JPH04306346A - Reinforcing bar for reinforced concrete beam-column - Google Patents

Abstract

PURPOSE:To sufficiently exhibit the shear reinforcing effect and lateral restricting effect of high-strength shear reinforcing bars. CONSTITUTION:Both ends 12a of a circumferentially directed reinforcing bar 12 wound in a ring form around main reinforcements 11 are wound around angular main reinforcements 11 along the other side bodies 12b, and the ends 12a are connected with the bodies 12b by binders 13. Both ends 12a hooked at 135 deg. of the reinforcing bars 12 are connected by binders.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to shear reinforcing bars buried in the circumferential direction inside reinforced concrete beams and columns,
Concerning the structure of reinforcing bars such as lateral restraint bars.

0002

[Background Art] In recent years, as structures have become taller and larger, it has become necessary to further enhance the shear reinforcement effect and lateral restraint effect, and high-strength shear reinforcement or lateral restraint reinforcement with a yield point of 600 to 1,300 MPa is used. A technology has been developed to do so. By using such high-strength reinforcement, bending failure occurs first in reinforced concrete members, making it possible to completely prevent shear failure, and the lateral restraint effect of concrete allows for a significant increase in compressive failure strain. As a result, it is now possible to freely improve the bending toughness required by the component. In any case, the basic condition for achieving 100% of the reinforcing effect is not to allow the shear reinforcing bars or lateral restraining bars to yield before the member is destroyed.

In order to obtain such shear reinforcing effects and lateral restraining effects, conventionally parallel main reinforcements 1, 1, . . . as shown in FIG.
Wrap the shear reinforcing bar 2 around the outside of..., and wrap the shear reinforcement 2 around the outside of the
1b is wrapped around the same corner main reinforcement 1 and curved at about 135 degrees to form a hook shape to prevent it from coming off.
So-called hook anchoring, a single shear reinforcing bar 3 spirally wound around the outer circumference of the main bars 1, 1, etc. as shown in Fig. 7, and furthermore, as shown in Fig. 8, the main bars 1, 1... Generally, both ends of each shear reinforcing bar 4 wound around... were butted against each other to form a continuous ring shape with a welded part 5 interposed therebetween.

0004

[Problem to be solved by the invention] However, the conventional 135
When using high-strength shear reinforcing bars as described above, when a reinforced concrete member is loaded and the reinforcing bars are pulled, and the tensile force exceeds a certain level, the tensile strength of the reinforcing bars increases. There was a problem in that the reinforcing bars slipped out of the anchoring part of the 135 degree hook anchoring before reaching the limit, and the reinforcing effect was lost without exerting high tensile stress.

[0005] Particularly, just before the reinforced concrete member reaches its final stage of failure (or after the maximum load is reached), the cover concrete outside the reinforcing bars peels off, and as a result, the anchoring force of the 135-degree hook portion is rapidly lost. According to research conducted by the present inventors, 135 degree hook anchoring is effective only when the tensile stress of the reinforcing bars is at most about 500 MPa. Therefore, when using high-strength reinforcing bars, there is a problem in that the effect of high strength cannot be fully demonstrated by hook fixing at 135 degrees.

On the other hand, shear reinforcing bars in a spiral shape or in a ring shape by welding maintain their reinforcing effect unless they are cut. However, there is a problem in that it cannot be used for anything other than factory-produced products. In addition, with ring-shaped shear reinforcement bars made by welding, there is a problem with the reliability of the welded part, and when the member is subjected to repeated action of large stress close to the fracture strength, such as during an earthquake, the reinforcing bar's low cycle There was a problem that tensile fatigue failure was a concern.

In view of these conventional problems, the present invention is capable of fully demonstrating the strength of high-strength reinforcing bars, is easy to process and assemble on-site, and is highly reliable. The purpose is to provide shear reinforcement for high reinforced concrete columns and beams.

[0008]

[Means for achieving the object] The features of the present invention for solving the conventional problems as described above and achieving the initial objectives are as follows:
First, in reinforcement bars for reinforced concrete column and beam materials, which are wrapped around multiple parallel main bars in a ring shape,
A reinforced concrete column and beam material, characterized in that both ends are wrapped around at least one corner main reinforcement, each of the ends is overlapped in parallel with the other side, and each overlapped part is tied with a binding material. Second, in reinforcing bars for reinforced concrete columns and beams, which are wrapped around multiple parallel main bars in a ring shape, both ends are wrapped around the same corner main bars, and both ends are wrapped around the same corner main bars. A reinforcing bar for reinforced concrete columns and beams is characterized in that the reinforcing bars are bent in parallel to each other and the parallel portions at both ends are bound with a binding material.

[0009] In addition to hard wire and steel bands, binding materials include hard wire and steel bands.
Use steel sleeves.

0010

[Operation] In the present invention, when a load is applied to the concrete column and beam material and tensile force is applied to the shear reinforcing bars, a force is applied to both ends of the reinforcing bars to open them in a direction away from the main reinforcing bars at each part. At this time, since both ends of the reinforcing bars are bound to the other side by a binding material, opening is prevented and the reinforcing bars can withstand tensile force up to the maximum tensile stress.

[0011]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention,
In the figure, 10 is a column or beam concrete, 11 is a main reinforcement, and 12 is a circumferential reinforcement such as a shear reinforcement or a lateral restraint reinforcement. This circumferential reinforcing bar 12 has both end parts 12a, 12a wrapped around a single common corner main bar 11a, and is bent along the other body part 12b, 12b, so that each end part 12a and the body part 12b are bent together. and are bound together with a binding material 13 made of wire.

FIG. 2 shows a second embodiment of the invention,
In this embodiment, both ends of the circumferential reinforcing bars 12 are overlapped between the two corner main bars 11a, 11b adjacent to each other, and the tips 12a, 12a are wrapped around each corner main bar 11a, 11b. Hang the body part 12c, 1 on the other side.
2c, and each end portion 12a and body portion 12c are bound together with a binding material 13 made of wire.

FIG. 3 shows a third embodiment of the present invention,
In this embodiment, both ends 12a of the circumferential reinforcing bar 12 are
, 12a is bent into a hook shape at 135 degrees to form one main corner reinforcement 1.
1a, the condition is the same as the conventional 135 degree hook fixing, and both ends 12a, 12a arranged parallel to each other are bound with a binding material 13 made of wire.

Although the binding wire conventionally used for assembling reinforcing bars is a dulled iron wire, it is preferable to use high-strength wire as the binding material in the above-described embodiment of the present invention.

In addition to wire, a metal sleeve 14 as shown in FIG. 4 may be used, or a binding fitting 15 made by cutting and crimping a strip as shown in FIG. 5 may be used.

[0017]

[Effects of the Invention] As described above, in the reinforcing bar for reinforced concrete column and beam materials of the present invention, both ends are wrapped around at least one longitudinal bar, and the tip end is tied to the other side. This prevents the tip from springing out in the direction in which it tries to extend when tensile force is applied, and the shear reinforcement effect and lateral restraint effect are not lost until the reinforcement is severed, and the welded part There is no need to worry about strength loss due to material deterioration or low-cycle tensile wave damage, which is the case with ring-shaped products, resulting in higher reliability, and additional benefits such as ease of processing and assembly on-site. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a first embodiment of the invention.

FIG. 2 is a sectional view of a second embodiment of the invention.

FIG. 3 is a sectional view of a third embodiment of the invention.

FIG. 4 is a perspective view of another example of the binding material used in the present invention.

FIG. 5 is a sectional view of still another example of the binding material used in the present invention.

FIG. 6 is a cross-sectional view of an example of the prior art.

FIG. 7 is a cross-sectional view of another example of the prior art.

FIG. 8 is a perspective view of still another example of the prior art.

[Explanation of symbols]

10　Column, beam concrete 11 Main reinforcement 11a, 11b Square main reinforcement 12 Circumferential reinforcing bars 12a Both ends 12b, 12c Trunk 13 Binding material 14 Metal sleeve 15 Binding fittings

Claims (4)

[Claims] [Claim 1] Reinforcing bars for reinforced concrete columns and beams that are wound around a plurality of parallel main reinforcements in a ring shape, with both ends wrapped around at least one main corner reinforcement, and the tip side A reinforcing bar for reinforced concrete columns and beams, characterized in that each side is overlapped parallel to the other side, and each overlapped part is tied with a binding material. [Claim 2] Reinforcing bars for reinforced concrete columns and beams that are wound around a plurality of parallel main reinforcements in a ring shape, with both ends wrapped around the same corner main reinforcement so that the ends are arranged parallel to each other. A reinforcing bar for a reinforced concrete column and beam material, characterized in that the reinforcing bar is bent and the parallel parts at both ends are tied with a binding material. [Claim 3] Claim 1, wherein wire is used as the binding material.
Or the reinforcing bars for reinforced concrete column and beam materials described in 2. 4. The reinforcing bar for reinforced concrete column and beam materials according to claim 1 or 2, wherein a steel sleeve is used as the binding material.