JPS6367345A - Pillar and beam connection part of reinforced concrete structural skeletal - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a column-beam joint of a building made of reinforced concrete or steel-framed reinforced concrete, and relates to a reinforced concrete that improves the adhesion performance of beam main reinforcement at this joint. Concerning column/beam joints in structural frames.

(Prior art) Conventionally, in the structurally important beam-to-beam joints of reinforced concrete structural frameworks, the main reinforcing bars of beams or columns, which have been conventionally arranged in a conventional manner, are subject to large cyclic loads during earthquakes. This causes deterioration of the adhesion performance between the reinforcing bars and concrete at the column-beam joints, and the main beam reinforcements are noticeably pulled out from the joints, which impairs the resilience characteristics of the entire building frame. At the same time, the restoring force characteristics of the frame at that time showed defects such as an extreme decrease in rigidity and a decrease in energy absorption capacity, which accelerated the building's unfavorable earthquake resistance.

Therefore, a horizontal haunch is provided on the beam to increase the anchoring length of the beam reinforcement, or the main beam reinforcement is welded to the steel plate within the joint. In addition, measures have been proposed to mechanically improve the fixation of reinforcing bars by using nuts, etc., but this has not been put into general use due to constraints in architectural planning and economical considerations.

(Problems to be Solved by the Invention) Improving the anchoring performance of the beam main reinforcement within the predetermined joint will improve the seismic safety of the reinforced concrete structure.

This is one of the prerequisites to be solved, especially before high-rise construction of reinforced concrete #I structures. High-rise reinforced concrete buildings are generally designed to maintain seismic safety through the building's ability to absorb seismic energy against seismic forces.

Therefore, the building was designed with the assumption that the beam would collapse.
In the event of a major earthquake, seismic energy is mainly absorbed by the plastic hinges that occur at the ends of the beams, so it is necessary for some TR sections to have sufficient deformability after the main reinforcement yields. For this purpose, the anchorage of the main beam reinforcement within the joint must be sufficient.

The present invention has been made in view of the above circumstances, and its purpose is to improve the adhesion performance between concrete and reinforcing bars in column-beam joints, and thereby to improve the earthquake resistance of the entire building.

(Means for Solving the Problems) In order to achieve the above object, the reinforced concrete structure T1 frame shear/beam joint according to the present invention is a main reinforcement of a beam that passes n through the column/beam joint of a reinforced concrete structure. , a sheath that is embedded in the column and receives the main reinforcement of the beam, and the section of the main reinforcement of the beam that corresponds to the column-beam joint passes through the sheath, and grout is injected into the sheath to receive the main reinforcement of the beam. It is fixed within the sheath.

(Function) According to the above configuration, the concrete around the main reinforcement of the beam in the column-beam joint is made of a material with higher strength than the concrete in the general part of the column, and the grout material is restrained by the sheath. Therefore, regarding the adhesion between the sheath and the surrounding concrete, the main through reinforcement of the beam moves integrally with the sheath surrounding it, and the surface area of the main through reinforcement of the beam, which is involved in adhesion to the surrounding concrete, is equivalent to the surface area of the sheath. Therefore, this surface area is significantly larger than the surface area of the main reinforcement of the beam, and deterioration of adhesion performance in this part is unlikely to occur.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the state of connection between the main reinforcing bars 1 and the sheath 2 of the beam. The length of the sheath 2 is equal to or slightly shorter than the horizontal width of the column-beam joint. The main reinforcement 1 is inserted into the hollow part of the sheath 2, and a grout material 3 is injected into the hollow part to firmly connect the main reinforcement 1 and the sheath 2. This is buried horizontally at the beam mounting position of the company, but as shown in Figure 2, the sheaths 2a and 2b are placed at the beam mounting position t of the pillar 4, and later inside these sheaths 2a and 2b. The main reinforcing bars 1 of the beam may be inserted through the holes and fixed with grouting material. That is, the sheath 2a of the shaft 4 constitutes a reinforcement arrangement with column main reinforcements 5 and transverse reinforcements 6, and receives the main reinforcement 1 of the beam at the joint position with the beam.

2b is buried horizontally, and the hollow holes in the sheaths 2a and 2b are in a state where they can penetrate in the axial direction within the column-beam joint.

Figure 3 shows a precast column 8 in which the joint between the column 4 and the beam 7 is integrated, and a stirrup 9 is installed internally at the joint between the column 4 and the beam 7, and the main reinforcement 5 and the main reinforcement 1 of the beam are connected to each other. Each welded joint,
Column/beam joints are reinforced. Since the sheath 2 is restrained by the stirrup 9, the main reinforcing bar 1 of the beam will not be pulled out together with the sheath 2 from the forward/beam joint, and the concrete at the joint will be less likely to crack.

Figures 4 and 5 show the construction of the building, and Figure 4 shows the pillar 4.
The main reinforcement 1 for the beam is inserted into the sheath 2 previously installed at the column-beam joint position, and the main reinforcement 1 for the beam is injected into the sheath 2 to fix the main reinforcement 1 for the beam. After that, the beam reinforcement work is carried out by suspending the central part of the beam with the reinforcing steel frame loosely assembled, and press-welding the end of the main beam reinforcement 10 and the end of the main reinforcement 1 of the beam on the side 4. It is something that can be done, and it is light-hearted. In addition, it is better to simply insert the main reinforcement 1 of the beam into the sheath 2 without injecting the grout material 3, and suspend the frame at the center of the beam. Since there is no pressure bonding between the main beam reinforcement 1 and the beam main reinforcement 10, it is possible to perform pressure welding between the beam main reinforcement 10 and the beam main reinforcement 10 at both ends of the beam main reinforcement 10. Grout is injected into the sheath 2 at the column-beam joint portion after the beam main reinforcement 10 is positioned at a predetermined position.

FIG. 5 shows a case of a precast column 8 in which a joint between a column and a beam is formed in advance. The central part of a beam made of a loosely assembled reinforcing frame is suspended, and the end of the main beam reinforcement 10 and the end of the main reinforcement 1 of the beam on the column 8 side are pressure welded. For this purpose, the beam main reinforcement 10 is separated in the middle, and this part is finally connected by a lap joint or a welded joint.

As described above, at the column-beam joint, the main through-beam reinforcement 1 is fixed in the sheath with grout, and its both end extensions are connected to the main beam WJ10, and the main through-beam reinforcement 1 is connected to the column-beam joint. Sufficient adhesion performance was obtained within the unit.

(Effects) As explained in detail above, according to the column-beam joint of a reinforced concrete structure frame according to the present invention, the main reinforcement of the beam that passes through the column-beam joint of the reinforced concrete structure and the beam at the joint The sheath is placed in the direction in which the main through reinforcement of the beam passes through the mouth, and the main through reinforcement of the beam is inserted into this sheath and fixed with grout, so the surface area of the sheath is large compared to the main through reinforcement of the beam. In conjunction with this, the main reinforcement of the beam is fixed with grout material restrained by the sheath.
Even if repeated shearing forces on a column-beam joint cause cracks in the joint, which significantly reduces the adhesion of reinforcing bars, these cracks are unlikely to extend to the grout, and the main reinforcement of the beam It is possible to prevent deterioration of adhesion between the sheath and the joints around the concrete over a long period of time.

If deterioration of the adhesion of the main reinforcement of the beam inside the joint is prevented in this way, there will be no decrease in slip from the joint after the yield of the main reinforcement of the beam at the end of the beam, so the rotational ability of the beam plastic hinge will not be impaired. , exhibiting behavior with high seismic energy absorption capacity,
In turn, this has the effect of increasing the earthquake resistance of the entire building.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the connection between the main reinforcement of the beam and the sheath, Figure 2 is a longitudinal sectional view showing the joint between the column and beam and the main reinforcement of the beam, and Figure 3 is the connection between the column and beam. Fig. 4 is an explanatory diagram of erecting a beam frame at the column-beam joint, and Fig. 5 is a longitudinal cross-sectional view showing a precast column with integrated parts. FIG.

Claims (1)

[Claims] It is equipped with a main through-beam reinforcement that penetrates the column-beam joint of a reinforced concrete structure, and a sheath that is embedded in the column and receives the main through-beam reinforcement, and the main through-beam reinforcement has a section that falls within the column-beam joint. A column-beam joint of a reinforced concrete structural frame, characterized in that a main reinforcement of the beam is fixed within the sheath by passing through the sheath and injecting grout into the sheath.