 22 and the fixing bars 30 may be arranged so as to overlap.

[0029] ·In the above embodiment, the fixing bars 30 fixed to the horizontal steel plates 15 and 16 via the mechanical joints 17 and 18 are arranged at overlapping positions when viewed from above. The position and attachment method of the fixing bars 30 are not limited to this. For example, the fixing bar 30 fixed to the horizontal steel plate 15 and the fixing bar 30 fixed to the horizontal steel plate 16 may be arranged at positions shifted when viewed from above. Furthermore, the mechanical joint may be omitted, and the fixing bar 30 may be fixed by directly welding to the horizontal steel plates 15 and 16 or the like.

[0030] ·In the above embodiment, it was described as a connection structure in a flat plate structure in which the square steel pipe column 11 and the slab 20 are directly connected. The connection structure of the present invention is not limited to the case of being applied to a flat plate structure, and for example, it may be used in a flat slab structure or a connection structure between a steel column and a reinforced concrete beam. Here, the flat slab structure is a connection structure in which a reinforcing member is provided at a portion where the column and the slab are connected. Also in these connection structures, a horizontal member of reinforced concrete can be provided on the steel column.

[0031] ·In the above embodiment, the case where the square steel pipe column 11 is used as the steel column was described. The steel column is not limited to a square steel pipe column, and for example, it can be applied to a round steel pipe column, an SRC (Steel Reinforced Concrete) column, or a CFT (Concrete Filled Steel Tube) column.

[0032] Also, when applying to a counter-punching support column, it is difficult to use the square steel pipe column 11 with the horizontal steel plates 15 and 16 pre-welded in order to ensure accuracy. Therefore, in the case of a counter-punching support column, the horizontal steel plates 15 and 16 are provided on the outer periphery of the square steel pipe column 11 at the site according to the height of the slab.

[0033] Next, the technical idea that can be grasped from the above embodiment and alternative examples is added below. (a) The plate-like member is provided in two layers on the outer periphery of the steel column, The connection structure according to claim 1, wherein the fixing bars are arranged between the two layers. (b) The connection structure according to (a) above, wherein a reinforcing plate extending in a direction orthogonal to the plane in which the plate-like member extends is provided between the two layers in the plate-like member. (c) The connection structure according to (a) or (b) above, further provided with a plurality of fixing bar fixing portions fixed to the plate-like member between the two layers, wherein the fixing bars are fixed to the respective fixing bar fixing portions.

[0034] (d) The connection structure according to any one of claims 1 and (a) to (c) above, wherein the fixing bars are deformed reinforcing bars having a fixing length inside the horizontal member. (e) The connection structure according to any one of claims 1 and (a) to (d) above, wherein the fixing bars are arranged on the opposing surface side of the plate-like member, and the reinforcing bars constituting the horizontal member are arranged in a lattice pattern on the surface side opposite to the opposing surface of the plate-like member.

Description of Reference Numerals

[0035] C1, C2... central planes, h1, h2... through holes, L1... length, M1... moment, T1, T2... cover thickness, 10, 60... connection structures, 11, 61... square steel pipe columns, 15, 16, 65... horizontal steel plates, 17, 18, 67, 68... mechanical joints, 19... reinforcing plates, 20, 70... slabs, 21, 22, 71, 72... slab bars, 25, 75... concrete, 30, 80... fixing bars.

Claims

1. A connection structure in which a horizontal member of reinforced concrete is connected to a steel column, a plate-like member fixed to the outer periphery of the steel column and embedded in the horizontal member, and a plurality of fixing bars fixed to the plate-like member and embedded at positions vertically spaced apart in the horizontal member, wherein the fixing bars are arranged to have a length that has an adhesive force for transmitting a tensile force to the reinforcing bars in a state of being separated from the reinforcing bars constituting the horizontal member. The connection structure is characterized by this.

2. A mechanical joint is welded to the plate-like member, and the fixing bars are fixed to the mechanical joint. The connection structure according to claim 1 is characterized by this.

3. A connection method for connecting a horizontal member of reinforced concrete to a steel column, wherein a plate-like member to be embedded in the horizontal member is provided on the outer periphery of the steel column, after installing the steel column, a plurality of fixing bars arranged to have a length that has an adhesive force for transmitting a tensile force to the reinforcing bars in a state of being separated from the reinforcing bars constituting the horizontal member are fixed to the plate-like member in an arrangement where they are embedded at positions vertically spaced apart in the horizontal member, and after arranging the reinforcing bars in a state of being separated from the fixing bars on the surface side of the horizontal member rather than the plate-like member, concrete is placed to form the horizontal member. The connection method is characterized by this.

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