JPH08135013A - Beam made of reinforced concrete at the ends and steel skeleton at the middle - Google Patents

Abstract

PURPOSE: To eliminate concentration of bending stresses of a joint part, by widening the flange axes at the ends of a steel skeleton beam and providing bearing plates, joining grooves, etc., and binding the ends of main reinforcements of the concrete column side joined with the beam, with band plates. CONSTITUTION: The end of the flange 4 of a beam 3 made of I-shaped steel is formed slant and wide and the ends of web 8 are cut to form joining grooves 9. This beam 3 is welded with the main reinforcements 5 extended from a reinforced concrete column, at the external sides of the upper and lower flanges and the ends of main reinforcements are bound by band plates 7. A bearing plate 10 and auxiliary plates 11 are protruded at the boundary of the concrete part, in the beam 3 and also stirrups are arranged on the main reinforcements 5 and then concrete is placed to unify them. The structure is designed so that the bending stresses and shearing stresses are transferred smoothly from the beam 3 to the concrete part 2, at the front end of the beam 3 and the front end of the concrete part 2, where stresses are concentrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam having a reinforced concrete end and a steel frame center.

[0002]

2. Description of the Related Art In a building made of reinforced concrete having a large span, a beam 20 having a reinforced concrete structure at its end and a steel frame structure at its center is used as shown in FIG. It was thought that this beam 20 is configured by embedding an end portion of a steel frame 40 in a reinforced concrete portion 30 and transmits stress by a bearing mechanism as shown in the figure.

[0003]

However, in the beam having such a structure, the end of the steel frame is embedded in the reinforced concrete portion to increase the strength, but stress concentrates on the portions a and b in FIG. Therefore, there is a problem that stress is not smoothly transmitted from the steel frame to the reinforced concrete portion. Therefore, conventionally, there has been a problem that the cost is increased because the portion where the stress is concentrated is shear-reinforced.

The present invention has been made in view of the above problems, and an object thereof is to smoothly transmit stress from a steel frame to a reinforced concrete part in a beam having a reinforced concrete structure at the ends and a steel structure at the center. It is to be done.

[0005]

[Means for Solving the Problems] The means for solving the above problems is the invention of claim 1 in which both ends of a steel frame are embedded in a reinforced concrete part and the end part is reinforced concrete and the center part is In a steel-framed beam, flanges at both ends of the steel frame are formed wider than the reinforcing bar width of the main bar of the reinforced concrete part, and ends of the main bar of the reinforced concrete part attached to the flange are constrained by band plates, and the flange is formed. A joining groove in which the web is cut out is formed in between, and the bearing plate is projected at the boundary with the reinforced concrete portion of the steel frame.
The invention of claim 2 is a beam in which both ends of a steel frame are embedded in a reinforced concrete part and the ends are reinforced concrete structures and the central part is a steel frame structure, and both ends of the steel frame are near the rear end part of the reinforced concrete part. Rib plates are provided in the joint groove formed between the flanges, and the main bars of the reinforced concrete part are reinforced at both ends and the ends are restrained by band plates, and some of these main bars are While being welded to the flange of the steel frame, the main bars on both sides that are not welded to the flange are vertically connected to each other to form a U-shape, and a bearing plate is projected at the boundary between the steel frame and the reinforced concrete part. The present invention is characterized in that a reinforcing plate is attached to the pressure bearing plate.

[0006]

[Operation] The main bar of the reinforced concrete part is attached to the flange that is formed wider than the bar width of the main bar of the reinforced concrete part, so that the bending moment acting on the steel frame end is smoothly transmitted to the reinforced concrete part on the tensile side. To be done. Further, since the pressure bearing plate is provided at the boundary between the steel frame and the reinforced concrete portion, the bending moment is smoothly transmitted to the reinforced concrete portion on the compression side. Further, this transmission is further effectively performed because the end portion of the main bar is restrained by the steel frame by the band plate.

Further, since the joint groove is formed between the flanges, the smooth transmission of the bending moment to the steel-framed concrete becomes clear, and the surroundings of the poured concrete, that is, the filling property is improved.

Main bars of the reinforced concrete part are arranged in the steel frame deeply embedded in the reinforced concrete part, and some of these main bars are welded to the flange, and the main bars on both sides not welded to the flange are connected vertically. The bending moment acting on the end portion of the steel frame is smoothly transmitted to the reinforced concrete portion on the tension side due to the U-shaped configuration. Further, since the bearing plate is provided so as to project at the boundary between the steel frame and the reinforced concrete portion, the bending moment is smoothly transmitted to the reinforced concrete portion on the compression side. Further, this transmission is further effectively performed because the end portion of the main bar is restrained by the steel frame by the band plate.

Further, since the joint groove formed between the flanges is provided with the rib plate, the adhesive force between the reinforced concrete portion and the steel frame can be increased.

Further, the shearing force acting on the end of the steel frame is transmitted through a webbed flange embedded in the reinforced concrete portion.

Further, since the reinforcing plate is attached to the pressure bearing plate, the proof stress of the pressure bearing plate can be further increased.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A beam having a reinforced concrete structure at the end and a steel frame structure at the center according to the present invention will be described below in detail with reference to the drawings.

1 to 4 show an embodiment of the invention of claim 1, FIG. 1 is a vertical sectional side view of a beam having a reinforced concrete structure at an end and a steel frame at a central part, and FIG. 3 is a cross-sectional plan view of the same, and FIG. 4 is a sectional view taken along line AA of FIG.

As shown in FIG. 1, a beam 1 having a reinforced concrete structure at its ends and a steel structure at its central part is formed with reinforced concrete parts 2 at both ends and with a steel frame 3 at its central part. Both end portions of are embedded in the reinforced concrete portion 2 and configured.

At both ends of the steel frame 3, flanges 4 are formed wider than the reinforcing bar width of the main bars 5 of the reinforced concrete section 2, and all the main bars 5 of the reinforced concrete section 2 are welded to the flanges 4.

The welded main bar 5 is constrained by a stirrup 6 wound around it, and the tip of the main bar 5 is constrained to the steel frame 3 by a band plate 7.

A joining groove 9 formed by cutting out the web 8 is provided at the tip of the steel frame 5. Therefore, the steel frame 3 with the web 8 is
It is in a state of being embedded only in the tip end portion of the band plate 7, and the band plate 7 is wound around this portion.

A bearing plate 10 is welded to a boundary portion between the steel frame and the reinforced concrete portion 2. This bearing plate 10
Are welded between the upper and lower flanges 4 on both sides of the web 8 and project from the upper flange 4 and the lower flange 4 respectively. And this bearing plate 1
A reinforcing plate 11 is provided at 0 to further enhance the proof strength.

Next, the transmission of stress from the steel frame 3 to the reinforced concrete portion 2 will be described with reference to FIG. The tensile side of the bending moment is smoothly transmitted through the main bar 5 of the reinforced concrete portion 2 welded to the flange 4, as shown in (1) of the same figure. Also, this flange 4 is a web 8
Since the notch is notched, smooth transmission of stress becomes clear.

The compression side of the bending moment is smoothly transmitted to the reinforced concrete portion 2 via the bearing plate 10 provided at the boundary with the reinforced concrete portion 2 as shown in (1) of the figure.

Further, in this portion, the band plate 7 is wound to strengthen the restraining force of the reinforced concrete portion 2 and increase the bearing capacity thereof, so that the stress is effectively transmitted.

The shearing force is transmitted to the reinforced concrete portion 2 by the bearing capacity of the flange 4 having the web 8 as shown in (2) of the figure. Similar to the above, this is because the band plate 7 wound around this portion strengthens the restraining force of the reinforced concrete portion 2 and increases the bearing capacity thereof, so that the stress is effectively transmitted.

Further, FIG. 6 shows that all of the main bars 5 of the reinforced concrete section 2 are screw bars and the ends thereof are attached to the bearing plate 10 by nuts 12. With such a configuration, similarly to the above, the tensile stress of the bending moment can be smoothly transmitted to the reinforced concrete portion 2.

7 to 9 show the invention of claim 2, FIG. 7 is a vertical sectional side view of an end portion of a beam, FIG. 8 is a transverse plan view of the same, and FIG. 9 is C of FIG. It is a -C line sectional view.

As shown in FIG. 7, the end of the steel frame 3 is buried up to the deep position of the reinforced concrete portion 2, and the rib plates 13 are provided above and below the joining groove 9 at this end at appropriate intervals. There is.

The rib plate 13 is for strengthening the adhesion between the steel frame 3 and the reinforced concrete portion 2, and an L-shaped angle is welded to the upper flange 4 and the lower flange 4.

As for the main bar 5 of the reinforced concrete portion 2 arranged at the end of the steel frame 3, the central bar 5 is welded to the flange 4, but the main bars 5 on both sides which are not welded to the flange 4 are The upper and lower parts are connected to each other to form a U-shape.

The ends of the main bars 5 and the U-shaped main bars 5 welded to these flanges 4 are bound to the steel frame 3 by a band plate 7. The rest of the configuration is the same as the invention of claim 1.

[0029]

[Effects of the Invention] Since the main bar of the reinforced concrete part is attached to the flange formed wider than the reinforcing bar width of the main bar of the reinforced concrete part, the bending moment acting on the steel frame end is smoothed to the reinforced concrete part on the tensile side. Be transmitted to. Further, since the bearing plate is provided at the boundary between the steel frame and the reinforced concrete portion, the bending moment is smoothly transmitted to the reinforced concrete portion on the compression side. Further, this transmission is further effectively performed because the end portion of the main bar is restrained by the steel frame by the band plate. Further, the shearing force acting on the end portion of the steel frame is transmitted through a webbed flange embedded in the reinforced concrete portion. Therefore, the stress can be smoothly transmitted from the steel frame to the reinforced concrete portion.

Since the joint groove is formed between the flanges, smooth transmission of the bending moment to the steel-framed concrete portion becomes clear, and at the same time around the cast concrete,
That is, the filling property is improved.

Main bars of the reinforced concrete part are laid in a steel frame deeply embedded in the reinforced concrete part, and some of these main bars are welded to the flange, and main bars on both sides not welded to the flange are connected vertically. The bending moment acting on the end portion of the steel frame is smoothly transmitted to the reinforced concrete portion on the tension side due to the U-shaped configuration. Further, since the bearing plate is provided at the boundary between the steel frame and the reinforced concrete portion, the bending moment is smoothly transmitted to the reinforced concrete portion on the compression side. Further, this transmission is further effectively performed because the end portion of the main bar is restrained by the steel frame by the band plate. Furthermore, the shearing force acting on the end of the steel frame is
It is transmitted via a webbed flange embedded in the reinforced concrete section. Therefore, the stress can be smoothly transmitted from the steel frame to the reinforced concrete portion.

Further, by providing the rib plate in the joint groove between the flanges, the adhesive force between the reinforced concrete portion and the steel frame can be increased.

Since the reinforcing plate is attached to the pressure bearing plate, the proof stress of the pressure bearing plate can be further increased.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of a beam having a reinforced concrete structure at its ends and a steel frame structure at its center.

FIG. 2 is a vertical sectional side view of an end portion of a beam.

FIG. 3 is a cross-sectional plan view of the end of the beam.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a conceptual diagram showing stress transmission.

FIG. 6 (1) is a vertical sectional side view in which a main bar is screwed to a bearing plate,
(2) is a BB line sectional view of (1).

FIG. 7 is a vertical sectional side view of an end portion of a beam.

FIG. 8 is a cross-sectional plan view of the end of the beam.

FIG. 9 is a sectional view taken along the line CC of FIG. 8;

FIG. 10 is a vertical cross-sectional side view of a beam having a conventional reinforced concrete structure at the end and a steel frame structure at the center.

[Explanation of symbols]

 1 Beam with reinforced concrete structure at the end and steel frame at the center 2 Reinforced concrete part 3 Steel frame 4 Flange 5 Main bar 6 Starlap 7 Band plate 8 Web 9 Joining groove 10 Bearing plate 11 Reinforcement plate 12 Nut 13 Rib plate

Front page continuation (72) Inventor Takayuki Oi 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Toshio Toriya 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd.

Claims (3)

[Claims] 1. A beam having both ends of a steel frame embedded in a reinforced concrete part, the ends being a reinforced concrete structure and the central part being a steel frame structure, and the flanges at the both ends of the steel frame are flanged bar reinforcement widths of the reinforced concrete part. Wider than that, the end of the main bar of the reinforced concrete part attached to the flange is constrained by a band plate, a joint groove in which a web is cut is formed between the flanges, and the boundary part with the reinforced concrete part of the steel frame is formed. A beam with a reinforced concrete structure at the end and a steel frame structure at the center, which is characterized by a pressure bearing plate protruding. 2. A beam having both ends of a steel frame embedded in a reinforced concrete part, the ends being a reinforced concrete structure and the central part being a steel frame structure, the both ends of the steel frame being buried up to near the rear end part of the reinforced concrete part. Rib plates are provided in the joint grooves formed between the flanges, and the main bars of the reinforced concrete part are arranged at both ends and the ends are restrained by band plates, and some of these main bars are made of steel. While being welded to the flange, the main bars on both sides which are not welded to the flange are vertically connected to each other to form a U-shape, and a bearing plate is projected at the boundary with the reinforced concrete part of the steel frame. A beam made of reinforced concrete at the end and a steel frame at the center. 3. A beam having a reinforced concrete end and a steel frame center as claimed in claim 1 or 2, wherein a reinforcing plate is attached to the bearing plate.