JP2003268974A - Sleeve for forming through-hole in case of concrete placing and method for forming through-hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cut down a cost by the reduction of a working cost and the substantial reduction of a sleeve cost by shortening workhours and enabling a large number of recyclings by decreasing the frequency of scrap treatments on the assumption that through-holes for a wiring and piping are adapted to the conditions of a fire-resisting partition wall and a slab when the through-holes are formed by using a sleeve in the case of the construction of a concrete wall and a floor slab. <P>SOLUTION: In a method in which the through-hole is formed in the case of the execution of works of the concrete wall or a floor, at least one end of the external-surface tapered polyethylene sleeve 1 having a fixed draft is fixed onto the internal surface of forms 2a and concrete 4 is placed, the forms are removed, the polyethylene sleeve 1 is extracted and the extracted sleeve 1 is reused in the case of the next execution of works. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sleeve used when forming a through hole for wiring and piping when a concrete wall or beam or a floor slab is constructed, and a method of forming a through hole during concrete pouring. Is.

[0002]

2. Description of the Related Art When constructing a concrete wall or floor slab of a building, a through hole for wiring and piping is formed at the time of placing concrete, and a wiring pipe and a pipe are pierced at a proper time after the construction. The gap between the pipe and the tube is sealed with fireproof putty. Conventionally, in order to form this through-hole, a sleeve is arranged at a place where the through-hole is to be formed before placing concrete, and after that, concrete is placed and cured, and the sleeve hole is used as the through-hole. There is. The sleeve is made of hard paper, vinyl chloride resin or steel plate.

[0003]

However, if the material is made of combustible hard paper or vinyl chloride resin, it lacks fire resistance. To make a fireproof partition wall or slab, peel off the sleeve after placing concrete. It is necessary to. However, the paper sleeve has a small strength, and even though the vinyl chloride resin sleeve has a certain level of strength, it has a large adhesive strength with concrete and requires a large peeling force,
In any of the sleeves, the sleeve is inevitably ruptured at the time of peeling and removed, and cannot be reused. Therefore, it is unavoidable that it is a single-use disposable item, and it is expensive after all.
In contrast to these hard paper sleeves and vinyl chloride resin sleeves, steel plate sleeves are non-flammable and do not hinder the fire protection partition walls and slabs, but have high adhesive strength with concrete and It is extremely difficult to use, and is extremely expensive in combination with the high cost of the material itself.

Further, in the conventional sleeve, when a through hole is formed at the time of construction of a concrete wall, the raw pipe (the length is usually about 2 meters) is cut into a predetermined length according to the thickness of the wall, Attach a plurality of plastic or metal ears to the outer circumference of both ends of the cut at approximately equal intervals with adhesive tape, wire, etc., place the sleeve at a predetermined position through the gap of the bar arrangement, and Each ear is fixed to the inner surface of the mold with a nail, and it takes a considerable amount of time for dimensioning and mounting of the ear.
There is a risk that the hand may be injured when cutting, the work is troublesome, and the work cost is high. Further, due to the weight of the poured concrete, the sleeve end may be detached from the mold inner surface fixing ear, and the sleeve may be flattened due to the weight of the poured concrete, so that it is often impossible to form the circular hole.

Therefore, as shown in FIG. 14 (a), the fixture 111a 'is fixed to the inner surface of one of the molds 2a' by the spike 113 'on the back face of the fixture, and the fixture 111 is fixed.
b'is fixed to the inner surface of the other mold 2b 'by a spike 113' on the rear surface of the fixture, and the sleeve 1'is expanded and contracted as shown in (b) of FIG.
b ′), and as shown in FIG. 14C, the length of this double pipe is adjusted according to the thickness w of the beam due to its elasticity, and one end of one sleeve piece 1a ′ is attached to one. Ingredient 1
It has been proposed that the other end of the other sleeve piece 1b 'be fitted to the other fitting 11b' and the other fitting 111b '(Patent No. 2877866).

However, even in this double sleeve, (1) if it is made of hard paper or vinyl chloride resin, it is necessary to peel and remove it in order to satisfy the condition of the fireproof partition wall. Inevitable, scrap processing of the sleeve is required, and further, the problem of taking away the broken pieces adhering to the concrete and reusing it still remains. (2) With steel plates, fire resistance Although it does not impair the performance of the fireproof partition wall even if it is left unattended, the problem that it is extremely difficult to reuse and it is extremely expensive has not been solved.

The object of the present invention is to presuppose that when a sleeve is used to form a through hole for wiring / piping when a concrete wall or floor slab is constructed, it is adapted to the conditions of a fireproof partition wall / slab, The work time can be shortened, the frequency of scrap processing can be remarkably reduced, and a large number of times can be recycled, thereby achieving a dramatic cost reduction by reducing the work cost and substantially reducing the sleeve cost.

[0008]

According to a first aspect of the present invention, there is provided a through hole forming sleeve for pouring concrete, which is inserted when pouring concrete on a concrete wall, a beam or a floor, and is removed after removing the formwork. Is a sleeve used to form a concrete, which is hard to adhere to concrete and has an outer tapered surface having a draft. In the third aspect, it is made of polyethylene, and in the fourth aspect, the release layer is provided on the surface of the sleeve core body.

According to a fifth aspect of the present invention, there is provided a through hole forming sleeve for pouring concrete, wherein the sleeve wall thickness is increased toward the large diameter end side in the sleeve of the first to fourth aspects.

A method of forming a through hole at the time of placing concrete according to claim 6 is a method of forming a through hole at the time of constructing a concrete wall, a beam, or a floor.
5 At least one end of any of the through hole forming sleeves is fixed to the inner surface of the formwork, concrete is poured into the formwork, the formwork is removed, the sleeve is removed, and the removed sleeve is re-used for the next construction. It is characterized by being used.

A method of forming a through hole at the time of pouring concrete according to a seventh aspect is characterized in that the sleeve for forming a through hole can be telescopically expanded and contracted.

According to an eighth aspect of the present invention, there is provided a method of forming a through hole during concrete pouring, in which at least one end of the through hole forming sleeve is fixed to the inner surface of the mold by attaching a core member to the inner surface of the mold. At least one end of the sleeve is inserted into the member.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a through-hole forming sleeve in a concrete wall or the like according to the present invention, which is made of a synthetic resin that is difficult to adhere to concrete, for example, polyethylene, and has a tapered outer surface for imparting a predetermined draft. Further, the wall thickness is increased to the one end side fixed to the mold 2a, and t1> t2.
Further, the outer diameter at the small-diameter end is made smaller than the inner diameter at the large-diameter end so that stacking is possible. In place of polyethylene, a metal or hard vinyl chloride resin sleeve core is provided with a release layer on the surface thereof, for example, a winding layer of a release film such as a polyethylene film or a coating layer of a silicone release agent. It can also be used.

FIGS. 2A to 2C show a method of forming a through hole in a concrete wall or the like by using the sleeve according to the present invention. In FIG. 2B, the reinforcing bar 3 is arranged,
The figure shows a stage in which the polyethylene sleeve 1 is arranged at a predetermined position, concrete 4 is formed, the curing and hardening of the cast concrete is completed, and the molds 2a and 2b are removed. After that, by applying a pulling force to the polyethylene sleeve 1, for example, the other end of the sleeve is tapped with a mallet 5 as shown in FIG. 2B, and the polyethylene sleeve is provided as shown in FIG. 1 is extracted, and a through hole h is formed in the extraction trace.

The polyethylene sleeve 1 thus extracted is collected and reused for the next construction.

Polyethylene, which is the material of the sleeve, is non-polar in molecular structure and has weak adhesive force. Moreover, due to the draft, the pulling force can be made sufficiently small, and the sleeve damage due to pulling out is only that much. It can be suppressed mildly, and the number of times of reuse described above can be increased.

In the above, it is also possible to apply a release agent or a lubricant to the outer surface of the sleeve. In this case, the withdrawal force can be further reduced, and the sleeve damage due to the withdrawal can be further suppressed. The number of times of reuse described above can be further increased.

During the above-mentioned construction, the weight of the poured concrete acts on the polyethylene sleeve, and particularly in the case of wall construction, the bending moment acting on the polyethylene sleeve due to the weight of the concrete becomes maximum at the fixed end on the formwork side. However, in the above embodiment, since the wall thickness of the sleeve is maximum at the mold frame side fixed end, deformation at the mold frame side fixed end can be well suppressed and the fixed state can be stably held,
The flattening of the sleeve can be effectively prevented.

The larger the draft angle of the polyethylene sleeve, the smaller the pulling force required for pulling out the sleeve, and the more the number of times of reuse can be reduced by suppressing the damage of the sleeve accordingly. In order to reduce the gap at the connecting point of the polyethylene sleeve, it is required to make the draft as small as possible. Therefore, the draft of the polyethylene sleeve is 0.5 / 100 to 2/10.
It is preferably set to 0, and under such a condition, the number of reusable times can be guaranteed to about 15 to 20 times.

When the sleeve is taken out, the compressive stress δ acting on the sleeve cross section is proportional to (extraction force / sleeve cross section area). Therefore, since the extracting force is proportional to the product of the through hole length L and the sleeve outer peripheral length, and the sleeve cross-sectional area is proportional to the product of the sleeve outer peripheral length and the sleeve wall thickness t, the compressive stress δ is eventually L. Since δ must be maintained at a constant allowable stress in proportion to / t, the larger the through hole length L, the thicker the wall thickness t needs to be.

A conventional method can be used for the steps up to (a) in FIG. 2 above. However, in order to easily fix the sleeve, it is possible to remove the sleeve after removing the mold.
At least one end of the sleeve is removably fixed to the inner surface of the mold (it is difficult to pull out the sleeve by a method of tightly binding the rebar with a wire or the like). A feature of the method of forming a through hole according to the present invention is that a polyethylene sleeve provided with a predetermined draft is used for the sleeve, the polyethylene sleeve is extracted after curing and curing of concrete, and the extracted sleeve is recovered, and then It is to be reused in the construction of. In the conventional method, the sleeve is left inserted and the space inside the sleeve is used as a through hole. However, in the present invention, since the through hole is formed by removing the insert, the reason why the insert is sleeve-shaped, that is, hollow is based on a reason different from the conventional method. The reason is that (1) a sleeve with a draft can be stored and transported in a stack state due to the taper on the outer surface, and can be efficiently stored and transported for reuse because of its light weight. ,
(2) As will be described later, by attaching a core member to the mold and inserting the sleeve end into this core member, the sleeve can be stably fixed without being fixed to the reinforcing bar, and therefore the sleeve can be easily removed. And (3) the telescope type can be used to easily adjust the length. As described above, in the present invention, the use of the polyethylene taper with the outer surface is advantageous over the case of using the solid insert, and the stress acting on the sleeve due to the pulling force is large because it is not a solid substance. Nevertheless, due to the weak adhesion of polyethylene and the reduction of the pulling force due to the draft, the reduction in strength of the sleeve can be well suppressed and the sleeve can be reused 15 to 20 times.

FIGS. 3A to 3D show an embodiment in which a through hole is formed in a beam portion of a concrete wall.
In (a) to (d) of FIG. 3, 3 is a reinforcing bar assembled from main reinforcing bars and beam reinforcing bars, and 2a to 2c are molds, and after arranging, three-sided molds are assembled. Reference numeral 1 denotes a telescope type expandable / contractible double-tube polyethylene sleeve, which is shown in (a) (cross section) and (b) (side view) of FIG. And a male sleeve 1b fitted with a pedestal 11b at one end can be used. In FIG. 3A, 11a and 11b are the pedestals of the sleeve pieces 1a and 1b described above, and these pedestals 11a and 11b are nailed to the predetermined positions of the two-sided molds 2a and 2b at the positions where the through holes are to be formed. Fix it. At this time, the sleeve piece 1a (1b) still remains on the pedestal 11a (11b).
Is not fitted and the restriction of the swinging space of the hammer is reduced accordingly, so that the nailing and fixing can be easily performed. In FIG. 3A, the pedestal 11
After fixing the nails a and 11b, the telescoping type polyethylene sleeve 1 is shortened and arranged at a predetermined position from the gap of the bar arrangement 3, and then the telescopic type polyethylene sleeve 1 is extended. , One end of each sleeve piece 1a, 1b is fitted to each pedestal 11a, 11b (see FIG. 5).

The work from the nailing and fixing work of each pedestal to each mold to the fitting work of the telescope type sleeve to both pedestals can be performed by inserting a hand into the through hole formation planned position during the mold assembly. The three-way formwork 2a
Complete the assembly of ~ 2c. After that, as shown in (b) of FIG.
Wait for the curing and curing of the form 2 as shown in FIG.
a to 2c are removed, then a knock pin is inserted from the female sleeve piece 1a side to peel off the male sleeve piece 1b, and a knock pin is inserted from the hole after the peeling removal to peel off the female sleeve piece 1a. Then, as shown in FIG. 3D, the formation of the through hole h in the beam portion is completed.

The polyethylene sleeve 1 thus extracted is collected and reused for the next construction.

In the above single sleeve or telescope type sleeve, as shown in FIG. 6, the sleeve 1a (1
The stopper 100 is screwed or integrally provided on the large-diameter end side of b), the contact rod e is inserted into the sleeve, the tip of the contact rod e is applied to the stopper 100, and the contact rod e is pushed in. The sleeve can also be removed.

In the telescope type double tube polyethylene sleeve, the drafts of both sleeve pieces 1a and 1b are usually equal, the inner diameters of the sleeve pieces 1b and 1b are uniform, and the male side sleeve piece 1b. The maximum outer diameter at one end is equal to the inner diameter of the female sleeve piece 1a. in this case,
There is a gap in the male sleeve piece insertion opening at the tip of the female sleeve piece, but even under the maximum draft of 2/100, the gap can be made sufficiently small (eg, sleeve piece length 190 mm (550 mm), long 280 mm (9
(00 mm) through-hole, a draft of 2/10
The gap under 0 is 1.8 mm (7 mm).
If the gap is too large, it can be sealed by winding a plastic film or filling with putty].

In the telescope type double tube sleeve, the contact area of the male side sleeve piece 1b with concrete is smaller than the contact area of the female side sleeve piece 1a with concrete, and therefore the extraction force is small. It is also possible to make the draft of the male-side sleeve piece 1b smaller than the draft of the female-side sleeve piece 1a, or to reduce the wall thickness.

In the sleeve according to the present invention, even though the material cost is high, the sleeve is recycled many times as described above.
Since it is possible to significantly reduce the cost of the sleeve, it is possible to use a sleeve core provided with a silicone release layer, a release layer such as a fluorine resin coating, or the like.

FIGS. 7A to 7C show another embodiment in which a through hole is formed in a beam portion of a concrete wall. In (a) to (c) of FIG. 7, 3 is a reinforcing bar, 2a to
2c is a formwork. Reference numeral 1 denotes a telescope type expandable / contractible double polyethylene sleeve, which is composed of a female sleeve 1a and a male sleeve 1b with a pedestal removed, as shown in FIG. 8, in contrast to the double pipe sleeve shown in FIG. Things can be used. In (a) and (b) of FIG. 7, 1
11a, 111b Formwork 2 on both sides of the through hole formation planned position
It is a core member attached to a predetermined position of a and 2b, for example, a styrene foam core, and can be fixed with a double-sided adhesive tape. In FIG. 7A, each core member 111a
After the (111b) is fixed to the mold 2a (2b), the telescoping type polyethylene sleeve 1 is shortened and placed at a predetermined position from the gap of the bar arrangement, and then the telescoping type polyethylene sleeve. 1 is extended to connect one end of each sleeve piece 1a (1b) to each core member 111a (111
b) Insert on top. Further, it is also possible to fasten between one end of each sleeve piece 1a (1b) and each core member 111a (111b) with a bolt or a pin. The work from the fixing work of each core member to each formwork to the anchoring work of the telescope type sleeve to both pedestals can be performed during the period when the hand can be inserted into the through hole formation planned position during the formwork assembly. After this, the assembly of the three-way formwork is completed. After that, as shown in (b) of FIG. 7, concrete 4 is cast, waiting for curing and hardening of the concrete 4, and as shown in (c) of FIG. 7, the molds 2a to 2c are removed. For removal of the mold 2a (2b), the core member 111 made of expanded polystyrene is used.
Since a (111b) is easily torn by the retaining bolts and pins, the molds 2a and 2b can be removed smoothly. After removing the mold, in FIG. 7C, the knock pin is inserted from the female sleeve piece 1a side to peel off the male sleeve piece 1b, and the knock pin is inserted from the hole after the peeling removal to insert the female sleeve. The piece 1a is peeled off and removed, thereby completing the formation of the through hole in the beam portion.

The extracted polyethylene sleeve is collected and reused for the next construction.

Also in the embodiment shown in FIG. 7, the inner diameter of the female sleeve piece of the telescope type double polyethylene sleeve is made uniform, and the outer surface of the male sleeve piece is made into a taper surface of equal slope, and the male sleeve piece is The maximum outer diameter at one end is made equal to the inner diameter of the female sleeve piece. Also in this case, the gap formed at the tip of the female sleeve piece can be sealed by winding the film or filling the putty.

9A to 9D show an embodiment in which a through hole is formed in the floor slab. FIG. 9A
In (d), 2a is a form and 3 is a reinforcing bar arranged on the form. Reference numeral 1 denotes a polyethylene sleeve having a tapered outer surface provided with a predetermined draft, which is shown in FIG.
(A), the through hole is to be formed at the planned position, and the sleeve lower end 11 is fixed to the upper surface of the mold 2a with a nail.
For this polyethylene sleeve 1, the sleeve 1 having one end fitted to the pedestal 11 shown in (a) (cross-sectional view) and (b) (bottom view) of FIG. 10 can be used, and in (a) of FIG. Form 2a with pedestal 11 detached from sleeve 1
Then, fix the lower end of the sleeve 1 to the pedestal 1
1 can be fitted. Reference numeral 112 is a plug member fitted to the upper end of the polyethylene sleeve 1, and, for example, styrene foam can be used. After arranging the polyethylene sleeve 1 at a predetermined position in this way, concrete 4 is placed as shown in FIG. 9B, and the mold 2a is placed on the pedestal 11 after waiting for curing and hardening of the concrete 4. Together with the removal as shown in FIG. 9C, then the upper end of the polyethylene sleeve 1 is hit with a mallet to remove the sleeve as shown in FIG. 9D, whereby the through hole h is formed. To finish.

The polyethylene sleeve that has been removed is collected and reused for the next construction.

Also in the polyethylene sleeve described above,
As shown in FIG. 11, the stopper 1 is attached to one end of the sleeve 1.
00 is provided integrally or by screwing, the contact rod e is inserted, and the sleeve 1 can be removed by pushing in this contact rod. Further, in order to adjust the height of the polyethylene sleeve according to the required floor slab thickness, as shown in FIG. 12, an auxiliary sleeve piece 1c is screwed to the upper end of the sleeve main end 1 and screwed together. It can also be expanded and contracted by adjusting the allowance.

Even when the through holes are formed in the floor slab, after reinforcing bars are laid on the formwork, as shown in FIG.
A core member 111, for example, a styrofoam core is fixed to the upper surface portion of the mold 2a at a position where the through hole is to be formed by a double-sided adhesive tape 113, and the lower end of the polyethylene sleeve 1 is inserted onto the core member 111, and A bolt or a pin 1114 may be used to retain the core member 111.

In the present invention, the extracted polyethylene sleeve, including the pedestal, is collected and reused at the time of the next concrete wall or beam or floor slab construction. As long as the recovered polyethylene sleeve possesses the strength to withstand the extraction force, it can be reused, and if it cannot be reused as a sleeve, it can be disposed of by incineration or used as a recycled raw material.

The polyethylene sleeve used in the present invention can be manufactured by a blower molding method or an injection molding method, and the pedestal can be manufactured by an injection molding method. In this case, it is preferable to use the recycled raw material mixed with the virgin raw material.

As described above, the draft of the sleeve used in the present invention is preferably 0.5 / 100 to 2/100. The sleeve size is set according to the diameter of the through hole and the wall thickness. For example, in the telescope type double tube sleeve for the beam through hole, the through hole diameter is 75 φm.
m, 100φmm, 125φmm, 150φmm, 17
Applicable beam width 2 for 5 mm and 200 mm
20 mm to 280 mm, 300 mm to 400 mm, 40
24 types of 0 mm to 600 mm and 600 mm to 900 mm can be handled. (A) Applicable beam width 220 mm to
Although the sleeve length is 280 mm, the length is 190 m
m (b) Applicable beam width 300 mm to 400 mm, but sleeve length is 260 mm (c) applicable beam width 400
mm-600mm, but sleeve length is 3
The sleeve piece length for 70 mm (d) applicable beam width 600 mm to 900 mm can be 550 mm.

In the method of forming a through hole at the time of pouring concrete according to the present invention, since the sleeve is used as a mold material for forming the through hole, even if the sleeve is flammable polyethylene, the fireproof partition wall / slab It is possible to meet the conditions of (1), and under such circumstances, (1) the number of times the polyethylene sleeve can be reused is sufficiently large, so that the sleeve cost can be substantially reduced, and (2) cutting for size adjustment. There is no need for machining or attachment of attachment ear to the cut end,
The work cost can be reduced by shortening the work time. These points can also be confirmed from the following examples.

[0040]

EXAMPLE 1 Example 1 is the formation of the through holes shown in FIGS.
Using the telescope type double tube sleeve shown in Fig. 4, the length of each sleeve piece 1a, 1b (including the pedestal thickness) is 40c.
m, the draft of each sleeve piece 1a, 1b was 3/450, and the beam width was 70 cm. The pedestal 11a (11b) was fixed to the mold 2a (2b) by three-point nailing. The period from injection of concrete to removal of the form was 15 days.

[Embodiment 2] In contrast to Embodiment 1, instead of nailing the pedestal to the mold, as shown in FIGS. 7A to 7C, a styrofoam cylinder core 111a (111b) is adhered on both sides. Example 1 was the same as Example 1, except that the sleeve was fixed to the frame 2a (2b), one end of each sleeve was inserted into each styrofoam cylindrical core, and the outer circumference of one end of each sleeve was tightly bound with a plastic string.

[Third Embodiment] In contrast to the first embodiment, instead of nailing the pedestal to the mold, as shown in FIGS. 7A to 7C, a styrofoam cylindrical core is formed into a mold with a double-sided adhesive tape. Example 1 was the same as Example 1 except that one end of each sleeve was inserted on the styrofoam columnar core, and one end of each sleeve was fastened with a set bolt.

[Example 4] The same as Example 1 except that the draft of each sleeve piece was increased to 5/450.

[Embodiment 5] Compared with Embodiment 1, the draft of each sleeve piece is increased to 5/450, and instead of nailing the pedestal to the form, instead of (a) to (c) in FIG. ), The styrofoam columnar core was fixed to the mold by a double-sided adhesive tape, one end of each sleeve was inserted on the styrofoam columnar core, and one end of each sleeve was tightly bound with a plastic string. Same as

In the above-mentioned Examples 1 to 5, a common space in the temporary formwork having a beam width of 70 cm and a depth of 65 cm (with reinforcing bars)
Was carried out using. Twenty pieces of the temporary formwork 1 to 20 are prepared, and the sleeve used in the previous temporary formwork is reused in the next temporary formwork to sequentially arrange the first temporary formwork to the 20th temporary formwork. When the above-mentioned Examples 1 to 5 were repeated 20 times under the reuse of the sleeve, the sleeve was still in a reusable state even at the 20th time. Also,
The shortening of the working time due to the cutting process and the need to attach the fixing ear to the cutting end has been fully evaluated.

[Embodiment 6] Formation of through-holes during floor slab construction shown in (a) to (d) of FIG. 9, in which the sleeve 1 shown in FIG. The thickness (including the thickness of the pedestal 11) was 30 cm, the draft of the sleeve was 5/450, and the slab thickness was 25 cm. The pedestal was fixed to the formwork by three-point nailing. The period from injection of concrete to removal of the form was 15 days.

[Embodiment 7] In contrast to Embodiment 6, instead of nailing the pedestal to the mold, a polystyrene foam core is fixed to the mold with double-sided adhesive tape, and the lower end of the sleeve is inserted on the polystyrene foam core. The same as Example 6 except that the outer circumference of the lower end of the sleeve was bound with a wire.

[Embodiment 8] Compared to Embodiment 6, the draft of the polyethylene sleeve is reduced to 3/450, and instead of nailing the pedestal to the mold, a polystyrene foam cylindrical core is formed into a mold with double-sided adhesive tape. Example 6 was the same as Example 6 except that the lower end of the sleeve was fixed, the lower end of the sleeve was inserted onto the styrofoam columnar core, and the outer periphery of the lower end of the sleeve was tightly bound with a plastic string.

[Embodiment 9] Compared to Embodiment 6, the draft of the polyethylene sleeve is reduced to 3/450, and instead of nailing the pedestal to the form, as shown in FIG. 13, a styrofoam cylinder core 111 is used. Was fixed to the mold 2a with the double-sided adhesive tape 113, the lower end of the sleeve was inserted into the styrofoam cylindrical core, and the lower end of the sleeve 1 and the core 111 were fixed with the nail 114.

Comparative Example The same as Example 6 except that the sleeve draft was set to 0.

In Examples 6 to 9 and Comparative Example, a frame having a depth of 25 cm was placed on the upper surface of the frame, and a temporary frame which was arranged on the frame was used. Twenty pieces of the temporary formwork 1 to 20 are prepared, and the sleeve used in the previous temporary formwork is reused in the next temporary formwork to sequentially arrange the first temporary formwork to the 20th temporary formwork. As a result of repeating the above-described Examples 6 to 9 and Comparative Example, the sleeves in Examples 6 to 9 were still in a reusable state even after the 20th time. However, in the comparative example, the reuse became impossible at a relatively early time (the twelfth time). In addition, the reduction of the working time due to the cutting process and the need to fix the attachment ear to the cutting end was sufficiently evaluated in both the examples and the comparative examples.

[0052]

According to the sleeve for forming a through hole at the time of pouring concrete according to the present invention, the sleeve is arranged at the time of pouring a concrete wall, a beam or a floor slab, and after pouring concrete and removing the formwork. Even if the sleeve is flammable, it is possible to construct a fireproof partition wall / slab with a through hole and the taper of the outer surface with a draft is applied to make it difficult to adhere. Due to the weak adhesion and draft, the sleeve can be pulled out with a sufficiently small pulling force, the damage of the sleeve during the sleeve pulling out can be well suppressed and the sleeve can be reused many times, and the substantial material cost of the sleeve. Can be reduced.
Particularly, in the sleeve according to claim 5, since the wall thickness of the large diameter end of the sleeve, which is the fixed end of the formwork, is large, in the case of wall construction, the bending moment acting on the sleeve due to the weight of the concrete causes the formwork to move. Even if it becomes the maximum at the fixed end,
Deformation at the fixed end of the sleeve on the mold side can be well suppressed, the fixed state can be stably maintained, and the flattening of the sleeve can be favorably prevented. According to the method of forming a through hole at the time of pouring concrete according to claim 6, a fireproof partition wall with a through hole can be smoothly formed while reducing the substantial material cost of the sleeve by repeatedly using the sleeve. The slab can be constructed, and in particular, according to claim 4, since the sleeve length can be adjusted according to the wall thickness by expansion and contraction without cutting, the working time can be shortened, and particularly, according to claim 7, If
One core member is fixed to each formwork, and the sleeve can be fixed simply by inserting each sleeve into each core member.Therefore, compared to the conventional example in which multiple mounting ears are attached to the sleeve end You can save time. Therefore, according to the present invention,
Due to the synergistic effect of reducing the material cost of the sleeve and the working cost by shortening the working time, the cost can be dramatically reduced. Further, according to claim 8, the sleeve is fixed by inserting the sleeve end into the core member, and the flattening of the sleeve end against the weight of the poured concrete can be prevented more effectively by the core, and can be fixed stably.
It is advantageous for preventing the sleeve from being crushed.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a through hole forming sleeve according to the present invention.

FIG. 2 is a view showing a method of forming a through hole using the through hole forming sleeve according to the present invention.

FIG. 3 is a view showing an example of a method of forming a through hole according to claim 6;

FIG. 4 is a drawing showing a telescopic polyethylene sleeve used in the embodiment of FIG.

FIG. 5 is a view showing an example of a fixing structure of the telescopic polyethylene sleeve shown in FIG.

FIG. 6 is a view showing another example of the fixing structure of the telescopic polyethylene sleeve shown in FIG.

FIG. 7 is a view showing an example of a method of forming a through hole according to claim 7;

8 is a drawing showing a telescopic polyethylene sleeve used in the embodiment of FIG. 7. FIG.

FIG. 9 is a view showing an example of a method of forming a through hole of a floor slab according to the present invention.

10 is a drawing showing an example of a polyethylene sleeve used in the embodiment of FIG.

11 is a drawing showing another example of the polyethylene sleeve used in the embodiment of FIG. 9. FIG.

12 is a drawing showing another example of the polyethylene sleeve used in the embodiment of FIG. 9. FIG.

13 is a drawing showing an example of a polyethylene sleeve fixing structure used in the embodiment of FIG. 9. FIG.

FIG. 14 is a drawing showing a conventional example.

[Explanation of symbols]

1 Polyethylene sleeve 1a One sleeve piece 1b of telescopic sleeve 1b One sleeve piece of telescopic sleeve 2a Formwork 2b Formwork 2c Formwork 3 Reinforcing bar 4 Concrete 5 Mallet h Through hole

Claims (8)

[Claims] 1. A sleeve used to insert a concrete wall, a beam, or a floor when placing concrete, remove the formwork, and then remove the formwork to form a through hole.
A sleeve for forming a through hole at the time of placing concrete, characterized in that the outer surface is hard to adhere to the concunole and the outer surface is tapered with a draft. 2. A sleeve for forming a through hole during pouring of concrete according to claim 1, which is made of synthetic resin. 3. The sleeve for forming a through hole at the time of pouring concrete according to claim 1 or 2, which is made of polyethylene. 4. The sleeve for forming a through hole at the time of pouring concrete according to claim 1, wherein a release layer is provided on the surface of the sleeve core. 5. The sleeve for forming a through hole at the time of pouring concrete according to any one of claims 1 to 4, wherein the sleeve wall thickness is increased toward the large diameter end side. 6. A method of forming a through hole when a concrete wall, a beam or a floor is constructed, wherein at least one end of the through hole forming sleeve according to any one of claims 1 to 5 is fixed to the inner surface of the mold and then concrete is formed. A method for forming a through hole during concrete pouring, characterized in that the sleeve is removed after the mold is placed and the mold is removed, and the removed sleeve is reused during the next construction. 7. The method for forming a through hole in concrete pouring according to claim 6, wherein the sleeve is telescopically expandable. 8. The method of forming a through hole during concrete pouring according to claim 6 or 7, wherein a core member is attached to the inner surface of the form, and at least one end of the through hole forming sleeve is inserted into the core member.