JPH0765335B2 - Beam members made of reinforced concrete - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reinforced concrete beam member that is mainly used in a high-rise building or the like and that receives a high shearing force.

<Prior art> With the recent increase in the number of buildings, the stress generated in members, especially beam members, during earthquakes, etc. has become extremely large. Can no longer be secured. Also, if we try to arrange the shear reinforcement bars so that sufficient reinforcement can be secured, there will be problems in terms of construction, such as complicated reinforcement due to the thickening of the main bar, making it difficult to place concrete. Will occur.

Here, the following techniques have been proposed as techniques capable of addressing the above problems. This is one in which concrete is placed in a beam formwork having a substantially U-shaped cross section in which reinforcing bars are reinforced, and a beam member is configured as a whole including this beam formwork. Is (Japanese Patent Publication No. 45-3
5622, JP-A-50-88814, JP-A-58-50232, etc.). According to this structure, it is possible to secure a certain degree of shear reinforcement by using the beam form having a U-shaped cross section.

<Problems to be Solved by the Invention> However, in the above-mentioned proposal, a U-shaped beam formwork having an open upper end is used in consideration of concrete pouring at the site and the like. The frame itself has an open cross-section structure, and there is a problem in that it is insufficient in terms of strength.

Here, it is conceivable that the beam formwork has a closed cross section. However, in the case of such a configuration, there is a problem with the engagement between the beam member surrounded by the beam formwork and the floor material. It is desired to devise a beam member that can solve the problems of the strength of the beam member by closing the beam formwork with a closed cross section and the problem of the connection with the floor material all at once.

An object of the present invention is to provide a reinforced concrete beam member which can solve the problems of the strength of the beam member due to the closed cross section of the beam formwork and the problem of the connection with the floor material all at once.

<< Means for Solving the Problem >> The present invention is formed by surrounding the outer circumference of a reinforced concrete beam member to be joined with a floor material with a steel plate material having a hollow cylinder in a closed cross section, and the floor material of the beam member. And a shear key member is provided at the joint portion of the beam member and the plate member so as to penetrate therethrough and project outward from the inside of the beam member.

Further, in the above configuration, the steel plate material on the upper surface of the beam member is intermittently removed so as to correspond to a penetrating portion of the shear key member.

<Operation> To describe the operation of the present invention, an improvement in the shear strength of the beam member itself that receives a high shearing force is achieved by enclosing all or part of the outer periphery of the reinforced concrete beam member with a steel plate material to form a closed cross section. In addition, by providing a shear key member that projects outward from the inside of the beam member with a closed cross section in this way, a structure for engaging with the floor material is secured, and the beam member with a closed cross section is realized. You can do it.

<< Examples >> Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings.

A first embodiment of the present invention is shown in FIGS. It is installed at the upper end of the pillar structure (not shown) such as the already-installed pillar formwork or precast outer shell, or the pillar member such as the pillar member that has been demolded after the concrete has been cast to the lower end of the beam, and is joined to the floor material 6. The reinforced concrete beam member 1 is
The entire outer circumference is surrounded by the steel plate material 2. That is, flat plate-shaped steel plate materials 2 are combined to form a hollow cylindrical body 3 having a rectangular closed cross-section, and a beam main bar 4 is arranged inside the hollow of this closed cross-section, and concrete 5 is cast to form a beam. The member 1 is constructed.

Further, in particular, of the steel plate material 2 surrounding the outer periphery of the beam member 1,
Through holes are formed in the steel plate member 2 at a position where it is joined to the floor member 6 in the plate thickness direction, and the shear key is projected outward from the inside of the beam member 1 through these through holes. A member is provided. In this embodiment, this shear key member is composed of an inverted U-shaped reinforcing bar material 7, both ends 7a of which are embedded in concrete 5 which solidifies the beam member 1 through the through holes. The loop-shaped folded-back portion 7b is configured to project toward the floor material 6 side. Also this rebar material 7
Are arranged at intervals in the longitudinal direction of the beam member 1.

A floor member 6 is installed above the beam member 1 configured as described above. As shown in FIG. 1, the floor slab 8 is directly constructed on the upper surface of the beam member 1, and the reinforcing bar member 7 serving as the shear key member has its folded-back portion 7b embedded in the floor slab 8. There is. On the other hand, as shown in FIG. 2, the rib member slab 9, the omnier plate, the deck plate, etc. are erected on both edges 1a of the upper surface of the beam member 1, and the concrete 10 is placed on the slab 9. It was done.
In this case, the reinforcing bars 7 are located between the ribbed slabs 9 and the like, and are embedded in the concrete 10 that is placed from above while being sandwiched between the slabs 9 and the like.

A second embodiment of the invention is shown in FIGS. The structure of the beam member 1 is the same as that of the first embodiment, but in order to increase the integrated production of the slab and the beam, the part 12 of the main bar at the upper end of the beam is located outside the upper surface of the steel plate material 2 having a closed cross section. Will be arranged. In this embodiment, the shear key member is an inverted U-shaped reinforcing bar material 11 so as to also serve as a shear reinforcing bar for restraining the beam main bar 12 which is reinforced on the outside of the upper surface of the steel plate material 2 having a closed cross section. Both ends 11a, which are configured and particularly have anchor portions, are embedded in the concrete 5 that solidifies the beam member 1 through the through-holes, and the loop-shaped folded-back portion 11b is used for the flooring 6
It is configured to project to the side. Therefore, it is a shear key member, and the bonding strength between the reinforcing member 11 serving as shear reinforcement and the beam member 1 is enhanced. Further, a plurality of the reinforcing bars 11 are arranged at intervals in the longitudinal direction of the beam member 1 as in the above.

A floor member 6 is installed above the beam member 1 configured as described above. As shown in FIG. 3, the floor slab 8 is directly constructed on the upper surface of the beam member 1, and the reinforcing bar member 11 serving as the shear key member has its folded portion 11b hooked on the beam upper end main bar 12 in the floor slab 8. It is designed to be embedded in the floor slab 8. On the other hand, as shown in FIG. 4, a slab 9 with a rib, an omnier plate or a deck plate is erected on both edges 1a of the upper surface of the beam member 1, and concrete 10 is laid on the bridge.
It is constructed by placing. in this case,
The reinforcing bars 11 are positioned between the ribbed slabs 9 and the like, and are sandwiched between the slabs 9 and the like and are embedded in the concrete 10 that is hung on the beam upper end main bars 12 and cast from above. With such a configuration, the joint strength between the beam structure and the floor structure can be further improved.

FIG. 5 shows a third embodiment of the present invention. The structure of the beam member 1 is the same as that of the first embodiment.
In particular, among the steel plate materials 2 surrounding the outer circumference of the beam member 1, the steel plate material 2 at the side surface position which is joined to the floor material 6 in the horizontal direction is formed with a through hole penetrating this in the plate thickness direction. A shear key member is provided so as to project outward from the inside of the beam member 1 through the through hole. In this embodiment, this shear key member is composed of a linear reinforcing bar material 13, and its central portion 13
a is inserted and embedded below the main beam 4 of the concrete 5 which solidifies the beam member 1, and both ends 13b are horizontally projected to the floor 6 side. Therefore, the arrangement of the shear key member is simplified and the workability is improved. Further, a plurality of the reinforcing bars 13 are arranged at intervals in the longitudinal direction of the beam member 1 as described above.

A floor slab 8 is provided above the beam member 1 configured as described above.
Will be constructed. In FIG. 5, the floor slab 8 is directly installed on the upper surface of the beam member 1 with a slight overlap in the depth direction of the beam member 1, and the reinforcing bar member 13 serving as the shear key member has both ends thereof. The part 13b is embedded in the floor slab 8.

Next, a method for manufacturing the reinforced concrete beam member 1 of the present invention will be described.

As shown in FIG. 6, one of the open ends 3a and 3b of the hollow cylindrical body 3 formed by combining the steel plate materials 2 so as to surround the outer periphery of the beam member 1 is attached to one end 3a. Plate or formwork that closes to prevent pouring concrete 15
And the hollow cylindrical body 3 is installed upright with the mold frame 15 side facing downward so that the open other end 3b faces upward. At this time, the reinforcing bars 7, 11 and 13 serving as the shear key members are inserted into the hollow cylindrical body 3 through the through holes and fixed by welding 16 or the like. Then, the beam main bars 4 are arranged inside the hollow cylindrical body 3, and then concrete 5 is cast from above to manufacture the beam member 1.

Although the one shown in FIGS. 1 to 6 is a precast reinforced concrete beam member, the present invention can be applied to a cast-in-place beam member by configuring as shown in FIG. it can. In the embodiment shown in FIG. 7, the upper surface of the steel sheet material in the above embodiment is intermittently removed to partially open the upper surface, and a beam bar is arranged inside the steel sheet material 2 and an inverted U-shape is formed. -Shaped sheer key member 7 is projected upward from the above-mentioned opening to engage with the reinforcing bar of the floor, and concrete is placed inside the steel plate material 2 at the same time as the floor concrete so as to be integrally joined to the floor material. be able to. It should be noted that the above-mentioned "to intermittently remove the upper surface of the steel sheet material to partially open the upper surface" means that a portion of the upper surface of the steel sheet material having a U-shaped cross section that does not protrude from the shear key member is closed with a steel sheet at predetermined intervals. This is a concept including the case of welding with.

As explained above, by enclosing the outer periphery of the reinforced concrete beam member 1 with the steel plate material 2 to form a wholly or partially closed cross section, it is possible to improve the shear strength of the beam member 1 itself that receives a high shearing force. At the same time, by providing the reinforcing bars 7, 11 and 13 projecting outward from the inside of the beam member 1 having the closed cross section as described above, an engagement structure with the floor material 6 is secured,
It is possible to realize the adoption of the beam member 1 having a closed cross section.

<< Effects of the Invention >> In short, according to the present invention, the following excellent effects are exhibited.

By enclosing the outer circumference of the reinforced concrete beam member with a steel plate material to form a wholly or partially closed cross-section, it is possible to achieve an improvement in the shear strength of the beam member itself that receives high shearing force, and at the same time By providing the shear key member that protrudes outward from the inside of the beam member having a cross section, it is possible to secure an engagement structure with the floor material and to adopt a beam member having a closed cross section.

[Brief description of drawings]

1 and 2 are front sectional views showing a first embodiment of the present invention, FIGS. 3 and 4 are front sectional views showing a second embodiment of the present invention, and FIG. 5 is a front sectional view of the present invention. 3 is a front sectional view showing a third embodiment, FIG. 6 is a view for explaining a method for manufacturing a reinforced concrete beam member according to the present invention, and FIG. 7 is a perspective view showing another embodiment of the present invention. 1 …… Reinforced concrete beam member 2 …… Steel plate material 6 …… Floor material 7,11,13 …… Shear key member (rebar material)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Nagahara 4-640 Shimoseido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd. (56) Reference JP-A-58-83751 (JP, A)

Claims (2)

[Claims] 1. A reinforced concrete beam member to be joined to a floor member is formed by surrounding the outer periphery with a steel plate member having a hollow cylindrical shape with a closed cross section, and the steel plate is joined to the floor member at the joint part of the beam member. A beam member made of reinforced concrete, characterized in that a shear key member is provided by penetrating a material and projecting outward from the inside of the beam member. 2. The reinforced concrete beam member according to claim 1, wherein the steel plate material on the upper surface of the beam member is intermittently removed so as to correspond to a penetrating portion of the shear key member.