JP2617399B2 - Synthetic beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite beam for adding an RC structure to a steel structure in a building or civil engineering structure.

[0002]

2. Description of the Related Art In recent years, research has been conducted on structural members in which reinforcements are arranged in a portion surrounded by flanges and webs of an H-section steel, and concrete is cast therein to incorporate RC structures.

[0003] This structural member acts as an SRC member in the event of an earthquake, and in the event of a fire, the RC structure prevents the structure from collapsing. In particular, with respect to fracture, the initial rigidity, ultimate proof stress, and toughness ratio are improved by reinforcing the web of the H-section steel with concrete or the like.

[0004]

However, when such a structural member is used as a beam member, there is a problem in that the overall weight increases and the cost becomes high.

An object of the present invention is to provide a composite beam which can solve the above-mentioned disadvantages of the prior art and can reduce the weight and cost as a beam material.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a stiffener for vertically partitioning a portion surrounded by a flange and a web at boundaries between both ends and a center portion of an H-shaped steel beam and other portions. The main reinforcing bar and the portion surrounded by the flange and the web only at both ends and the central portion of the beam as a portion having a large bending stress against a long-term load and a short-term load in the axial direction of the H-shaped steel beam. The gist of the present invention is to arrange stirrups and cast concrete to incorporate a RC structure.

[0007]

According to the present invention, the stress generated in the beam is generally not constant in the direction of the shaft member.
Since the bending stress at both ends and the central part of the beam is large, and the bending stress at both ends of the beam during an earthquake is large, the structural type of the cross section of the beam is changed at places where the stress is large and where it is small. High SRC construction. In other words, stiffeners are provided at both ends and the center of the steel beam and other parts to clarify the boundaries, and the main and stirrups are arranged only at the ends and the center of the beam where the stress is large. The stiffener was used as a formwork and concrete was poured into the stiffener to incorporate the RC structure. At this time, since the reinforcing bars use not only the main bars but also the stirrups, the strength is sufficient, and since the stiffener is used as the mold, the work can be easily performed without the trouble of separately preparing the mold. And since other parts other than the part made into this SRC construction are S constructions which do not arrange reinforcing bars and cast concrete, it is possible to reduce the weight and cost of the beam material.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view showing an embodiment of a composite beam according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
It is a line sectional view. In the drawing, reference numeral 1 denotes a column, and 2 denotes a beam. The beam of the present invention is made of an H-shaped steel frame 3, but only partially in the direction of the shaft in a direction surrounded by a flange 3a and a web 3b. And stirrups 5 were arranged, and concrete 6 was cast to make the SRC structure 7 with a built-in RC structure. The other parts are the same as those of the S structure 8 without any addition.

As described above, the SRC structure 7 is formed at a portion where bending stress is large with respect to a long-term load and a short-term load, that is, at both ends and the center of the beam 2. In addition, SRC construction 7
A stiffener 9 that vertically partitions a portion surrounded by the flange 3a and the web 3b is provided at a boundary between the stiffener 9 and the S structure 8.

In this embodiment, the stirrups 5 constituting the SRC structure 7 are formed by using bent rebars. However, as another embodiment, parallel rebars may be used as shown in FIG. In either case, the stirrups 5 are welded at the ends or bent portions to the flanges 3a. However, when a bent rebar is used, the number of welding points is small.

FIGS. 5 to 12 show fixing examples of the main reinforcement 4 and the stiffener 9. As a first example, FIGS.
As shown in (1), a through hole is provided in the stiffener 9, and the end of the main bar 4 is formed into a screw structure, protruded through the through hole, and fastened with a nut 10.

As a second example, as shown in FIGS. 7 and 8, the ends of the main reinforcing bars 4 are butted and welded to the surface of the stiffener 9. In this case, the end of the main bar 4 is formed into a shape suitable for welding by beveling.

As a third example, as shown in FIGS. 9 and 10, a through hole is provided in the stiffener 9, and the end of the main bar 4 is projected through the through hole, so that the stiffener 9 and the main bar 4 are connected to the stiffener 9. Weld fillets on both sides of

As a fourth example, a horizontal rib 11 is provided on the stiffener 9 as shown in FIGS. 11 and 12, and the end of the main bar 4 is welded to the horizontal rib 11. In this case, the horizontal rib 11 also serves as a stiffener for the stiffener 9.

[0015]

As described above, the synthetic burrs of the present invention are:
The structural form of the cross section of the beam at the place where the stress is large and the place where the stress is small are changed, and the both ends and the center of the beam are separated by stiffeners from the other parts as the part where the stress is large. Because the stirrups with excellent stirrups are arranged and concrete is cast using the stiffener as a formwork, the RC structure is built into the SRC structure, and the other portions remain the S structure without reinforcing bars and concrete casting. Therefore, the weight and the cost of the beam material can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a composite beam according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a front view of a main part showing another embodiment.

FIG. 5 is a front view showing a first example of fixing between a main bar and a stiffener.

FIG. 6 is a sectional view taken along line CC of FIG. 5;

FIG. 7 is a front view showing a second example of fixing between a main bar and a stiffener.

FIG. 8 is a sectional view taken along line DD of FIG. 6;

FIG. 9 is a front view showing a third example of fixing the main streaks and the stiffener.

FIG. 10 is a sectional view taken along line EE of FIG. 9;

FIG. 11 is a front view showing a fourth example of fixing of a main bar and a stiffener.

FIG. 12 is a sectional view taken along line FF of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Column 2 ... Beam 3 ... H-shaped steel frame 3a ... Flange 3b ... Web 4 ... Main bar 5 ... Stirrup 6 ... Concrete 7 ... SRC construction 8 ... S construction 9 ... Stiffener 10 ... Nut 11 ... Horizontal rib

Claims (1)

(57) [Claims] 1. A stiffener for vertically partitioning a portion surrounded by a flange and a web at a boundary between both ends and a central portion of the H-shaped steel beam and other portions, and a shaft member of the H-shaped steel beam. Main bars and stirrups are arranged in the direction surrounded by flanges and webs only at both ends and the center of the beam as parts where bending stress is large for long-term load and short-term load in the direction, and concrete is cast. A composite beam characterized by incorporating a RC structure.