JP4474669B2 - Unit rebar connection method - Google Patents

Description

  The present invention relates to a lattice unit reinforcing bar embedded in concrete to reinforce a concrete product such as a concrete foundation or a concrete wall of a building or civil engineering. Specifically, the reinforcing bar constituting the unit reinforcing bar is vertically and horizontally arranged. It is related with the method of connecting easily to.

  Conventionally, when constructing a reinforced concrete structure, the bar arrangement work that arranges the reinforcing bars vertically and horizontally at predetermined intervals has been carried out manually by craftsmen. Unit rebars are formed by bundling the intersections of the rebars and horizontal bars with a bundling wire made of mild steel wire or by welding.

  Reinforcing bars used for unit reinforcing bars are standardized with hooked reinforcing bars whose ends are bent at a predetermined angle. For example, 90 degree hooks with the ends of the reinforcing bars bent at right angles, 135 degrees and 180 degrees There are bent 135-degree hooks, 180-degree hooks, etc., but these hooks are only used for making a frame with reinforcing bars arranged in the crossing direction. Wire and welding are used.

In addition, as a reinforced concrete (RC) foundation for low-rise industrialized houses (prefabricated houses) and conventional wooden houses, it is common to use a unit rebar assembled in advance at the factory stage. This unit rebar is placed in a basic module preset in the target prefabricated house, and then a formwork is installed around the placed unit rebar, and concrete is placed in this formwork to build an RC foundation. To do.
As a known technique of unit rebar, there are, for example, Japanese Patent Laid-Open No. 11-36589 (Patent Document 1) and Japanese Patent Laid-Open No. 06-57874 (Patent Document 2), and the vertical bar and the horizontal bar are connected by binding or welding. Has been.

JP 11-36589 A (first page) Japanese Patent Laid-Open No. 06-57874 (first page)

  In the unit reinforcing bars disclosed in Patent Documents 1 and 2, there are many connecting portions between the vertical bars and the horizontal bars, and a great amount of time and labor are required for the frame and the connecting work. Further, in the connection by welding, since the reinforcing bar as the base material is melted, there are problems such as loss of cross-sectional area, difficulty in thermal management, and reduction in structural strength of the reinforcing bar. In particular, in the case of unit reinforcing bars, if welding heat is applied to the main bars on both sides held by the shear reinforcing bars, the strength of the main bars may be reduced and the material may be changed.

  The present invention has been made against the background of such a situation, and the object of the present invention is to reduce the number of binding wires and welding points as much as possible when connecting the reinforcing bars in a lattice shape to produce unit reinforcing bars. An object of the present invention is to provide a method for connecting unit reinforcing bars, which can improve productivity and workability, and can prevent problems such as a decrease in strength and a material change due to welding heat as much as possible.

In order to solve the above problems, the present invention relates to a unit rebar connecting method in which reinforcing bars are combined in a lattice shape and embedded in a concrete product, and among the reinforcing bars constituting the lattice shape, one end of the reinforcing bar is unidirectional. the part near by bending, with winding the bend in the other direction of the reinforcement, further superposing the one direction of the end tip side remaining straight portion of the reinforcing bars are overlapped with the unidirectional reinforcement portion the closed loop is formed between the curved portion and the straight portion Nde small narrowing down the curved portion so as to intersect with a, the curved by preventing spring back by the frictional force of the overlapping portions The portion is tightened so as to hold the reinforcing bar in the other direction without loosening and connects the reinforcing bar in the other direction and the reinforcing bar in the one direction.
According to the present invention, in the method for connecting unit reinforcing bars according to claim 1, the bending angle of the closing ring is 225 degrees.
More preferably, the tip end side of the unidirectional reinforcing bar protrudes from the unidirectional reinforcing bar to the side opposite to the curved portion.

The unit reinforcing bar of the present invention is one of reinforcing bars that are assembled in a lattice pattern at a reinforcing bar manufacturing process site, for example, the vicinity of one end of a horizontal bar is bent, and this curved part is wound around the other vertical bar, and further, The bending portion is narrowed down while bending the end tip side back in the direction of the transverse muscle, and the leading edge side of the end portion is overlapped with the transverse muscle so that the bending portion tightens the longitudinal muscle and connects the longitudinal muscle and the longitudinal muscle. To do.
Further, at the other end portion of the horizontal bar, both the vertical and horizontal bars are connected in the same manner as the one end side.

  A bending machine is used for bending in the vicinity of the end of the reinforcing bar, and the bending portion formed on one end side or the other end side of the horizontal bar is wound so as to be in close contact with the vertical bar without a gap. An appropriate bending back angle of the reinforcing bar is around 225 degrees.

  Generally, bending the end of a reinforcing bar and simply wrapping the curved part around the reinforcing bar arranged in the crossing direction generates a so-called springback in which a force in the return direction opposite to bending acts on the bending part. As a result, the curved portion expands to a large diameter, and the winding force on the reinforcing bars in the crossing direction is weakened.

  In addition, the bending back of one end of one reinforcing bar in the present invention is overlapped with the one reinforcing bar, but the bending return position of one reinforcing bar is not overlapped with the one end reinforcing end. If it stops in front, the bending part will not be narrowed down, leaving a gap between the bending part and the other reinforcing bar, and the other reinforcing bar cannot be connected without loosening.

On the other hand, in the present invention, since the tip end side of one reinforcing bar is bent back to the reinforcing bar and overlapped, the spring back hardly occurs.
The front end side of the end portion of the reinforcing bar protrudes from the reinforcing bar to the side opposite to the curved portion, so that the spring back is less likely to occur.

  Moreover, when combining the reinforcing bar of another direction with the intermediate part of the reinforcing bar of one direction, the crossing part of these reinforcing bars is connected by a binding wire or welding. Therefore, in the present invention, in the intermediate part of the unidirectional reinforcing bar, the reinforcing bars in the other direction may be connected together with the binding wire and the welding, but at both ends of the unidirectional reinforcing bar, the bending part is bent and processed in the other direction. Since it is the structure connected with a reinforcing bar, the number of places connected by binding wires and welding is reduced compared to the conventional one.

  Furthermore, since the rebar of the present invention does not matter in shape or material, it may be a round rebar with a circular cross section, a deformed rebar with a rib on the outer peripheral surface, or other shapes, and a high-strength rebar or ultra-high-strength rebar is also used. be able to.

According to the unit reinforcing bar of the present invention, the reinforcing bar in the other direction can be connected by a simple operation of simply bending the vicinity of the end of the reinforcing bar in one direction, so that the working time can be reduced and the labor can be reduced. Productivity can be improved. In addition, since the number of connected portions by binding wires and welding is reduced as compared with the conventional one, workability is improved and the reinforcing bars are not damaged, so that a reduction in connection strength can be prevented as much as possible. In particular, since the present invention can be applied to the main reinforcing bars located on both sides of the unit reinforcing bars, the main reinforcing bars can be maintained in their original strength and material without being welded to the main reinforcing bars.
Furthermore, since the entire unit rebar can be assembled at the manufacturing process site, the production process time of the concrete product at the transport destination can be shortened.

Hereinafter, embodiments of a unit reinforcing bar according to the present invention will be described with reference to the drawings.
In the figure, FIG. 1 is an enlarged view of a main part showing a connection state of reinforcing bars used for unit reinforcing bars, FIG. 2 is an explanatory view showing a connecting procedure of reinforcing bars similarly used for unit reinforcing bars, and FIG. FIG.

In the connection shown in FIGS. 2A and 2B, ribs with different diameters are used for the horizontal bars 1 serving as shear reinforcement bars and the vertical bars 2 serving as the main bars.
First, in FIG. 2A, vertical bars 2 and 2 are arranged in the crossing direction in the vicinity of the left and right ends of the horizontal bar 1 having a required length, and the vicinity of the end of the horizontal bar 1 is vertically used by using a folding machine (not shown). It is bent around the muscle 2 and the bending portion 1 a is wound around the outer peripheral surface of each longitudinal muscle 2.

  Next, the bending portion 1a is narrowed down while bending the linear portion 1b (the end tip side of the reinforcing bar in one direction of the present invention) left on the end side of the end of the horizontal bar 1 in the direction of the horizontal bar 1, and further. As shown in FIG. 2B, the linear portion 1b is superimposed on the horizontal stripe 1 so that the curved portion 1a and the linear portion 1b constitute a closed ring 3.

  As shown in detail in FIG. 1, since the linear portion 1 b of the closing ring 3 is overlapped with the horizontal stripe 1, the curved portion 1 a is narrowed down to tighten the vertical stripe 2 without any gaps. The vertical bars 2 and 2 are connected to both ends without looseness. The bending angle of the closed ring 3 is approximately 225 degrees.

Further, when the linear portion 1b and the horizontal stripe 1 are overlapped, a frictional force is generated between them, so that the springback of the closing ring 3 is well prevented and the curved portion 1a does not loosen the vertical stripes 2 and 2. Hold. In addition, in the present embodiment, the use of different diameter reinforcing bars for the horizontal bars 1 allows the outer peripheral surfaces and ribs of the deformed bars to be hooked with each other. , 2 are held more firmly.
In the left and right vertical bars 2 and 2, a plurality of horizontal bars 1 are connected at a predetermined pitch in this way to form a lattice shape, and unit reinforcing bars of a required size are formed.

In the application example shown in FIG. 3, a plurality of transverse muscles 1 and longitudinal muscles 2 constituting the same are used as those which are longer than those shown in FIGS. It is a relatively large unit reinforcing bar 5 to which three vertical bars 4 are added.
A plurality of transverse bars 1 (shear reinforcement bars) and longitudinal bars 2 and 2 (main bars) on both left and right sides are connected to the longitudinal bars 2 by a closed ring 3 in which the ends of the transverse bars 1 are bent back in the same manner as in FIGS. The other means is used, and the other crossing points of the transverse muscle 1 and the longitudinal muscle 4 (abdominal muscle) are bound using a binding wire 6 made of a mild steel wire rod.
Note that spot welding may be used in place of the binding wire 6.

  In this application example, the connection using the closed ring 3 at the end of the transverse bar 1 and the connection using the binding wire 6 at the intermediate crossing portion are combined, but as compared with the conventional connection using only the binding wire 6. Since the number of binding locations is reduced, the working time can be shortened and the productivity can be improved. In particular, since the connecting method of the present invention is applied to the vertical bars 2 and 2 positioned as the main bars on both sides, no welding heat is applied to the vertical bars 2 and 2, and the original strength and material performance as the main bars are improved. Can be maintained.

It is a principal part enlarged view which shows the connection state of the reinforcing bar used for the unit reinforcing bar which shows one Example of this invention. It is explanatory drawing which shows the connection procedure of the reinforcing bar used for the unit reinforcing bar which shows one Example of this invention. It is a general view of a unit rebar showing an application example of the present invention.

Explanation of symbols

1 ... Transverse (shear reinforcement)
DESCRIPTION OF SYMBOLS 1a ... Curved part 1b ... Linear part (The edge part front end side of one reinforcing bar of this invention)
2 ... Longitudinal (main)
3 ... Closure ring formed by the curved part 1a and the linear part 1b 4 ... Longitudinal muscle (abdominal muscle)
5 ... Unit reinforcement 6 ... Bundling wire

Claims (2)

In the connecting method of unit rebars embedded in concrete products by combining rebars in a lattice shape,
Among the reinforcing bars constituting the lattice shape, the vicinity of the end of the reinforcing bar in one direction is curved, and the curved part is wound around the reinforcing bar in the other direction,
Further, the straight line Nde small narrowing down the curved portion so as to cross the end tip side straight portion left in the direction of the reinforcing bars with a superimposed portion overlapping with the one-way reinforcing bar The closed portion and the bending portion form a closed ring, and the bending portion is tightened so as to hold the rebar in the other direction without loosening by preventing the spring back by the frictional force of the overlapping portion. Connecting the reinforcing bars in the direction and the reinforcing bars in the one direction. A bending angle of the closing ring is 225 degrees;
The method for connecting unit reinforcing bars according to claim 1.

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