JPH078673Y2 - Composite beam structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a composite beam structure in a floor structure on the top floor of a steel building.

(Prior Art and Problems Thereof) In recent years, composite beam structures of steel-framed buildings have become widespread in response to the demands of the times such as weight reduction of steel frames, long span of beams, and reduction of beam strain.

However, in such a steel structure, when a horizontal load such as an earthquake is applied, a large in-plane stress is generated in the floor slab at the end of the composite beam, but such in-plane stress is balanced on the top floor. In reality, it is difficult to design composite beams on the top floor because there is no place to take reaction force.

On the other hand, on the general floor, the pillars themselves act as the ones that take such a reaction force, so there is no particular problem (see Fig. 4).

(Problem of the Invention) In view of the drawbacks of the conventional method, an object of the present invention is to provide a composite beam structure capable of receiving in-plane stress of the floor slab at the end of the composite beam on the uppermost floor.

(Means for Solving the Problems) The present invention has been made paying attention to the fact that it is indispensable to form a reaction force block that receives in-plane stress of the floor slab in order to make the uppermost beam a composite beam. Steel beams (2)
The H-section steel 31 having a length smaller than the thickness of the floor slab is installed and fixed on the upper surface of the steel column (1) to which is connected, with the length direction thereof being the vertical direction, and the H-section steel 31 is covered with concrete. The reaction block (3) that receives the in-plane stress of the floor slab is formed by continuous casting with the concrete of the floor structure, while the concrete at the reaction block (3) part is on the upper surface of the steel column (1). H-shaped steel stud dowel 32 to prevent peeling
The main point is that it was installed within 31.

The composite beam structure of the present invention is shown in the following embodiment, which is a steel structure building structure in which RC floor structures are formed by reinforced concrete reinforcement and concrete is placed on the steel beams passed between the steel columns. Although it can be applied, it can also be applied to a steel building structure in which a deck plate is laid on a steel beam and concrete is placed to form a composite floor structure.

According to the present invention, since the reaction block that is continuously integrated with the floor slab structure is formed at the top of the steel column according to the present invention, the surface of the floor slab at the beam end under horizontal load such as an earthquake is formed. As a result of being able to receive internal stress by the reaction force block and effectively transmit it to the steel column, it is possible to adopt a composite beam structure even on the top floor.

Further, since such a reaction block can be formed by placing H-shaped steel on the upper surface of the steel column connected to the steel beam and placing concrete, the construction is easy.

(Example) Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 3 show a composite beam structure according to an embodiment of the present invention, which is an example applied to a steel frame building structure having an RC floor structure. As shown in FIGS. 1 and 2, in forming the floor structure of the uppermost floor, the steel beam (2)
The H-shaped steel 31 having a length smaller than the thickness L of the floor slab is installed on the upper surface of the shaped steel or column steel column (1) to which are connected in the vertical direction in the vertical direction and fixed by welding. Pillar (1)
A stud dowel 32 for preventing the concrete from peeling off is provided so as to project into the space in the H-shaped steel 31 on the upper surface of the.

Next, when reinforcing bars 21 and 22 are arranged and concrete W is placed as shown in FIG. 3 to construct an RC floor structure together with the reinforcing bars 21 and 22, a reaction force is applied to the upper surface of the steel column (1). The block (3) is formed integrally with the RC floor structure, and the reaction beam block (3) constitutes a composite beam structure that receives in-plane stress of the floor slab. Incidentally, 23 is a stud dowel on the beam (2).

Specifically, as shown in FIG. 3, the H-shaped steel 31 is set to be slightly lower than the reinforcing bar 21 of the floor slab so that the reinforcing bar 21 of the floor slab covers the H-shaped steel 31 and the reaction force is increased. Greatly effective in preventing concrete cracks at the block (3) position.

Further, it is desirable that the stud dowel 32 for preventing peeling is provided so as to project to the position of the reinforcing bar 21.

Therefore, the reaction block (3) continuously integrated with the floor slab structure is formed at the top of the steel column (1) to reduce the in-plane stress of the floor slab at the beam end at the time of horizontal load such as an earthquake. Since it is received at (3) and transmitted to the steel column (1), a composite beam structure can be adopted even on the top floor.

Further, this reaction force block (3) can be formed by placing the H-shaped steel 31 on the upper surface of the steel frame column (1) connected to the steel frame beam (2) and pouring the concrete W, so that it can be easily constructed. There is also.

Further, the H-shaped steel 31 is set slightly lower than the reinforcing bar 21 of the floor slab so that the reinforcing bar 21 of the floor slab covers the H-shaped steel 31 and the stud dowel 32 is projected to the position of the reinforcing bar 21. , The reaction block (3) to prevent cracking and peeling of concrete at the reaction block (3)
The strength and rigidity of are increased.

[Brief description of drawings]

FIG. 1 is a side view showing the structure of a composite beam according to the present invention before placing concrete, FIG. 2 is a view taken along the line AA of FIG. 1, and FIG. 3 is a composite beam structure after placing concrete. Side view,
FIG. 4 is a side view showing a floor slab structure of steel columns and steel beams other than the top floor. (1) …… Steel column, (2) …… Steel beam, 21,22 …… Reinforcing bar, (3) …… Reaction block, 31 …… H-shaped steel, 32 …… Stud dowel

Claims (1)

[Scope of utility model registration request] 1. Reinforcement bars 21 and 22 are laid on a steel beam (2) passed between steel columns (1) and concrete W is placed in the RC.
In a steel-framed building structure that forms a floor structure or lays a deck plate and casts concrete to form a composite floor structure, steel beams (2) for forming the floor structure of the uppermost floor are connected. The H-shaped steel 31 having a length smaller than the thickness of the floor slab is installed and fixed on the upper surface of the steel frame column (1) with the length direction being the vertical direction. While a reaction force block (3) is formed which is cast continuously with concrete and receives in-plane stress of the floor slab, the concrete at the reaction force block (3) portion is formed on the upper surface of the steel column (1). A composite beam structure characterized in that a stud dowel 32 for preventing peeling is attached inside the H-shaped steel 31.