JP6888944B2 - Joining method and structure of dissimilar materials in composite beams - Google Patents

Description

The present invention relates to different materials in a composite beam, for example, a method and a joining structure of a reinforced concrete beam at a beam end and a steel beam at a center of the beam.

Conventionally, as shown in FIG. 6, the composite (structure) beam 11 having a reinforced concrete beam 12 at the end and a steel beam 13 at the center not only lengthens the RC beam but also shortens the construction period, for example. Therefore, the cost can be suppressed, and the piping duct 17 can be provided between the beam and the ceiling 16.

The bonding method of the reinforced concrete beam 12 and the steel beam 13 in such a composite beam 11, for example, the conventional example 1: There is a format to embed the steel beam to concrete beam, the prior art 2: instead of embedding steel beam to concrete beam, both There is a form in which the boundary portion of the concrete is joined via a metal boundary plate.

In the conventional example 2, all or a part of the main bar of the reinforced concrete beam is welded to the boundary plate. As known documents, an example in which a two-stage bar is welded (Patent Document 1) and an example in which the entire main bar is welded (Patent Document 2) are known.

In the example in which the two-step reinforcement is welded, as shown in FIGS. 7A and 7B, the one-step reinforcement 12a of the main reinforcement in the reinforced concrete beam 12 penetrates the boundary plate (extremely thick) 18b and is fixed. The two-step bar 12b is welded to the boundary plate. The main bar is connected by the mechanical joint 19 in consideration of restrictions on transporting the length of the main bar (for example, about 12 m) and precasting of the end RC. Further, since the end portion of the two-step bar 12b is to be welded, the boundary plate (extremely thick) 18b fixed to the steel beam 13 is welded in advance at a factory or the like.

Japanese Unexamined Patent Publication No. 2015-004168 Japanese Unexamined Patent Publication No. 2009-215748

However, in the above conventional example 2, it takes time to weld the main bar to the boundary plate, and the welding inspection has many confirmation inspection items in order to confirm the welding accuracy such as bending and tipping and the assurance of welding quality. Therefore, there is a problem that it takes time and effort.

Further, as shown in FIG. 8, since the position of the flange 13a of the steel frame beam 13 and the position of the two-step streaks are matched, a height difference α from the position of the deck plate for forming the slab 14 is generated. .. Therefore, in order to match the slab level, a raised steel frame 13c for the deck plate is required. Therefore, there is a problem that it takes time and effort, the construction period becomes long, and the cost increases. The joining method and joining structure of different materials in the composite beam according to the present invention have been proposed to solve such a problem.

The gist for solving the above-mentioned problems of the method for joining different materials in the composite beam according to the present invention and achieving the object is that the steel beam on the center side of the beam and the reinforced concrete beam on the beam end side of the composite beam are different from each other. at the junction of member, the joint portions are integrated via the boundary plates of the steel beam, main reinforcement in the reinforced concrete beams, by penetrating the end portion of the main reinforcement in a through hole provided in the boundary plate, The threaded portion at the end thereof is fastened with a fixing nut, and the entire number of the main bars is fixed to the boundary plate with the nut. The main bar is composed of a one-step bar and a two-step bar. At the joint, the connection position of the upper flange of the steel beam connected to the boundary plate is the upper position of the two-step bar in the reinforced concrete beam , and the position of the upper end of the upper flange and the above. Sagamu between the position of the lower end of the upper slab of the steel beam rather, Ri thickness equal configuration der above the slab above the thick reinforced concrete beams of the slab of the steel beam, the nut of the boundary plate In fixing, nuts for positioning the boundary plate and introducing torque are screwed on both sides of the boundary plate .

Further, the main reinforcing bar includes a threaded reinforcing bar composed of a deformed reinforcing bar and a millimeter screw friction-welded to the deformed reinforcing bar.

The gist for solving the above-mentioned problems of the joint structure of different materials in the composite beam according to the present invention and achieving the object is that the steel beam on the center side of the beam and the reinforced concrete beam on the beam end side of the composite beam are different from each other. in the structure of the joint portion of the member, and a boundary plate of the steel beam of the through hole for the main reinforcement through is provided, its end is connected to a deformed reinforcing bar and said heterologous shaped reinforcing bars through the through hole of the threshold plate nut The main bar of the reinforced concrete beam , which is a reinforcing bar having a threaded portion to be fixed , the first and second step bars for the reinforced concrete beam composed of the main bar, and the total number of threaded portions of the main bar protruding from the boundary plate. The connection position of the upper flange of the steel beam connected to the boundary plate at the joint is the upper position of the two-step bar in the reinforced concrete beam. a is, and, the upper flange position of the upper end and the Sagamu rather the position of the lower end of the upper slab of steel beam, the thickness of the upper slab of the steel beam is above the reinforced concrete beams thickness and equal configuration der of the slab is, in the nut fixing of the boundary plate, on both sides sandwiching the boundary plate, a nut for positioning action and the torque introduction effect of the boundary plates are provided.

Further, the main reinforcing bar includes a threaded reinforcing bar composed of a deformed reinforcing bar and a millimeter screw friction-welded to the deformed reinforcing bar.

According to the joining method and joining structure of different materials in the composite beam of the present invention , long span can be achieved in reinforced concrete , and all joining between the main bar and the boundary plate is fixed with nuts, so that the workability of the joint is improved. , The construction period can be shortened. In addition, stress transmission at the joint becomes smooth.

Then, the main reinforcing bar is a threaded reinforcing bar composed of a deformed reinforcing bar and a millimeter screw friction-welded to the deformed reinforcing bar, so that the fit with the slab is further improved. Therefore, the conventional welding type requires a raised steel frame, but the present invention shortens the distance between the one-step bar of the main bar and the flange of the steel beam, so that the raised steel frame for receiving the slab is not required. Become. As a result, labor can be saved, workability is improved, and the construction period is shortened. Further, since the number of building materials is reduced and the installation work and the like are omitted, the cost can be reduced, which is an excellent effect. Further, by constructing the concrete beam at the end first, the joint of the main bar is not required, and the support work of the central steel beam is not required.

It is sectional drawing of one side which shows the joint structure of dissimilar materials in the composite beam which concerns on this invention. It is sectional drawing of one side which shows the other example of the joint structure of dissimilar materials in the composite beam of the present invention. It is sectional drawing of one side which shows still another Example of the joint structure of dissimilar materials in the composite beam which concerns on this invention. It is a cross-sectional view of the joint structure of dissimilar materials in the composite beam which concerns on this invention. It is sectional drawing which concerns on another Example of the joint structure of dissimilar materials in the composite beam which concerns on this invention. It is explanatory drawing which shows the advantage by making a reinforced concrete beam a composite beam by long span. It is a cross-sectional view (A) on one side showing a joint structure of different materials in a composite beam according to a conventional example, and a perspective view (B) of a boundary plate having a shear key or a stud and a steel beam. It is a cross-sectional view of the joint structure of dissimilar materials in the composite beam which concerns on the prior art.

As shown in FIG. 1, the joining structure of different materials in the composite beam according to the present invention is such that the boundary plate fixing method and the fixing structure of the main bar are all nut fixing.

As shown in FIG. 1, the joint structure of different materials in the composite beam according to the present invention includes a steel beam 13 which is a steel-framed beam 3 on the center side of the beam constituting the composite beam 1 and a reinforced concrete beam on the beam end side. In the structure of the joint portion of the dissimilar member with the reinforced concrete member 2a, which is No. 2, a through hole for penetrating the main bar (4,5) is provided, and there is a boundary plate 18 welded and joined to the steel beam at the factory.

The main bar is composed of a 1-step bar 4 and a 2-step bar 5 for a reinforced concrete beam. The main bars 4 and 5 are a reinforcing bar having a deformed reinforcing bar and a threaded portion whose end is connected to the deformed reinforcing bar and whose end portion penetrates through a through hole 18a (see FIG. 5B) of the boundary plate 18 and is fixed with a nut. It consists of. The reinforcing bar having this threaded portion is, for example, a threaded reinforcing bar in which the knots of the deformed steel bar are formed in a screw shape.

Further, it is composed of a threaded portion of the main bar protruding from the boundary plate 18, that is, a fixing nut 6 which is screwed and fastened to all the threaded portions of the threaded reinforcing bar.

The main reinforcing bars 4 and 5 have deformed reinforcing bars and threaded reinforcing bars 4a and 5a via a mechanical joint 19 for the purpose of transporting the reinforcing bars, precasting the RC portion, and fixing the nut to the boundary plate 18. You are connected. The mechanical joint 19 includes a known coupler joint, a threaded joint, a mortar-filled joint, a steel pipe crimping joint, and the like.

The main muscle is composed of a first-stage muscle 4 and a second-stage muscle 5. Then, as shown in FIG. 4, the connection position where the upper flange 13a of the H-shaped steel material 13 is connected to the boundary plate 18 at the joint portion of the dissimilar members is the upper position of the two-step bar 5 in the reinforced concrete beam 2. Therefore, there is no difference α from the position of the lower end portion of the slab 14, and a raised steel frame is unnecessary (difference from FIG. 8 of the conventional example).

In this way, by fixing all of the main bars 4 and 5 to the boundary plate 18 with nuts, the fit with the slab 14 is improved. In addition, the cost can be reduced by reducing the number of members.

Since all of the main bars 4 and 5 in the reinforced concrete beam 2 are fixed to the boundary plate 18 with nuts, welding work becomes unnecessary and workability is improved.

As shown in FIG. 2, as a second embodiment, the diameters of the reinforcing bars 4b and 5b having the threaded portions are adjusted so as to fit well with the slab 14 with respect to the threaded reinforcing bars 4a and 5a of the first embodiment. The diameter is smaller than the diameter of the deformed reinforcing bars of the main bars 4 and 5.

For example, millimeter screws 4b and 5b are used as the reinforcing bars having the threaded portion, and the deformed reinforcing bars of the main bar are joined by friction welding, and the main bars (1st step bar and 2 step bar) are used as threaded reinforcing bars. The diameter of the fixing nut 6a to be fastened to the other ends of the millimeter screws 4b and 5b is reduced. As a result, the vertical distance between the flange of the steel beam 13 and the first-stage bars 4 and 4b is reduced, and the fit with the slab 14 is improved.

As shown in FIGS. 1 to 5 (A), the positioning action of the boundary plate 18 and the steel frame beam in the reinforcing bars 4a, 5a, 4b, and 5b having the threaded portion on the beam end side with the boundary plate 18 interposed therebetween. The nut 8 is screwed on to introduce the torque of the nut from the side. With the nut 8, a predetermined torque can be introduced from the steel beam side when fastening the fixing nuts 6 and 6a.

Further, as shown in FIGS. 5A and 5B, in order to transmit the shearing force, the conventional shear key is used as a stiffening rib plate 9a, and the stiffening rib plate 9a is used as a stiffening rib plate 9 for reinforcing and supporting the stiffening rib plate 9a. , Along with the headed stud 10, it is provided on the beam end side of the boundary plate 18. By these improvements, the plate thickness of the boundary plate 18 can be reduced from, for example, 65 mm to 36 mm, and the plate thickness can be reduced.

The method of joining the joining structure of different materials in the composite beam according to the present invention as described above will be described. As shown in FIG. 1, after the reinforcement is arranged on the column 15 side, the H-shaped steel material 13 at the center of the beam is carried in between the columns 15 by a crane or the like and supported by the support work. A boundary plate 18 is welded and fixed to the end of the H-shaped steel material 13.

The necessary reinforcement of the two sections of the reinforced concrete beam is performed, and the first-stage reinforcement 4 and the second-stage reinforcement 5 of the main reinforcement are arranged. A mechanical joint 19 is provided in advance at the ends of the 1-step bar 4 and the 2-step bar 5. Then, the threaded reinforcing bars 4a and 5a are arranged to connect one end of each to the mechanical joint 19. The mechanical joint 19 adjusts the lengths of the first and second muscles, which are the main muscles.

As shown in FIGS. 1 to 5, a nut 8 can be provided on the end side of the boundary plate 18 so that torque can be introduced from the steel beam 13 side. Further, on the central portion side of the boundary plate 18, the nut 6 or the nut 6a is screwed and fastened to the fixing portion on the other end side of the threaded reinforcing bars 4a, 5a and the metric screws 4b, 5b. In this way, all the fixing portions of the main bars 4 and 5 are fixed to the boundary plate 18 with nuts.

On the reinforced concrete beam 2 side, a formwork for placing concrete is installed and supported by support work. Next, concrete is placed in the formwork. After that, a deck plate (not shown) is laid on the H-shaped steel material 13 on the central portion side, and concrete is cast on the deck plate (not shown) to complete the slab 14. As another embodiment, the reinforced concrete beam 2 can be precast by constructing it first. As a result, the joint 19 of the main bar is not required, and the support work of the central steel beam is also unnecessary.

In this way, all the connections of the composite beam 1 are fixed with nuts, and a joint structure with smooth stress transmission is obtained. It has been confirmed in tests that such a connection structure exhibits the same performance as the conventional type that uses both welded joints and nut joints.

As shown in FIG. 1, not only the joining of the deformed reinforcing bars and the threaded reinforcing bars 4a and 5a in the main bars 4 and 5, but also the joining of the deformed reinforcing bars and the millimeter screws 4b and 5b as shown in FIGS. By doing so, the fit with the slab is improved, and the workability is improved, such as eliminating the need for a raised steel frame.

Further, as shown in FIGS. 5A and 5B, the shear key 9a also used as the reinforcing steel rib plate, the reinforcing steel rib plate 9, and the headed stud 10 are reasonably arranged on the boundary plate 18 so as not to be overcrowded. However, by increasing the rigidity of the boundary plate 18, the thickness of the boundary plate 18, which was the conventional extra-thickness (65 to 85 mm), can be reduced (about 36 mm). As described above, in the joining of the composite beam 1 at the boundary plate 18, the joint is performed by fixing the nut and using a shear key that also serves as a stiffening rib plate, so that the workability can be improved and the plate thickness can be reduced.

The method and structure for joining dissimilar materials in a composite beam according to the present invention can be widely applied to a composite beam to be long-spanned.

1 Composite beam,
2 Reinforced concrete beams, 2a Reinforced concrete members,
3 Steel beam,
4 Main bar (1 step bar), 4a Threaded rebar,
4b small diameter millimeter screw,
5 main bars (2-step bars), 5a threaded reinforcing bars,
5b small diameter millimeter screw,
6 nuts, 6a nuts for screw fixing (small diameter),
7 Friction welding part,
8 nuts,
9 stiffening rib plate, 9a shear key that also serves as stiffening rib plate,
Stud with 10 heads,
11 Conventional composite beams,
12 reinforced concrete beams, 12a 1-step reinforcement,
12b 2-step muscle,
13 H-shaped steel material of steel beam, 13a flange,
13b web, 13c raised steel frame,
14 slab,
15 pillars,
16 ceiling,
17 Plumbing duct,
18 Boundary plate (thin plate), 18a through hole,
18b Boundary plate (extremely thick),
19 Mechanical fittings,
20 Welded part.

Claims (4)

At the joint of dissimilar members of the steel beam on the center side of the beam and the reinforced concrete beam on the beam end side that make up the composite beam
The joint portions are integrated via the boundary plates of the steel beam,
The main bar in the reinforced concrete beam penetrates the end portion of the main bar through a through hole provided in the boundary plate, and the screw portion held at the end portion is fastened with a fixing nut, and the entire number of the main bar is attached to the boundary plate. The nut is fixed and
The main muscle is composed of a 1-stage muscle and a 2-stage muscle.
At the joint, the connection position of the upper flange of the steel beam connected to the boundary plate is the upper position of the two-step bar in the reinforced concrete beam and the position of the upper end of the upper flange. the Sagamu the position above the lower end portion of the slab of steel beams rather, Ri thickness equal configuration der above the slab above the thick reinforced concrete beams of the slab of the steel beam,
A method for joining dissimilar materials in a composite beam in which nuts that perform a positioning action and a torque introducing action of the boundary plate are screwed on both sides of the boundary plate in fixing nuts of the boundary plate. The main rebar is a threaded rebar consisting of a deformed rebar and a millimeter screw that is friction-welded to the deformed rebar.
The method for joining dissimilar materials in a composite beam according to claim 1. In the structure of the joint between the steel frame beam on the center side of the beam and the reinforced concrete beam on the beam end side, which constitute the composite beam,
And a boundary plate of the steel beam of the main reinforcement through hole for penetration is provided,
The main reinforcing bar of the reinforced concrete beam , which is composed of a deformed reinforcing bar and a reinforcing bar having a threaded portion connected to the deformed reinforcing bar and whose end portion penetrates through a through hole of the boundary plate and is fixed with a nut.
The 1st and 2nd steps of the reinforced concrete beam composed of the main bars,
It consists of a fixing nut that is screwed and fastened to all the threaded portions of the main bar protruding from the boundary plate.
At the joint, the connection position of the upper flange of the steel beam connected to the boundary plate is the upper position of the two-step bar in the reinforced concrete beam and the position of the upper end of the upper flange. the Sagamu the position above the lower end portion of the slab of steel beams rather, Ri thickness equal configuration der above the slab above the thick reinforced concrete beams of the slab of the steel beam,
A joint structure of dissimilar materials in a composite beam in which nuts for positioning the boundary plate and introducing torque are provided on both sides of the boundary plate in fixing the nuts of the boundary plate. The main rebar is a threaded rebar consisting of a deformed rebar and a millimeter screw that is friction-welded to the deformed rebar.
The joint structure of dissimilar materials in the composite beam according to claim 3.

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