JP7037996B2 - How to assemble slab rebar - Google Patents

Description

The present invention relates to a method for assembling slab reinforcing bars used for constructing a slab-shaped reinforced concrete structure.

So-called slab rebars such as bottom slabs and top slabs are shears that connect the lower main rebar arranged in a plane, the upper main rebar arranged in a plane above it, and the upper main rebar and the lower main rebar. Includes reinforcing bars. In the shear reinforcing bar, the hooks (fixing portions) at both ends are the upper main bar (specifically, the upper bar, which is also referred to as "upper bar") and the lower main bar (specifically, the lower bar, this). Is arranged in the vertical direction so as to be caught by the "lower rebar"). The hooks include semi-circular hooks, acute-angled hooks, and L-shaped hooks according to the standard.

The general method for assembling slab reinforcing bars is as follows.
1) Place a spacer that regulates the cover thickness on the floor surface (leveling controller, floor formwork, etc.).
2) Assemble the lower main reinforcing bar (lattice reinforcement) on the spacer.
3) Place a receiving metal fitting (frame, assembly bar, etc.) for assembling the upper main rebar on the lower main rebar.
4) Assemble the upper main reinforcing bar (lattice reinforcement) on the receiving metal fitting.
5) The shear reinforcing rebar is dropped into the gap between the upper main rebar and the lower main rebar, and bound and fixed to the upper main rebar and the lower main rebar with a wire or the like.

In the case of the above assembly method, since the distance between the upper main rebar and the lower main rebar is fixed, as a shear reinforcing rebar, shear reinforcement having semicircular hooks at both ends as shown in FIG. 6A. The use of rebar is difficult. The same applies to the shear reinforcing reinforcing bar having acute angle hooks at both ends as shown in FIG. 6 (b).

Therefore, the following shear reinforcing bars are used (see the reference diagram in FIG. 7).
(B) Nikoichi (two reinforcing bars with semi-circular hooks on both ends are connected by a lap joint)
Hook the upper semi-circular hook of one rebar to the upper main rebar, hook the lower semi-circular hook of the other rebar to the lower main rebar, and then lap the two rebars in the vertical middle of the slab. Connect and fix with.
(B) Semi-circular hook + fixing plate (one with a semi-circular hook at one end and a fixing plate at the other end)
After hooking the semi-circular hook on the upper main reinforcing bar, position the fixing plate on the lower side of the lower main reinforcing bar and bind it with a wire or the like.
(C) Semi-circular hook + L-shaped hook (one with a semi-circular hook at one end and an L-shaped hook at the other end)
After hooking the semi-circular hook on the upper or lower main reinforcing bar, the L-shaped hook is pulled into the opposite main reinforcing bar and tied with a wire or the like. In this case, it is common to switch the top and bottom alternately.

Further, Patent Document 1 discloses the following method of assembling a slab reinforcing bar using a shear reinforcing reinforcing bar having semicircular hooks at both ends.
1) Build the lower main reinforcing bar.
2) Arrange the shear reinforcing bar so that the lower hook of the shear reinforcing bar having semicircular hooks at both ends engages with the lower main reinforcing bar.
3) Temporarily place the lower reinforcing bar of the upper main reinforcing bar on the lower main reinforcing bar.
4) Arrange the upper reinforcing bar of the upper main reinforcing bar so as to engage with the upper hook of the shear reinforcing reinforcing bar, and fix it with a fixative.
5) Pull up the lower bar of the temporarily placed upper main bar and fix it to the upper bar of the upper main bar.

Japanese Unexamined Patent Publication No. 11-044046

The above (a) to (c) have the following problems.
(A) Nikoichi needs to use two semi-circular hook reinforcing bars at both ends as a lap joint of 40d (d: reinforcing bar diameter), which increases the amount of reinforcing bars.
In addition, a worker enters between the upper main reinforcing bar and the lower main reinforcing bar to bundle and bind the two reinforcing bars, which is troublesome.
In addition, it is difficult to form a lap joint in a straight line with two reinforcing bars, and it is necessary to bind two or more of the lap joint portions with a number wire or the like.

(B) The semi-circular hook + fixing plate is easy to install, but it costs a lot to make it a fixing plate.

(C) Since the fixing performance of the semi-circular hook + L-shaped hook is inferior to that of the semi-circular hook, the semi-circular hooks must be arranged so that the semi-circular hooks alternate up and down.
Further, after the semi-circular hook is hooked on the upper bar of the upper main bar, the L-shaped hook is hooked on the lower bar through the gap of the lower main bar, which is not possible on the drawing. Actually, it is necessary to make the pitch of the lower main reinforcing bar larger than the drawing, temporarily arrange it, arrange the L-shaped hook, and then return the lower main reinforcing bar to the normal position.

In the assembly method described in Patent Document 1, since the upper main reinforcing bar is assembled after the shear reinforcing reinforcing bar is arranged, the assembly of the upper main reinforcing bar becomes complicated, and the shear reinforcing reinforcing bar is fixed exclusively for fixing and preventing the fall. You will need the ingredients.

The present invention has been made in view of such an actual situation, and is a slab reinforcing bar that can be relatively easily assembled by using a shear reinforcing reinforcing bar having semicircular hooks (or sharp angle hooks) at both ends having excellent fixing properties. It is an object to provide an assembling method of.

The first and second assembly methods of the slab reinforcing bar according to the present invention include the following steps 1) to 4).
1) A step of installing a temporary spacer higher than the main spacer that regulates the cover thickness and constructing the lower main reinforcing bar on the temporary spacer. 3) Step of constructing the upper main reinforcing bar 3) A step of using a shear reinforcing reinforcing bar having semicircular hooks at both ends, hooking the upper hook on the upper main reinforcing bar, and inserting the lower hook into the gap of the lower main reinforcing bar. 4) A step of removing the temporary spacer, moving the lower main reinforcing bar downward, engaging the lower main reinforcing bar with the lower hook, and replacing the lower main reinforcing bar with the main spacer.

In the first and second assembly methods, the temporary spacer can adjust the height of receiving the lower main reinforcing bar, and by adjusting the height lower, the lower main reinforcing bar is moved downward. ..
In the first assembly method, the temporary spacer moves the lower main reinforcing bar downward and also serves as the main spacer.
In the second assembly method, the temporary spacer includes a pair of receiving members and a tightening member for tightening them in the horizontal direction, and the facing distance of the pair of receiving members can be adjusted.

In the first and second assembly methods, instead of the shear reinforcing bars having semicircular hooks at both ends, shear reinforcing bars having acute angle hooks at both ends can be used. However, the fixing performance is slightly inferior.

According to the present invention, it is possible to use a shear reinforcing bar with semicircular hooks on both ends, which is excellent in fixing performance, and it is possible to carry out the reinforcement relatively easily.

The figure which shows the example of the object structure which uses the slab reinforcing bar The figure which shows the structural example of a slab reinforcing bar The figure which shows the 1st Embodiment of the assembly method of a slab reinforcing bar. The figure which shows the concrete structural example of a temporary spacer The figure which shows the 2nd Embodiment of the assembly method of a slab reinforcing bar Explanatory drawing of semi-circular hook and acute angle hook Reference diagram of the conventional example

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 shows an example of a target structure using slab reinforcing bars. This is an example of a road tunnel, which is composed of reinforced concrete such as a top slab 101, a bottom slab 102, a side wall 103, and a middle wall 104, and can be constructed by assembling reinforcing bars in the skeleton and placing concrete in the skeleton.

FIG. 2 shows a general configuration example of a slab reinforcing bar, in which the lower main reinforcing bar 1 formed by crossing the axial reinforcing bar 1a and the axially orthogonal reinforcing bar 1b and combining them in a grid pattern, and similarly the axial reinforcing bar 2a and the shaft. It consists of an upper main reinforcing bar 2 formed by crossing the direction perpendicular reinforcing bars 2b and combining them in a grid pattern, and a shear reinforcing reinforcing bar 3 connecting the lower main reinforcing bar 1 and the upper main reinforcing bar 2. It is assembled by connecting with fixing brackets. The concrete is placed on the lower main reinforcing bar 1 and the upper main reinforcing bar 2 with a predetermined cover thickness K.
In the case of a circular slab reinforcing bar, the lower main reinforcing bar 1 and the upper main reinforcing bar 2 are constructed by combining radial reinforcing bars and circumferential reinforcing bars, respectively.

FIG. 3 shows a first embodiment of a method for assembling a slab reinforcing bar.
In FIG. 3A, as a first step, a main spacer 11 made of, for example, a mortar block having a height that defines a cover thickness K on a floor surface (leveling controller, floor formwork, etc.) 10 and a book. A temporary spacer 12 higher than the setting spacer 11 is arranged. The temporary spacer 12 is set higher than the main spacer 11 by 6.5 d (d: shear reinforcing bar diameter) or more.
Then, on the temporary spacer 12, the axial rebar 1a and the axial right rebar 1b are crossed and combined in a grid pattern. In this example, the axial right rebar 1b is combined with the lower rebar (lower rebar) and the axial rebar 1a. As the upper reinforcing bar, the lower main reinforcing bar 1 is constructed. Therefore, the lower main reinforcing bar 1 is constructed at a position higher than the normal position (position shown in FIG. 2) by 6.5d or more.

In FIG. 3B, as a second step, a receiving metal fitting (frame or assembling bar) 13 for assembling the upper main reinforcing bar is installed on the floor surface 10. As the receiving metal fitting 13, in the case of a large slab, a frame made of L-shaped steel or the like is used, and in the case of a small slab (reinforcing bar diameter is small), a reinforcing bar called an assembly bar, a width retaining bar or a setup bar is used.
Then, on the receiving metal fitting 13, the axial reinforcing bar 2a and the axial right angle reinforcing bar 2b are crossed and combined in a grid pattern. In this example, the axial reinforcing bar 2a is the lower reinforcing bar and the axial right angle reinforcing bar 2b is the upper reinforcing bar (upper). As a reinforcing bar), the upper main reinforcing bar 2 is constructed. Therefore, the upper main reinforcing bar 2 is constructed at a regular position, but the lower main reinforcing bar 1 is constructed at a position higher than the regular position, so that the upper main reinforcing bar 2 and the lower main reinforcing bar 1 are constructed. The interval is narrower than the regular interval (S in FIG. 2).

In FIG. 3C, as a third step, a shear reinforcing bar 3 having semicircular hooks at both ends is incorporated. That is, the upper hook 3a of the shear reinforcing reinforcing bar 3 is hooked on the upper main reinforcing bar 2 (specifically, the upper reinforcing bar thereof), and the lower hook 3b is inserted into the gap of the lower main reinforcing bar 1. At this time, the lower hook 3b is located lower than the lower main reinforcing bar 1.

In FIG. 3D, as the fourth step, the temporary spacer 12 is removed, the lower main reinforcing bar 1 is moved downward, and the lower main reinforcing bar 1 (specifically, the lower lower reinforcing bar) is sheared and reinforced. It is engaged with the lower hook 3b and replaced with the main spacer 11.

Specifically, first, the lower main reinforcing bar 1 is once lifted by a crane (not shown), a gap is created between the temporary spacer 12 and the lower main reinforcing bar 1, and the temporary spacer 12 is removed.
After removing the temporary spacer 12, the lower main reinforcing bar 1 is suspended by a crane. By suspending, the lower main reinforcing bar 1 engages with the lower hook 3b of the shear reinforcing reinforcing bar 3, and at the same time, it is lowered onto the main spacer 11 and the load of the lower main reinforcing bar 1 is received by the main spacer 11. ..

The lifting and lowering of the lower main reinforcing bar 1 with the crane here does not need to be performed collectively for the entire surface of the lower main reinforcing bar 1, and the rigidity of the lower main reinforcing bar 1 is small (when the reinforcing bar diameter is small). ) May be partially lifted and lowered, and gradually transferred from the temporary spacer 12 to the main spacer 11.
Further, using a jack instead of a crane, the lower main reinforcing bar 1 is supported from the lower side in small sections, the lower main reinforcing bar 1 is lifted in small sections, and the temporary spacer 12 is removed while the main spacer 11 position. You may lower it to.

After that, the lower main reinforcing bar 1 and the shear reinforcing reinforcing bar 3 are fixed by welding, wire bundling, fixing metal fittings, or the like.
The upper main reinforcing bar 2 and the shear reinforcing reinforcing bar 3 may be fixed at any timing as long as the upper hook 3a of the shear reinforcing reinforcing bar 3 is hooked on the upper main reinforcing bar 2. It may be performed at the same time as fixing with the shear reinforcing reinforcing bar 3. However, if they are performed at the same time, the shear reinforcing bars 3 are loosely bound (temporarily bound) so that the lower main reinforcing bars 1 are surely inserted into the lower hook 3b when the lower main reinforcing bars 1 are moved downward. It is good to leave it.

In the present embodiment, the main spacer 11 and the temporary spacer 12 are arranged separately, but for the temporary spacer 12, the shaped steel having a height of 6.5 d or more is removed on the main spacer 11. It may be realized by placing it as possible.

Next, an improved example of the temporary spacer 12 will be described with reference to FIG.
FIG. 4 shows a specific configuration example of the temporary spacer.
The temporary spacer 12 is composed of, for example, a pair of receiving members 21 and 22 made of concrete blocks placed on the floor surface 10, and bolts 23 and nuts 24 as tightening members for horizontally tightening them.

Each of the receiving members 21 and 22 has inclined surfaces 21a and 22a at the upper ends thereof, respectively. The pair of receiving members 21 and 22 face each other with the inclined surfaces 21a and 22a to form a V-shaped groove formed by the inclined surfaces 21a and 22a in a tightened state by the bolts 23 and nuts 24. This V-shaped groove receives the lower lower reinforcing bar (in this example, the axially perpendicular reinforcing bar 1b) at a position deviating from the intersection of the lower main reinforcing bar 1, and functions as a temporary spacer.

From the state of functioning as a temporary spacer as shown in FIG. 4A, when the nut 24 is loosened and the distance between the head of the bolt 23 and the nut 24 is increased as shown in FIG. 4B, the inclined surface is increased. The lower main reinforcing bar 1 can be gradually lowered by using the 21a and 22a. Finally, as shown in FIG. 4B, the position where the lower main reinforcing bar 1 (specifically, the lower lower reinforcing bar) engages with the shaft portion of the bolt 23 between the pair of receiving members 21 and 22. Up to, the lower main reinforcing bar 1 can be lowered and received.
Therefore, by setting the position of the bolt 23 to the height position of the main spacer, the bolt 23 can function as the main spacer.

The height of the temporary spacer 12 of FIG. 4 for receiving the lower main reinforcing bar 1 can be adjusted, and by adjusting the height to a lower height, the lower main reinforcing bar 1 can be moved downward. Therefore, it is possible to move the lower main reinforcing bar 1 downward without using a crane, a jack, or the like. However, it may be used in combination with a crane, a jack, or the like.

Further, the temporary spacer 12 in FIG. 4 can move the lower main reinforcing bar 1 downward and also serve as the main spacer (11). That is, when the pair of receiving members 21 and 22 are brought close to each other, the pair of receiving members 21 and 22 function as temporary spacers, and when the pair of receiving members 21 and 22 are separated from each other, the pair of receiving members 21 and 22 are separated. The bolt 23 in between functions as a permanent spacer. This makes it possible to reduce the number of members used.

However, the temporary spacer 12 shown in FIG. 4 may not be used as the main spacer, but may be used as the temporary spacer (temporary material). In this case, the position of the bolt 23 is set lower than the height position of the main spacer. This has the advantage that the temporary spacer 12 can be removed without lifting the lower main reinforcing bar 1, and can be reused (reused) after removal.

FIG. 5 shows a second embodiment of a method for assembling slab reinforcing bars.
In FIG. 5A, as a first step, a spacer 11 made of, for example, a mortar block having a height defining a cover thickness K is arranged on the floor surface (leveling container, floor formwork, etc.) 10.
Then, on the spacer 11, the axial rebar 1a and the axial right rebar 1b are crossed and combined in a grid pattern. In this example, the axial right rebar 1b is the lower bar (lower lower bar) and the axial rebar 1a is the upper side. As a reinforcing bar, the lower main reinforcing bar 1 is constructed. Therefore, the lower main reinforcing bar 1 is constructed at a regular position (position shown in FIG. 2).

In FIG. 5B, as a second step, a receiving metal fitting (frame or assembly bar) 14 for assembling the upper main rebar is installed on the lower main rebar 1 at a position lower than the regular position. Then, on the receiving metal fitting 13, the axial reinforcing bar 2a and the axial right angle reinforcing bar 2b are crossed and combined in a grid pattern. In this example, the axial reinforcing bar 2a is the lower reinforcing bar and the axial right angle reinforcing bar 2b is the upper reinforcing bar (upper). As a reinforcing bar), the upper main reinforcing bar 2 is constructed. Therefore, the upper main rebar 2 is constructed at a position lower than the normal position (position shown in FIG. 2), and the distance between the upper main rebar 2 and the lower main rebar 1 is the regular distance (S in FIG. 2). It becomes narrower.

In FIG. 5C, as a third step, a shear reinforcing bar 3 having semicircular hooks at both ends is incorporated. That is, the upper hook 3a of the shear reinforcing reinforcing bar 3 is hooked on the upper main reinforcing bar 2 (specifically, the upper reinforcing bar thereof), and the lower hook 3b is inserted into the gap of the lower main reinforcing bar 1. At this time, the lower hook 3b is located lower than the lower main reinforcing bar 1.

In FIG. 5D, as the fourth step, the upper main reinforcing bar 2 is moved upward together with the shear reinforcing reinforcing bar 3, and the lower hook 3b of the shear reinforcing reinforcing bar 3 is moved to the lower main reinforcing bar 1 (specifically, its). Engage with the lower rebar).
Then, as a fifth step, with the upper main reinforcing bar 2 moved upward, the receiving metal fitting 14 is extended in the height direction, and the upper main reinforcing bar 2 is received at the extended portion.

The movement of the upper main reinforcing bar 2 here can be performed by lifting the upper main reinforcing bar 2 with a crane (not shown) or by lifting the upper main reinforcing bar 2 with a jack (not shown). can.

The extension of the receiving metal fitting 14 here can be realized by incorporating an extension mechanism into the receiving metal fitting 14, but simply, as shown in FIG. 5D, the receiving metal fitting 14 and the upper main reinforcing bar 2 are extended. It can be realized by inserting (biting) an appropriate piece material (for example, an iron ingot) 15 between the and, and fixing it as appropriate.
Further, the upper main reinforcing bar 2 may be moved all at once, but the upper main reinforcing bar 2 may be moved sequentially for each small section, and the piece material 15 may be inserted in each moved section.

The hooks 3a and 3b at both ends of the shear reinforcing reinforcing bar 3 and the upper main reinforcing bar 2 and the lower main reinforcing bar 1 are bound by a number wire or the like. The timing is the same as that of the first embodiment.

Next, a case of constructing a slab reinforcing bar such as the side wall 103 and the middle wall 104 of FIG. 1 will be described.
In this case, as prefabricated processing, the reinforcing bars of the side wall and the inner wall may be assembled in a sideways state. That is, as in the above embodiment, after constructing a slab reinforcing bar (reinforcing bar cage) using the lower main reinforcing bar, the upper main reinforcing bar, and the shear reinforcing reinforcing bar, the slab reinforcing bar (reinforcing bar cage) is erected by a crane or the like and suspended at a predetermined position. You just have to put it in.
Therefore, the present invention can also be applied to prefabricated processing as a reinforcing bar cage such as a side wall reinforcing bar.

In addition, the illustrated embodiment is merely an example of the present invention, and the present invention includes various improvements and improvements made by those skilled in the art within the scope of the claims, in addition to those directly shown by the described embodiments. It goes without saying that it involves changes.
The claims at the time of filing were as follows.
[Claim 1]
A process of installing a temporary spacer higher than the main spacer that regulates the cover thickness and constructing the lower main reinforcing bar on the temporary spacer.
The process of installing the receiving metal fittings for assembling the upper main reinforcing bar and constructing the upper main reinforcing bar on the receiving metal fittings,
A step of using a shear reinforcing bar having semi-circular hooks at both ends, hooking the upper hook on the upper main bar, and inserting the lower hook into the gap of the lower main bar.
A step of removing the temporary spacer, moving the lower main reinforcing bar downward, engaging the lower main reinforcing bar with the lower hook, and replacing the lower main reinforcing bar with the main spacer.
How to assemble slab rebar, including.
[Claim 2]
The method for assembling a slab reinforcing bar according to claim 1, wherein the lower main reinforcing bar is once moved upward when the temporary spacer is removed.
[Claim 3]
1. Item 2. The method for assembling the slab reinforcing bar according to Item 2.
[Claim 4]
The method for assembling a slab reinforcing bar according to claim 3, wherein the temporary spacer moves the lower main reinforcing bar downward and also serves as the main spacer.
[Claim 5]
3. The method of assembling the slab reinforcing bar described.
[Claim 6]
When the pair of receiving members are brought close to each other, the pair of receiving members function as the temporary spacer, and when the pair of receiving members are separated from each other, the tightening member between the pair of receiving members is said. The method for assembling a slab reinforcing bar according to claim 5, wherein the slab rebar functions as a permanent spacer.
[Claim 7]
The process of constructing the lower main reinforcing bar on the spacer that regulates the cover thickness,
The process of installing the receiving bracket for assembling the upper main reinforcing bar lower than the regular position and constructing the upper main reinforcing bar on the receiving bracket,
A step of using a shear reinforcing bar having semi-circular hooks at both ends, hooking the upper hook on the upper main bar, and inserting the lower hook into the gap of the lower main bar.
A step of moving the upper main rebar upward with the shear reinforcing rebar and engaging the lower hook of the shear reinforcing rebar with the lower main rebar.
A step of extending the receiving metal fitting in the height direction with the upper main reinforcing bar moved upward and receiving the upper main reinforcing bar at the extended portion.
How to assemble slab rebar, including.
[Claim 8]
The method for assembling a slab reinforcing bar according to claim 7, wherein the extension of the receiving metal fitting is performed by inserting and arranging a piece material between the receiving metal fitting and the upper main reinforcing bar.
[Claim 9]
The slab reinforcing bar according to any one of claims 1 to 8, wherein a shear reinforcing bar having acute angle hooks at both ends is used instead of the shear reinforcing bar having semicircular hooks at both ends. Assembly method.

1 Lower main reinforcing bar (1a axial reinforcing bar, 1b axial right angle reinforcing bar)
2 Upper main reinforcing bar (2a axial reinforcing bar, 2b axial right angle reinforcing bar)
3 Shear reinforcement rebar (with semi-circular hooks on both ends)
3a Upper hook 3b Lower hook 10 Floor surface 11 Spacer (main spacer)
12 Temporary spacer 13 Receiving metal fittings 14 Receiving metal fittings 15 Piece materials 21, 22 Receiving members 23 Bolts 24 Nuts

Claims (6)

A process of installing a temporary spacer higher than the main spacer that regulates the cover thickness and constructing the lower main reinforcing bar on the temporary spacer.
The process of installing the receiving metal fittings for assembling the upper main reinforcing bar and constructing the upper main reinforcing bar on the receiving metal fittings,
A step of using a shear reinforcing bar having semi-circular hooks at both ends, hooking the upper hook on the upper main bar, and inserting the lower hook into the gap of the lower main bar.
A step of removing the temporary spacer, moving the lower main reinforcing bar downward, engaging the lower main reinforcing bar with the lower hook, and replacing the lower main reinforcing bar with the main spacer.
Is a method of assembling slab reinforcing bars, including
The height of the temporary spacer can be adjusted to receive the lower main reinforcing bar, and by adjusting the height to a lower height, the lower main reinforcing bar can be moved downward.
The temporary spacer is a method for assembling a slab reinforcing bar, which moves the lower main reinforcing bar downward and also serves as the main spacer. The method for assembling a slab reinforcing bar according to claim 1, wherein the temporary spacer includes a pair of receiving members and a tightening member for tightening them in the horizontal direction, and the facing distance between the pair of receiving members can be adjusted. A process of installing a temporary spacer higher than the main spacer that regulates the cover thickness and constructing the lower main reinforcing bar on the temporary spacer.
The process of installing the receiving metal fittings for assembling the upper main reinforcing bar and constructing the upper main reinforcing bar on the receiving metal fittings,
A step of using a shear reinforcing bar having semi-circular hooks at both ends, hooking the upper hook on the upper main bar, and inserting the lower hook into the gap of the lower main bar.
A step of removing the temporary spacer, moving the lower main reinforcing bar downward, engaging the lower main reinforcing bar with the lower hook, and replacing the lower main reinforcing bar with the main spacer.
Is a method of assembling slab reinforcing bars, including
The height of the temporary spacer can be adjusted to receive the lower main reinforcing bar, and by adjusting the height to a lower height, the lower main reinforcing bar can be moved downward.
A method for assembling a slab reinforcing bar, wherein the temporary spacer includes a pair of receiving members and a tightening member for tightening them in a horizontal direction, and the facing distance between the pair of receiving members can be adjusted. When the pair of receiving members are brought close to each other, the pair of receiving members function as the temporary spacer, and when the pair of receiving members are separated from each other, the tightening member between the pair of receiving members is said. The method for assembling a slab reinforcing bar according to claim 2 or 3, which functions as a permanent spacer. The method for assembling a slab reinforcing bar according to any one of claims 1 to 4 , wherein the lower main reinforcing bar is temporarily moved upward when the temporary spacer is removed. The method for assembling a slab reinforcing bar according to any one of claims 1 to 5 , wherein a shear reinforcing bar having acute angle hooks at both ends is used instead of the shear reinforcing bar having semicircular hooks at both ends.

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