JPH1136601A - Reinforcement cover for placing joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for the work of removing attached concrete, to prevent settlement and cracking around vertical reinforcement, and to prevent the side wall face of a preceding lift from being contaminated with rust of the reinforcement. SOLUTION: This reinforcement cover 1 for a concrete placing joint comprises a cylindrical cover portion 3 covering the peripheral surface of reinforcement 2 and a buried portion 4 provided at the end of the cover portion 3 and buried in an upper end of concrete. The cover portion 3 and the buried portion 4 are formed integral with each other from an elastic material such as soft plastic or rubber. A cut 5 is formed in the cover portion 3 and the buried portion 4 along their material axes and is widened so that from a gap formed, the cover portion 3 and the buried portion 4 are attached to or removed from the reinforcement 2. The buried portion 4 forms a conical recess at the upper end of the concrete by being buried in the upper end of the concrete, in such a way that the recess surrounds the reinforcement 2. The buried portion 4 is provided with a step 6 at its boundary to the cover portion 3 so that the step 6 serves as the target position of the upper end of the concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced concrete covering device used at a joint portion of concrete.

[0002]

2. Description of the Related Art In rebar construction, good adhesion to concrete must be ensured by removing oils and dust attached to the peripheral surface of the rebar using a wire brush or the like in advance. Generally, it is easier to perform such cleaning work before assembling the reinforcing bars.

On the other hand, a PCCV containment vessel of a nuclear facility, L
When a tall part such as an NG tank or a pier is to be constructed, it is common practice to divide the lift into several lifts or lots in the height direction and to perform reinforced concrete work for each such lot.

[0004]

In this case, it is necessary to provide a lap joint, a press-fitting joint or a mechanical joint at the joint portion and to connect the vertical streak to the upper lift. The vertical streaks to be arranged at the top will protrude upward from the concrete top of the lift,
At the stage where the concrete placement is completed, a large amount of concrete adheres to the peripheral surface of the vertical streak.

[0005] Therefore, it takes time to remove the adhered concrete, and the work between the rebars in the forest is heavy, which places a heavy burden on the concrete worker.

[0006] Further, there has been a problem that sink cracks are likely to occur around the vertical streaks, and a problem that red rust of the reinforcing bars flows out due to rain or the like and the side wall surface of the preceding lift is contaminated.

The present invention has been made in view of the above-mentioned circumstances, and does not require the work of removing the adhered concrete, does not cause settlement cracks around the vertical streaks, and stains the side wall surface of the preceding lift with red rust of the reinforcing bars. It is an object of the present invention to provide a rebar covering tool for concrete transfer without fear.

[0008]

In order to achieve the above-mentioned object, the present invention provides a reinforcing steel covering for concrete transfer according to the present invention.
As described in the above, the covering portion covering the peripheral surface of the reinforcing bar and the buried portion provided at the end of the covering portion and buried in the concrete top are configured to be detachable from the reinforcing bar. The buried portion is formed at the top of the concrete so as to surround the reinforcing bar with a concave portion having a shape corresponding to the outer shape of the buried portion.

Further, in the rebar covering tool for concrete transfer according to the present invention, the covering portion and the buried portion are integrally formed in a tubular shape with an elastic material, and a cut along the material axis direction is formed in the covering portion and the buried portion. It is provided so that it can be attached to and detached from the rebar by opening the cut.

[0010] Further, in the rebar covering tool for concrete transfer according to the present invention, the tip of the buried portion is formed in a tapered frustoconical shape.

[0011] In addition, in the rebar covering tool for concrete transfer according to the present invention, a step is provided at a boundary between the covering portion and the buried portion.

[0012] In the rebar covering tool for concrete transfer according to the present invention, prior to placing concrete on the target lift, the boundary between the covering portion and the buried portion is aligned with the concrete top end of the lift. Attach it to the rebar and place concrete in the target lift in this state. When concrete placement is completed, remove it from the rebar and prepare for concrete placement for the next lift.

[0013] In this case, since the surrounding surface of the reinforcing bar is covered with the covering portion just above the top of the concrete during the casting of the concrete, there is no possibility that the scattered concrete adheres.

Further, since the concrete is cast in a state where the buried portion is located below the top of the concrete, the recess is formed in the top of the concrete so as to surround the reinforcing bar by removing from the reinforcing bar after placing. You. The recess prevents the concrete from sinking and cracking, and also prevents water from flowing to the side wall of the preceding lift by temporarily storing water containing red rust.

The structure, shape or material of the covering portion is arbitrary. For example, the covering portion can be formed as a cylindrical body or a rectangular cylindrical body having a reinforcing bar insertion hole formed in the center. It is also possible to attach the reinforcing bar between both sides of the reinforcing bar so that the reinforcing bar is sandwiched between the reinforcing bar and the reinforcing bar. In the case where the cover and the buried portion are formed integrally with each other in the form of a cylinder and provided with a cut along the axial direction of the material, and the cut is opened to be attached to or detached from the reinforcing bar, Even at the middle part, not at the tip, it can be easily attached to and detached from the rebar, and since it is an integral member, handling at the time of work becomes easy.

The buried portion can be formed, for example, as a cylindrical body having the same diameter as the covering portion, and may have any shape as long as it can be removed from the hardened concrete in the first place. In such a case, the concrete can be easily removed from the concrete simply by applying a twisting operation or a pulling operation.

Further, as described above, the buried portion may be formed as a cylindrical body having the same diameter as the covering portion. However, if a step is provided at the boundary with the covering portion, the step may be formed on the concrete ceiling. Since it can be set as the target position of the edge, the management of the top end at the time of placing concrete becomes easy.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an embodiment of a reinforcing steel covering for concrete transfer according to the present invention. It is to be noted that the same reference numerals are given to components and the like that are substantially the same as those in the conventional technology, and description thereof will be omitted.

(First Embodiment) FIG. 1 is an overall view of a reinforcing steel covering tool for concrete transfer according to the present embodiment. As can be seen from the figure, the reinforcing steel covering tool 1 for concrete transfer according to the present embodiment is provided at a cylindrical covering portion 3 covering the peripheral surface of the reinforcing bar 2 and at the end of the covering portion and is embedded in the concrete top. The covering portion 3 and the burying portion 4 are
It is integrally formed of an elastic material such as soft plastic or rubber.

A cut 5 is formed in the covering portion 3 and the buried portion 4 along the material axis, and the cut is widened so that the gap can be attached to and detached from the reinforcing bar 2. The height of the covering portion 3 may be appropriately determined in consideration of the possibility that fresh concrete scatters and adheres to the reinforcing bar 2, and is preferably, for example, about 10 to 20 cm.

Here, the inner diameters of the covering portion 3 and the burying portion 4 are as follows.
The outer diameter of the rebar 2 to be inserted is made slightly smaller than the outer diameter, and when the rebar 2 is attached to the rebar 2, it is firmly fixed to the peripheral surface of the rebar 2 by a restoring force that returns to the original inner diameter of the covering portion and the buried portion. It is good to be constituted so that it may be.

The buried portion 4 is buried in the concrete top to form a concave portion having a shape corresponding to the shape of an inverted truncated cone having a tapered tip, that is, a mortar-shaped concave portion.
Is formed on the top of the concrete to surround it.

The height and the degree of taper of the buried portion 4 are appropriately determined in consideration of workability at the time of pulling out from the top end of the concrete and reliability of preventing settlement cracks.

The buried part 4 is provided with a step 6 at a boundary portion with the covering part 3 so as to be a target position of the concrete top.

In order to use the rebar covering tool 1 for concrete transfer according to the present embodiment for concrete work, first, as shown in FIG. Prior to the concrete casting, the step 6 which is the boundary between the covering portion 3 and the buried portion 4 is attached to the reinforcing bar 2 so that the step 6 is aligned with the concrete top 12 of the lift. Of concrete.

Here, when a fresh concrete is dropped and a vibrator is inserted or removed, splashes of the fresh concrete scatter around, and a considerable amount of concrete adheres to the reinforcing steel bar 2 immediately above the concrete top. In the present embodiment, since the top of the concrete is covered with the covering portion 3, the concrete does not adhere to the corresponding portion of the reinforcing bar 2 at all. Note that the management of the top of the concrete may be performed based on the step 6 provided in the rebar covering tool 1 for concrete transfer.

When the concrete placing is completed, the concrete-reinforcing reinforcing-bar covering tool 1 is removed from the reinforcing bar 2 to prepare for the concrete placing of the next lift. Here, after removing the reinforcing steel covering device 1 for concrete transfer, a concave portion 14 as shown in FIG. 2B is formed at the top of the concrete so as to surround the reinforcing bar 2.

The recesses 14 prevent the subsidence cracks from being generated around the reinforcing bar 2 due to the hardening of the concrete, and when the red rust generated on the peripheral surface of the reinforcing bar 2 flows down together with rainwater, The red rust precipitates at the bottom of the recess. In addition, such red rust may be removed as required before placing concrete in the next lift.

As described above, according to the rebar covering tool 1 for concrete transfer according to the present embodiment, the surrounding surface of the rebar 2 is covered with the covering portion 3 just above the top end of the concrete during the casting of the concrete. Since it is in a state, there is no possibility that the scattered concrete adheres.

Therefore, it is not necessary to clean the peripheral surface of the reinforcing bar 2 with a wire brush or the like to remove the adhered concrete in preparation for the concrete placing of the next lift, and the burden on the concrete worker is remarkably reduced.

Also, since concrete is cast in a state where the buried portion 4 is located below the top of the concrete,
By removing from the reinforcing bar 2 after casting, the concave portion 14 is formed at the top end of the cast concrete 15 so as to surround the reinforcing bar 2.

Accordingly, there is no danger of concrete sinking and cracking occurring around the reinforcing bar 2 and the quality of the concrete at the joint surface is improved, and the red rust generated on the reinforcing bar 2 until the next concrete placement of the lift is reduced by rainwater. At the same time, there is no danger that the liquid will collect in the concave portion 14 formed at the top of the concrete and flow down along the side wall of the lift 11. Therefore, the lift 11 after removing the mold 13
Can be prevented from becoming dirty beforehand.

Further, according to the present embodiment, the covering portion 3 and the buried portion 4 are integrally formed in a cylindrical shape with an elastic material, and a cut 5 along the material axis direction is provided in the covering portion and the buried portion. So, not only at the tip of the rebar, but also at the middle,
By opening the cut, attachment to and detachment from the reinforcing bar can be easily performed, and since it is an integral member, there is no danger of loss at the work site.

Further, according to the present embodiment, since the tip of the buried portion 4 is formed in a tapered frustoconical shape, the concrete 15 can be easily taken out from the top end of the concrete 15 only by applying a twisting operation or a pulling operation.

Further, according to the present embodiment, the step 6 is provided at the boundary between the buried portion 4 and the covering portion 3, so that the step can be set as the target position of the concrete top, and Top management at the time of installation becomes easier.

In the present embodiment, the cut 5 is provided along the material axis of the covering portion 3 and the buried portion 4. However, if there is no problem in the work even if it is inserted from the end of the reinforcing bar 2, May be omitted.

In the present embodiment, the covering portion 3 is formed in a cylindrical shape, and the embedded portion 4 is formed in an inverted truncated cone shape. However, it goes without saying that these may be formed in a square shape, a pentagonal shape or the like.

In this embodiment, the step 6 is formed by projecting the buried portion 4 from the covering portion 3. However, the present invention is not limited to such a shape. ) May be used as the reinforcing steel covering 23 for transferring concrete. The covering device 23 includes a cylindrical covering portion 21 and a buried portion 22 provided at an end of the covering portion. The buried portion is formed to be tapered without protruding from the peripheral surface of the covering portion 21. It is. In this configuration, since no step is formed, the function as a mark of the top of the concrete is slightly reduced, but in other respects, substantially the same functions and effects as described above are exerted.

In this embodiment, the buried portion 4 is tapered. However, if there is no problem in taking out the concrete from the top end, it is not always necessary to form the buried portion 4 into a tapered shape.
For example, as shown in FIG. 3 (b), a concrete covering member 26 having a cylindrical covering portion 24 and a cylindrical buried portion 25 provided at an end thereof and having a larger outer diameter than the covering portion 24 may be used. . In such a configuration, substantially the same operation and effect as described above can be obtained.

FIG. 3C shows a modification in which the step is eliminated and the embedded portion is not tapered.
8 shows a concrete jointing covering tool 29 in which 8 is constituted by one cylindrical body.

In this configuration as well, the top of the concrete is managed by another means, and if there is no problem in taking out the concrete from the top of the concrete, adhesion of the concrete, outflow of red rust and cracking of the settlement are prevented. In this respect, substantially the same operation and effect as those of the above-described embodiment can be obtained.

In this embodiment or the above-described modified example, a circular insertion hole is formed in the covering portion and the buried portion, regardless of whether the cut 5 is provided or not, and a reinforcing bar is fitted into the insertion hole. However, instead of this, it is also possible to use a split type rebar covering tool for concrete transfer as shown in FIG.

The reinforcing steel covering tool 31 for transferring concrete shown in FIG. 3 comprises a male member 31a and a female member 31b, and has a covering portion 32 in which a cylindrical body is vertically divided in half, and an inverted cone provided at the end thereof. It is composed of a trapezoidal buried portion 33, and a locking piece 34 is protruded from the buried portion 33 of the male member 31a.
In the buried portion 33 of the female member 31b, a locking recess 35 to be locked by the locking piece is formed.

In this configuration, the male member 31a and the female member 31b are sandwiched between the reinforcing bars 2 in FIG.
At this time, the locking piece 34 protruding from the buried portion 33 of the male member 31a is fitted into the locking recess 35 formed in the buried portion 33 of the female member 31b. To fix both. Note that the operation and effect of this modified example are substantially the same as those of the above-described embodiment, and thus description thereof is omitted here.

[0045]

As described above, according to the first embodiment of the present invention, it is necessary to remove the adhered concrete by cleaning the peripheral surface of the reinforcing bar with a wire brush or the like. And the burden on concrete workers is significantly reduced. In addition, since the concave portion is formed at the top end of the cast concrete so as to surround the reinforcing bar, there is no possibility that the concrete will sink and crack.
The quality of the concrete at the joint surface is improved, and the red rust generated on the reinforcing steel can be prevented from flowing down along with the rainwater along the side wall of the previously cast portion.

According to the second aspect of the present invention, even when the reinforcing bar is not at the tip but at an intermediate portion, it can be easily attached to and removed from the reinforcing bar. In addition, since it is an integral member, there is also an effect that there is no risk of loss at the work site.

Further, according to the third aspect of the present invention, there is provided an effect that the concrete can be easily removed from the concrete simply by applying a twisting operation or a tensioning operation.

Further, according to the fourth aspect of the present invention, it is possible to set the step to the target position of the concrete top, and to manage the top when concrete is poured. It also has the effect of becoming easier.

[0049]

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall view of a reinforcing steel covering tool for concrete transfer according to the present embodiment, (a) is a perspective view, and (b) is a side view showing a part of the section.

FIGS. 2A and 2B are side views showing a use condition of a reinforcing steel covering tool for concrete transfer according to the present embodiment, wherein FIG. 2A shows a state in which the covering tool is attached to a reinforcing bar, and FIG. The state of each was shown.

FIG. 3 is a vertical cross-sectional view showing a rebar covering tool for concrete transfer according to a modification.

FIGS. 4A and 4B are diagrams showing a reinforcing rod covering for concrete transfer according to another modification, in which FIG. 4A is an exploded sectional view and FIG. 4B is a sectional view along line AA.

[Explanation of symbols]

1, 23, 26, 29, 31 Reinforcing bar covering for concrete transfer 2 Reinforcing bar 3, 21, 24, 27, 32 Covering portion 4, 22, 25, 28, 33 Embedding portion 5 Cut 6 Step 12 Concrete top 14 Recess

Claims (4)

[Claims] 1. A covering portion for covering a peripheral surface of a reinforcing bar and a buried portion provided at an end of the covering portion and buried in a concrete top are configured to be detachable from the reinforcing bar,
The embedding portion is formed on a concrete top end so as to form a concave portion having a shape corresponding to the outer shape of the embedding portion so as to surround the reinforcing bar. 2. The rebar according to claim 1, wherein said covering portion and said buried portion are integrally formed in a cylindrical shape with an elastic material, and said covering portion and said buried portion are provided with cuts along a material axis direction. The rebar covering tool for concrete transfer according to claim 1, wherein the rebar covering is detachable from the concrete. 3. The reinforcing steel covering device for concrete transfer according to claim 1, wherein a tip of the buried portion is formed in a tapered frustoconical shape. 4. The reinforcer for concrete reinforcement according to claim 1, wherein a step is provided at a boundary between the covering portion and the buried portion.