JP2003056119A - Bond splitting preventing reinforcement and concrete member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bond splitting preventing reinforcement and a concrete member with inexpensive reinforcement arrangement and high fracture strength. SOLUTION: A plurality of U-shaped or crank shaped bond splitting preventing reinforcements 4 and 5 are arranged along main reinforcements 2 so as to embrace the main reinforcements 2 by curved parts of U-shapes or leg parts of crank shapes. A ladder shaped material with the plurality of bond splitting preventing reinforcements 4 and 5 coupled by a coupling member extended in an axial direction of the main reinforcements is arranged along the main reinforcements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive split preventing bar for effectively and efficiently improving the strength of a reinforced concrete member such as a concrete column or a beam, and a concrete member using the bar.

[0002]

2. Description of the Related Art For concrete columns and beams, cage-shaped reinforcing bars are generally used which are arranged by winding shear reinforcing bars in a hoop shape around the outer circumference of main reinforcing bars arranged in the axial direction. A high-strength steel material is used for the shear reinforcing bar in order to increase the shear strength of the member.

When the strength of such a reinforced concrete structure is calculated, the shear strength formula (Qsu) and the bond strength formula (Qbu) are used, and the smaller one is adopted.

The strength of concrete and shear reinforcing bars used for concrete columns or beams in recent high-rise buildings has been increased. For this reason, the strength of the member tends to be determined not by the shear strength formula (Qsu) but by the adhesion strength formula (Qbu). In this way, the strength of the member is determined by the bond splitting fracture around the main bar, and even if the shear reinforcing bar has a high strength, its superiority is halved. Therefore, even if the strength of the shear reinforcing bar is increased or the reinforcing amount is increased, the strength of the member is not improved due to the split fracture. In addition, the cost is high because unnecessary high-strength shear reinforcing bars are used.

[0005]

DISCLOSURE OF THE INVENTION The present invention uses a low-priced steel material on the general market as a bond splitting prevention bar, and increases the bond strength by a simple construction, so that the effect of a high-strength shear reinforcing bar is sufficiently obtained. It is an object of the present invention to provide an adhesion splitting preventing bar and a concrete member using the same, which can be drawn out to improve the performance of the concrete member and effectively and economically exhibit the strength and cost of the concrete member.

[0006]

In order to achieve the above object, the U-shaped attachment split preventing bar of the concrete member of the present invention is a U-shaped reinforcing bar surrounding the main bar at the U-shaped curved portion, and its foot portion. Are arranged along the main bar so as to face the inside of the concrete member at right angles to the axial direction of the main bar.

Alternatively, the U-shaped attachment splitting preventive bar of the concrete member of the present invention is a U-shaped reinforcing bar, both legs of the C-shaped hug each have a different main bar, and the U-shaped foot and the back are the axes of the main bar. It is characterized in that it is arranged along the main bar so that the legs are orthogonal to the direction and face the inside of the concrete member.

Further, the concrete member of the present invention is characterized in that a plurality of the U-shaped attachment / split prevention bar or the U-shaped attachment / split prevention bar are arranged along the main bar.

That is, according to the present invention, in order to prevent the action of splitting the concrete along the main bar when an external force is applied to the concrete member, a U-shaped or U-shaped adhesive splitting prevention bar surrounding the main bar is provided. Is provided to restrain the adhesion of concrete to suppress the splitting fracture and improve the strength of the concrete member. Thereby, since the high-strength shear reinforcing bar can be effectively used, the wire diameter of the shear reinforcing bar can be reduced or the number thereof can be reduced, and the cost of the reinforcing bar can be reduced.

Incidentally, the U-shape of the adhesive splitting preventing muscle referred to here includes not only the shape in which the curved portion is circular, but also the shape in which the bent portion is convex like V-shaped. Further, the U-shape and the U-shape of the attachment splitting preventing muscle also include a shape in which the tips of the legs are bent as shown in FIGS. 2 (b) and 3 (b).

In addition, the U-shaped attachment splitting prevention bar or the U-shaped attachment splitting prevention main bar of the concrete member is provided with a plurality of the U-shaped attachment splitting prevention bar or U-shaped attachment splitting bar by the connecting member extended in the axial direction. It can be easily constructed by connecting the prevention bars in a ladder shape and disposing the connected ladder members along the main bars.

Further, the concrete member of the present invention is preferably provided with a high-strength shear reinforcing bar and the adhesion split preventing bar made of a low-strength steel material. Thereby, the performance of the member can be effectively and economically improved.

That is, if the adhesive split preventing bar of the present invention is used, the high strength of the shear reinforcing bar is effectively utilized. Therefore, the adhesive split preventing bar may be a low-strength steel material, which reduces the cost of the reinforcing bar and increases the cost. A strong concrete member is obtained.
Deformed or round steel is used for the low-strength steel.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be specifically described below. FIG. 1 is a cross-sectional view of a reinforced concrete member to which an adhesive split preventing bar according to an embodiment of the present invention is applied. The upper half of the figure is in a state where a U-shaped adhesive split preventing bar is used, and the lower half is a U-shaped adhesive crack preventing The state when a muscle is used is shown. 2A and 2B are external views of the U-shaped attachment / split preventing muscle, wherein FIG. 2A shows a leg having a straight line and FIG. 2B shows a leg having a bent tip. 3A and 3B are external views of the U-shaped attachment splitting preventing muscle, wherein FIG. 3A shows a leg having a straight line, and FIG. 3B shows a leg having a bent tip. FIG. 4 is a construction drawing of a U-shaped attachment splitting prevention bar assembled in a ladder shape, and FIG. 5 is a construction drawing of a U-shaped attachment splitting prevention bar assembled in a ladder shape.

As shown in the sectional view of FIG. 1, in the concrete member 1, shear reinforcing bars 3 are arranged around a plurality of main bars 2 arranged in the axial direction. In the case of the U-shaped attachment split preventing muscle 4 of the present invention, it is arranged as shown in the upper half of FIG. 1, and in the case of the U-shaped attachment split preventing muscle 5, it is arranged as shown in the lower half of FIG. Be streaked.

First, the U-shaped attachment split preventing muscle 4 will be described. As shown in FIG. 2, the U-shaped attachment split preventing muscle 4 is
It is formed into a U-shape having a bent portion 4a having a shape in which a round or deformed rebar is bent to surround the main bar 2 and foot portions 4b are provided at both ends. The U-shaped attachment splitting preventing muscle has a straight leg portion 4b as shown in FIG. 2 (a) and a leg portion 4b as shown in FIG. 2 (b).
Any of those having a bend 4c at the tip thereof is used, but the method of use is the same. As shown in the upper half of FIG. 1, the curved portion 4a surrounds the main bar 2, the leg 4b is orthogonal to the main bar 2, and the distal ends of the legs are arranged so as to face the inside of the structure 1. At the corners of the concrete member, as shown in the drawing, the feet are arranged toward the center of the concrete member.

When arranging a plurality of U's, as shown in FIG.
If the outside of the curved portion 4a of the character-shaped attachment splitting preventing bar 4 is connected to the connecting member 6 by welding or the like to form a ladder shape, and this ladder shape member is arranged around the main bar 2 as shown in FIG. A plurality of U-shaped attachment split preventing muscles 4 can be arranged in the.

As a result, the concrete around the main reinforcing bar 2 is restrained by the U-shaped adherent split preventing bar 4, the splitting fracture of the concrete is prevented, and the concrete strength is improved.

Next, the U-shaped attachment splitting preventing muscle 5 will be described. As shown in FIG. 3, the U-shaped attachment splitting preventing muscle 5 is
A round or deformed reinforcing bar is bent to have a U-shape having a back portion 5a and a foot portion 5b. Then, as shown in the lower half of FIG. 1, the two main muscles 2 and 2 are held by the foot portions 5b on both sides, and the back portion 5a is arranged orthogonal to the axis of the main muscle 2. As for the U-shaped attachment splitting prevention muscle, both the leg portion 5b having a straight line as shown in FIG. 3 (a) and the leg portion 5b provided with a bend 5c as shown in FIG. 3 (b) are used. However, the method of use is the same.

Also in the case of the U-shaped attachment / split prevention bar 5, when arranging, as shown in FIG. 5, the outsides of the back portions 5a of the plurality of U-shaped attachment / split prevention bars 5 are connected by a connecting member 7 by welding or the like. By forming a ladder shape and disposing this ladder shape member around the two main bars 2 and 2 as shown in FIG. 5, a plurality of U-shaped attachment split preventing bars 5 can be easily arranged.

As a result, the concrete around the main bar 2 is restrained by the U-shaped adhesive split preventing bar 5, and like the U-shaped adhesive split preventing bar 4, the fracture of concrete is prevented and the concrete strength is improved.

[0022]

As described above, the U-shaped adhesive splitting prevention bar of the present invention and the concrete member using the same are U-shaped.
Since the U-shaped or U-shaped adhesive splitting prevention muscle is arranged along the main bar, the action of attempting to split the concrete along the main bar when external force acts on the concrete member is suppressed by the adhesive splitting prevention bar, Improve the strength of concrete members.

That is, since the high strength of the main reinforcing bar and the shear reinforcing bar is effectively utilized when the adhesive split preventing bar of the present invention is used, when the member strength is calculated, the high strength shear reinforcing bar is used in the shear strength formula. By using reinforcing bars, and by additionally using inexpensive adhesive split preventing bars in the bond strength formula, it is possible to further reduce the cost of the reinforcing bar and to obtain a highly reliable concrete member at low cost with high reliability.

Further, a plurality of U-shaped attachment splitting preventing bars or U-shaped attachment splitting preventing bars are connected in a ladder shape by a connecting member extending in the axial direction, and the ladder-shaped members are arranged along the main bars. If this is done, construction of the bar arrangement becomes easier, and construction costs can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a reinforced concrete member provided with an adhesion split preventing bar of an embodiment of the present invention.

FIG. 2 is an external view of a U-shaped attachment split preventing muscle according to the embodiment of the present invention.

FIG. 3 is an external view of a U-shaped attachment splitting preventing muscle according to the embodiment of the present invention.

[Fig. 4] Fig. 4 is a construction drawing of a U-shaped attachment splitting prevention bar assembled in a ladder shape according to the embodiment of the present invention.

FIG. 5 is a construction diagram of a U-shaped attachment splitting prevention bar assembled in a ladder shape according to the embodiment of the present invention.

[Explanation of symbols]

1 concrete members, 2 main bars, 3 shear reinforcement bars,
4, 4'U-shaped adhesive split preventing muscle 5, 5'U-shaped adhesive split preventing muscle, 6 connecting member, 7 connecting member

Claims (7)

[Claims] 1. A U-shaped reinforcing bar surrounds the main bar around the U-shaped bent portion, and its foot portion is disposed along the main bar so that the legs are orthogonal to the axial direction of the main bar and face the inner side of the concrete member. U-shaped attachment splitting prevention bar of a concrete member, characterized in that 2. A U-shaped reinforcing bar, wherein both legs of the U-shape hold separate main bars, the U-shaped foot and the back are orthogonal to the axial direction of the main bar, and the feet are on the inner side of the concrete member. A U-shaped attachment split preventing bar of a concrete member, which is arranged along the main bar so as to face to. 3. A U-shaped attachment splitting preventive bar in which a U-shaped curved portion surrounds the main bar is arranged on the main bar so that the U-shaped foot portion faces the inside of the concrete member at right angles to the axial direction of the main bar. A concrete member characterized in that a plurality of them are arranged along it. 4. A plurality of the U-shaped attachment-splitting prevention bars are connected in a ladder shape by a connecting member extending in the axial direction of the main bar, and the connected ladder-shaped members are arranged along the main bar. The concrete member according to claim 3, wherein 5. The U-shaped attachment splitting preventing muscle in which both U-shaped legs hold different main muscles, the U-shaped foot portion and the back portion are orthogonal to the axial direction of the main muscle, and the foot portions are inside the concrete member. A concrete member characterized in that a plurality of the members are arranged along the main bar so as to face the side. 6. A plurality of the U-shaped attachment / split preventing bars are connected in a ladder shape by a connecting member extending in the axial direction of the main bar, and the connected ladder members are arranged along the main bar. The concrete member according to claim 5, wherein 7. The concrete member according to claim 3, wherein a high-strength shear reinforcing bar and the adhesive split preventing bar made of a low-strength steel material are provided.