Void sleeve

Abstract

To provide a void sleeve which can reduce a waste compared to a conventional void sleeve, and is excellent in workability when being removed after establishment of a partition structure made of concrete.SOLUTION: A void sleeve (1) used for forming a through hole (8H) in a partition structure (8) made of concrete (C) includes a sleeve body (2) which is made of a resin, and has a cylindrical peripheral wall part (20), and a bottom plate part (25) extending inward from the lower end of the peripheral wall part (20). A through hole (26) is formed in the bottom plate part (25).SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a void sleeve.

Background Art

[0002] In order to form a through-hole in a concrete partition structure that forms the framework of a building, a void sleeve is used. With a cylindrical void sleeve arranged, concrete is placed around the void sleeve, and after the concrete hardens, a concrete partition structure having a through-hole is constructed.

[0003] As such a void sleeve, for example, one made of a paper material such as kraft paper (paper void sleeve) as disclosed in Japanese Patent Application Laid-Open No. 2021-134550 (Patent Document 1) is preferably used.

[0004] For example, in order to ensure the fire resistance of a building, it is necessary to remove the combustible paper void sleeve after constructing the concrete partition structure. However, the paper void sleeve that has been used and removed once has to be discarded, and the increase in waste is not preferable from the viewpoint of environmental protection. In addition, the paper void sleeve has poor peelability from the hardened concrete, and the removal work requires time and effort.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] It is desired to realize a void sleeve that can reduce waste compared to the prior art and has excellent workability when removing after constructing a concrete partition structure.

Means for Solving the Problem

[0007] The void sleeve according to the present invention is a void sleeve used for forming a through hole in a concrete partition structure, made of resin, and includes a sleeve body having a cylindrical peripheral wall portion and a bottom plate portion extending inward from a lower end portion of the peripheral wall portion. A through hole is formed in the bottom plate portion.

[0008] According to this configuration, by forming the void sleeve with resin, it can be reused after being used and removed once. Therefore, compared with the case of using a paper void sleeve as conventionally used, waste can be reduced. Further, since a through hole is formed in the bottom plate portion of the sleeve body, when removing after constructing a concrete partition structure, the tip of a removal tool can be easily inserted from the through hole of the bottom plate portion to the lower surface side of the bottom plate portion. Therefore, the workability during removal can be improved.

[0009] Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiment examples described below.

[0010] As one aspect, it is preferable that a vertical gap is formed on the lower surface side at the inner end portion of the bottom plate portion having the through hole.

[0011] According to this configuration, since there is a vertical gap on the lower surface side at the inner end portion of the bottom plate portion, the tip of a removal tool can be inserted more easily on the lower surface side of the bottom plate portion. Therefore, the workability during removal can be further improved.

[0012] As one aspect, it is preferable that the sleeve body is composed of a plurality of divided bodies divided in the circumferential direction.

[0013] According to this configuration, since the plurality of divided bodies constituting the sleeve body can be stacked in a state of being separated from each other, the volume per void sleeve during transportation can be reduced. Therefore, the number of void sleeves that can be transported simultaneously can be increased, and the work efficiency related to the preparation for placing concrete and the removal after construction can be improved. Further, since it is originally a divided body, it is easier to peel off compared to a sleeve body having an integral structure, and the workability during removal can be further improved.

[0014] As one aspect, it is preferable that the plurality of divided bodies are connected by press-fitting a connecting portion provided on one side and a connected portion provided on the other side.

[0015] According to this configuration, the state in which the plurality of divided bodies are connected to each other can be favorably maintained by press-fitting the connecting portion and the connected portion. Therefore, for example, the entire void sleeve can be fixed only by fixing at least one of the plurality of divided bodies to the concrete formwork, and the workability during the preparation for placing concrete can be improved. Further, since there are also few fixing portions to be removed after construction, the workability during removal after construction can also be improved.

[0016] As one aspect, it is preferable that protruding support portions that protrude in the circumferential direction from one side and support the other from the radially inner side are provided at opposing portions in the circumferential direction of the plurality of divided bodies.

[0017] According to this configuration, it is possible to prevent a radial displacement from occurring at opposing portions in the circumferential direction of the plurality of divided bodies due to the external pressure after the concrete is placed. Therefore, while the sleeve body is composed of a plurality of divided bodies, the through hole formed in the partition structure can be finished to have a substantially constant inner diameter.

[0018] As one aspect, the circumferential contact portions of the plurality of divided bodies are provided on the bottom plate portion, In the contact portion, it is preferable that a circumferential gap is formed between the peripheral wall portions of the plurality of divided bodies in a state where the plurality of divided bodies are in contact with each other.

[0019] According to this configuration, when removing the concrete partition structure after construction, it becomes difficult for the circumferential end portions of the peripheral wall portions of the plurality of divided bodies to interfere with each other, and it becomes easier to move the plurality of divided bodies. Therefore, the workability at the time of removal after construction can be improved. By simply bringing the plurality of divided bodies into contact with each other in the circumferential direction at the contact portion, a circumferential gap of an appropriate size can be formed, and the effect related to the improvement of workability at the time of removal can be obtained regardless of the skill of the operator.

[0020] As one aspect, It is preferable to further include a deflection prevention member that engages with the upper edge of the peripheral wall portion over the entire circumference to prevent the deflection deformation of the peripheral wall portion inward in the radial direction when external pressure by concrete acts.

[0021] According to this configuration, it is possible to prevent the peripheral wall portion from deflecting and deforming inward in the radial direction due to the external pressure after the concrete is placed. Therefore, the through-hole formed in the partition structure can be finished to have a substantially constant inner diameter.

[0022] As one aspect, It is preferable that the deflection prevention member has an engagement guide portion that guides the engagement of the deflection prevention member with the upper edge of the peripheral wall portion.

[0023] According to this configuration, even if the deflection prevention member is slightly displaced with respect to the peripheral wall portion, the deflection prevention member can be easily engaged with the upper edge of the peripheral wall portion by the guidance of the engagement guide portion.

[0024] This specification also discloses a construction method for forming a through-hole in a concrete partition structure.

[0025] Such a construction method is A construction method for forming a through-hole in a concrete partition structure, A void sleeve made of resin and having a cylindrical peripheral wall portion and a bottom plate portion extending inward from the lower end portion of the peripheral wall portion is provided in a formwork, and a step of installing the void sleeve in which a through hole is formed in the bottom plate portion; A step of pouring concrete into the formwork in which the void sleeve is installed; After the construction of the partition structure, a step of inserting the tip of a removal tool into the through hole of the bottom plate portion and removing the void sleeve from the formwork; including.

[0026] According to this configuration, by making the void sleeve used when forming a through hole in a concrete partition structure made of resin, it can be reused after being used and removed once. Therefore, waste can be reduced compared to the case of using a paper void sleeve as used conventionally. Further, since a through hole is formed in the bottom plate portion of the sleeve body, in the step of removing the void sleeve from the formwork, the tip of the removal tool can be easily inserted from the through hole of the bottom plate portion to the lower surface side of the bottom plate portion. Therefore, the workability when removing and removing the void sleeve can be improved.

[0027] Further features and advantages of the present invention will become more apparent from the following illustrative and non-limiting description of embodiments described with reference to the drawings.

Brief Description of the Drawings

[0028]

Figure 1

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Figure 8

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Figure 12

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Figure 14

Figure 15

Figure 16

Mode for Carrying Out the Invention

[0029] Embodiments of the void sleeve will be described with reference to the drawings. The void sleeve 1 of the present embodiment is used to form a through hole 8H in a partition structure 8 made of concrete C. Examples of the partition structure 8 made of concrete C include concrete floor slabs such as reinforced concrete (RC) structures and steel-reinforced concrete (SRC) structures as shown in FIG. 1, for example.

[0030] To construct the partition structure 8 made of concrete C, a plurality of reinforcing bars 92 are installed in a three-dimensional lattice pattern in a formwork 91 (only the bottom plate is shown in FIG. 1), and the void sleeve 1 is installed at a position that does not interfere with the reinforcing bars 92, and then concrete C is poured into the formwork 91. When the concrete C hardens, a partition structure 8 made of concrete C with a through hole 8H (see FIGS. 10 etc.) formed at the position where the void sleeve 1 is installed is constructed.

[0031] In addition, in the present embodiment, the concrete C means a mixture of cement, water, and aggregate. As the aggregate, only fine aggregate with a small particle size (for example, sand) may be used, or in addition to the fine aggregate, coarse aggregate with a larger particle size than that (for example, gravel) may be included. That is, the concrete C in the present embodiment is a concept including both a mixture of cement, water, fine aggregate, and coarse aggregate (so-called concrete in a narrow sense) and a mixture of cement, water, and fine aggregate (so-called mortar).

[0032] As shown in FIGS. 1 and 2, the void sleeve 1 of the present embodiment includes a sleeve main body 2, a lid body 4, and a spacer 6. The sleeve main body 2, the lid body 4, and the spacer 6 are configured as separate bodies independent of each other. The sleeve main body 2 and the lid body 4 are each one as a whole, while the spacer 6 is shown as only one in FIGS. 1 and 2, but may be two or more. In addition, the sleeve main body 2 is always used when constructing the partition structure 8 made of the concrete C, while the lid body 4 and the spacer 6 may or may not be used depending on the construction site. Furthermore, the number of the spacers 6 used may also vary.

[0033] The void sleeve that has been widely used conventionally is a paper void sleeve made of a paper material such as kraft paper, whereas the void sleeve 1 of the present embodiment is a resin void sleeve made of a resin material. The resin type constituting the void sleeve 1 is not particularly limited, and for example, general-purpose resins such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) can be used.

[0034] The void sleeve 1 preferably can withstand an environmental temperature of, for example, -40°C to 90°C. By having a cold resistance temperature of -40°C, it can be used without problems even in cold regions in winter. By having a heat resistance temperature of 90°C, it can be used without problems even when the concrete C generates heat during hardening. The range of the environmental temperature that the void sleeve 1 can withstand is more preferably -30°C to 80°C, and even more preferably -20°C to 70°C.

[0035] As shown in FIGS. 2 to 4, the sleeve body 2 has a cylindrical peripheral wall portion 20 and a bottom plate portion 25 extending inward from the lower end portion of the peripheral wall portion 20. The peripheral wall portion 20 is formed in a cylindrical shape as a whole. The bottom plate portion 25 is formed in an annular shape (doughnut shape) as a whole.

[0036] In this embodiment, the sleeve body 2 having the peripheral wall portion 20 and the bottom plate portion 25 is composed of a plurality of divided bodies 2A divided in the circumferential direction. More specifically, the sleeve body 2 is composed of a set of two divided bodies 2A that are halved (divided into two) into the same shape. These pair of divided bodies 2A are configured to be separable, and in the combined state, they form a cylindrical peripheral wall portion 20 as a whole and an annular bottom plate portion 25 as a whole. The pair of divided bodies 2A respectively have a part of the peripheral wall portion 20 forming a semi-cylindrical shape and a part of the bottom plate portion 25 forming a semi-annular shape.

[0037] In the following description, the part of the peripheral wall portion 20 (semi-cylindrical portion) of the divided body 2A in the separated state is also referred to as the "peripheral wall portion 20". Similarly, the part of the bottom plate portion 25 (semi-annular portion) of the divided body 2A in the separated state is also referred to as the "bottom plate portion 25". That is, in this embodiment where the sleeve body 2 is composed of a pair of divided bodies 2A, the "peripheral wall portion 20" and the "bottom plate portion 25" are used as concepts including both the overall structure and the partial structure.

[0038] The pair of divided bodies 2A have opposing end portions 21 at both circumferential ends of the semi-cylindrical peripheral wall portion 20. The opposing end portions 21 face each other in the circumferential direction when the pair of divided bodies 2A are combined. The opposing end portions 21 are formed on flat surfaces along the radial direction. In this embodiment, the opposing end portions 21 correspond to the "opposing portions". In this embodiment, when the pair of divided bodies 2A are combined, the opposing end portions 21 of the respective divided bodies 2A abut against each other in the circumferential direction. Therefore, in this embodiment, the outer surface of the peripheral wall portion 20 becomes a cylindrical surface without irregularities.

[0039] In addition, in the present embodiment, the pair of divided bodies 2A has a protruding support portion 22 at one end in the circumferential direction of the semi-cylindrical peripheral wall portion 20. The protruding support portion 22 is formed so as to protrude in the circumferential direction from the lower end portion side (bottom plate portion 25 side) of the semi-cylindrical peripheral wall portion 20. The protruding support portion 22 is formed in a region occupying approximately one-third of the lower end portion side of the peripheral wall portion 20. The protruding support portion 22 is formed in a U-shaped cross-section having a pair of upper and lower support plates 22A and a connecting plate 22B connecting them. The support plate 22A is provided in a state orthogonal to the inner surface side of the peripheral wall portion 20. The connecting plate 22B connects the pair of support plates 22A vertically.

[0040] In a state where the pair of divided bodies 2A are combined, the protruding support portion 22 supports the peripheral wall portion 20 (here, particularly the opposing end portion 21) of the other divided body 2A from the radially inner side. By each protruding support portion 22 of the pair of divided bodies 2A supporting the peripheral wall portion 20 of the other divided body 2A from the radially inner side, the peripheral wall portion 20 is kept in a cylindrical shape as a whole.

[0041] Reinforcing ribs 23 are integrally formed at the boundary portion between the peripheral wall portion 20 and the bottom plate portion 25 where they are integrated. The reinforcing ribs 23 are formed in a flat plate shape having a certain thickness. Also, in the present embodiment, the reinforcing ribs 23 are formed in a right triangle shape having a side portion along the inner surface of the peripheral wall portion 20, a side portion along the upper surface of the bottom plate portion 25, and a hypotenuse connecting them. A plurality (three in this example) of reinforcing ribs 23 are provided per one divided body 2A. The plurality of reinforcing ribs 23 are arranged parallel to each other.

[0042] A through-hole 26 is formed in the central portion of the bottom plate portion 25. The through-hole 26 is formed in a circular shape as a whole. In the present embodiment, the through-hole 26 is formed so as to have concavities and convexities in the radial direction in a plan view and to form a circular shape as a whole. By having such a through-hole 26, the bottom plate portion 25 is formed in an annular shape (doughnut shape). At the radially inner end of the semi-annular bottom plate portion 25, fixing holes 29 through which a fixture F (see FIG. 10 etc.) for fixing the sleeve body 2 to the bottom plate of the mold 91 can be inserted are formed. A plurality of fixing holes 29 are provided in the circumferential direction, and the plurality of fixing holes 29 are distributed at predetermined intervals (which may be constant or not) in the circumferential direction. In the present embodiment, two fixing holes 29 are formed between a pair of adjacent reinforcing ribs 23.

[0043] Also, at both circumferential ends of the semi-annular bottom plate portion 25 in the pair of divided bodies 2A, a connecting portion 27 and a connected portion 28 are provided separately. The connecting portion 27 is provided at one circumferential end of the bottom plate portion 25, and the connected portion 28 is provided at the other end. The connecting portion 27 is formed in a rectangular shape in a plan view and protrudes in the circumferential direction. The connected portion 28 is formed with a notch in the circumferential direction in a shape complementary to the connecting portion 27.

[0044] As shown in FIG. 4, one connecting portion 27 of the pair of divided bodies 2A engages with the connected portion 28 of the other of the pair of divided bodies 2A, and the other connecting portion 27 of the pair of divided bodies 2A engages with the connected portion 28 of one of the pair of divided bodies 2A, so that the pair of divided bodies 2A are in a combined state.

[0045] Here, in the present embodiment, although the connected portion 28 has a shape complementary to the connecting portion 27, its size is formed slightly smaller than that of the connecting portion 27. For this reason, the engagement between the connecting portion 27 and the connected portion 28 is made in a state where a slight repulsive force is generated. As a result, the pair of divided bodies 2A are connected by press-fitting the connecting portion 27 provided on one side and the connected portion 28 provided on the other side.

[0046] When, as in this embodiment, a pair of split bodies 2A are connected by press-fitting a connecting portion 27 provided on one side and a connected portion 28 provided on the other side, the state in which the pair of split bodies 2A are connected can be maintained by this press-fitting. For this reason, the amount of the fixture F used for fixing the sleeve body 2 to the bottom plate of the formwork 91 can be reduced, and the workability can be improved. That is, while fixing only one of the pair of split bodies 2A with the fixture F, the other connected by press-fitting can also be position-held on the bottom plate of the formwork 91, and materials and labor can be reduced.

[0047] As shown in FIG. 5, in this embodiment, the thickness of the bottom plate portion 25 is not uniform, and the thickness of the bottom plate portion 25 at a specific circumferential position is thinner at its inner end (the end on the through-hole 26 side). More specifically, the thickness around a plurality of fixing holes 29 formed dispersedly in the circumferential direction at the inner end of the bottom plate portion 25 is thinner. In this embodiment, since the thickness around the plurality of fixing holes 29 provided at the inner end of the bottom plate portion 25 is thinner, a vertical gap Gv is formed on the lower surface side at the inner end of the bottom plate portion 25 having the through-hole 26. In this embodiment, the vertical gap Gv is formed between the bottom plate portion 25 and the bottom plate of the formwork 91.

[0048] The vertical gap Gv of this embodiment is formed in a region where the reinforcing ribs 23 are provided in the circumferential direction. The vertical gap Gv is formed in an arc-shaped band in plan view so as to extend over a plurality (three in this example) of reinforcing ribs 23. As will be described later, this vertical gap Gv serves as a space for easily inserting the tip of the removal tool B when removing the void sleeve 1 after constructing the concrete C-made partition structure 8 (see FIG. 12).

[0049] As shown in FIGS. 2 and 5, etc., the lid body 4 is formed to cover the upper opening of the sleeve body 2. As shown in FIGS. 6 and 7, the lid body 4 is mainly composed of a disc-shaped top plate 41. A central hole 42 is formed through the center of the top plate 41. Further, a hanging wall 43 that hangs downward toward the lower side (the sleeve body 2 side) is formed at the peripheral edge of the top plate 41. A locking groove 44 that is recessed upward is formed over the entire circumference on the lower surface of the hanging wall 43. The groove width of the locking groove 44 is approximately the same as the thickness of the peripheral wall portion 20 of the sleeve body 2 and the radial thickness of the locking projection 63 of the spacer 6 described later.

[0050] An annular rib 46 and an intersecting rib 47 are formed on the top plate 41 of the present embodiment. The annular rib 46 is formed to have a slightly smaller diameter than the hanging wall 43, and is provided so as to protrude downward from the lower surface of the top plate 41 inside the radial direction of the hanging wall 43. The vertical length of the annular rib 46 is longer than the vertical length of the hanging wall 43.

[0051] The intersecting rib 47 is formed integrally with the annular rib 46 in a state of intersecting (orthogonal in this example) with the annular rib 46. A plurality (12 in this example) of intersecting ribs 47 are provided in the circumferential direction, and these plurality of intersecting ribs 47 are dispersedly arranged at regular intervals in the circumferential direction. The intersecting rib 47 of the present embodiment is formed in a triangular shape, more specifically an isosceles triangular shape, when viewed in the circumferential direction (viewed along the extending direction of the annular rib 46). In the present embodiment, the radially outer side portion of the triangular intersecting rib 47 is an outward inclined side 47a that extends obliquely. The outward inclined side 47a is inclined so as to gradually move radially outward as it goes upward.

[0052] When the void sleeve 1 is used without the spacer 6, the lid body 4 is attached to the sleeve body 2 in such a form that the locking groove 44 is locked to the upper end edge 20u of the peripheral wall portion 20 from above. At the time of this attachment, even if the centers of the lid body 4 and the peripheral wall portion 20 are misaligned, when the outward inclined side 47a of the intersecting rib 47 abuts against the upper end edge 20u of the peripheral wall portion 20, the misalignment is corrected and the locking groove 44 is appropriately locked to the upper end edge 20u of the peripheral wall portion 20.

[0053] Further, when the void sleeve 1 is used with the spacer 6, the lid body 4 is attached to the spacer 6 in such a manner that the locking groove 44 locks onto the locking projection 63 of the spacer 6 from above. Even when the centers of the lid body 4, the peripheral wall portion 20, and the spacer 6 are misaligned during this attachment, when the outer inclined side 47a of the cross rib 47 abuts against the locking projection 63 of the spacer 6, the misalignment is corrected and the locking groove 44 appropriately locks onto the locking projection 63.

[0054] Whether the lid body 4 is directly attached to the sleeve body 2 or indirectly attached via the spacer 6, since the upper opening of the sleeve body 2 is covered by the lid body 4, it is possible to prevent the concrete C from flowing into the inside of the sleeve body 2. Although a central hole 42 is formed in the lid body 4, it is advisable to block it by pasting a curing tape or the like during the placement of the concrete C (see FIG. 1).

[0055] As shown in FIGS. 2 and 5, when used, the spacer 6 is inserted between the sleeve body 2 and the lid body 4. Depending on the specifications of the construction site, the thickness of the partition structure 8 may vary at a predetermined pitch. As an example, the thickness of the partition structure 8 can be set at a 10 mm pitch within the range of 200 mm to 280 mm. By making the thickness of the spacer 6 equal to the pitch width (10 mm in the above example), the number of spacers 6 inserted between the sleeve body 2 and the lid body 4 can be adjusted to appropriately correspond to the specifications for each construction site. Note that the combined thickness of the sleeve body 2 and the lid body 4 is set to be equal to the minimum thickness of the partition structure 8 (200 mm in the above example).

[0056] As shown in FIGS. 8 and 9, the spacer 6 is mainly composed of an annular (ring-shaped) annular body 61. On the upper surface of the annular body 61, locking protrusions 63 protruding upward are formed over the entire circumference. The radial thickness of the locking protrusion 63 is equal to the thickness of the peripheral wall portion 20 of the sleeve body 2. Further, on the lower surface of the annular body 61, locking grooves 64 recessed upward are formed over the entire circumference. The groove width of the locking groove 64 is approximately the same as the thickness of the peripheral wall portion 20 of the sleeve body 2. Furthermore, inwardly inclined walls 65 extending obliquely radially inward from the lower end portion of the annular body 61 are formed over the entire circumference. The outer surface 65a of the inwardly inclined wall 65 is inclined so as to gradually move radially outward as it goes upward. Also, an inward flange 66 extends radially inward from the lower end portion of the inwardly inclined wall 65.

[0057] The spacer 6 is attached to the sleeve body 2 in such a manner that the locking groove 64 locks onto the upper end edge 20u of the peripheral wall portion 20 from above, and the lid body 4 is attached to the locking protrusion 63 in such a manner that the locking groove 44 of the lid body 4 locks onto the locking protrusion 63 from above. When attaching the spacer 6 to the sleeve body 2, even if the centers of the spacer 6 and the peripheral wall portion 20 are misaligned, when the outer surface 65a of the inwardly inclined wall 65 abuts against the upper end edge 20u of the peripheral wall portion 20, the misalignment is corrected and the locking groove 64 appropriately locks onto the upper end edge 20u of the peripheral wall portion 20.

[0058] Both the lid body 4 and the spacer 6 can engage with the upper end edge 20u of the peripheral wall portion 20 of the sleeve body 2 over the entire circumference depending on the presence or absence of the spacer 6. By engaging the lid body 4 or the spacer 6 with the upper end edge 20u of the peripheral wall portion 20 over the entire circumference, deflection deformation of the peripheral wall portion 20 radially inward is prevented. In particular, even when an external pressure due to the concrete C acts on the sleeve body 2 from the outside after pouring the concrete C into the formwork 91, deflection deformation of the peripheral wall portion 20 radially inward can be prevented. In the present embodiment, in combination with the protruding support portions 22 provided on the pair of divided bodies 2A constituting the sleeve body 2 supporting the peripheral wall portion 20 of the other divided body 2A from radially inside, deflection deformation of the peripheral wall portion 20 radially inward can be effectively prevented.

[0059] In this embodiment, depending on the usage mode of the void sleeve 1, either the lid body 4 or the spacer 6 constitutes the "flexure prevention member P". When the void sleeve 1 is used without the spacer 6, the lid body 4 that engages with the upper end edge 20u of the peripheral wall portion 20 over the entire circumference functions as the flexure prevention member P (see FIG. 10). In this case, the outer inclined side 47a of the cross rib 47 provided on the lid body 4 functions as an engagement guiding portion E that guides the engagement of the lid body 4 as the flexure prevention member P with the upper end edge 20u of the peripheral wall portion 20.

[0060] Further, when the void sleeve 1 is used with the spacer 6, the lowermost spacer 6 that engages with the upper end edge 20u of the peripheral wall portion 20 over the entire circumference functions as the flexure prevention member P (see FIGS. 1 and 13, etc.). In this case, the outer surface 65a of the inward inclined wall 65 of the spacer 6 functions as an engagement guiding portion E that guides the engagement of the spacer 6 as the flexure prevention member P with the upper end edge 20u of the peripheral wall portion 20.

[0061] Hereinafter, the work for removing the void sleeve 1 after constructing the partition structure 8 made of concrete C will be described step by step.

[0062] First, the removal work when the void sleeve 1 is used without the spacer 6 (when the lid body 4 is directly attached to the sleeve body 2) will be described.

[0063] First, the curing tape attached to the upper surface of the lid body 4 is peeled off to expose the central hole 42. Then, as shown in FIG. 10, the tip of the removal tool B such as a burr is inserted into the internal space of the void sleeve 1 from the exposed central hole 42. Then, the tip of the removal tool B is hooked on the lower surface side of the lid body 4 and pulled upward to remove the lid body 4 from the sleeve body 2.

[0064] Note that since a cylindrical rib is formed around the central hole 42 in the lid body 4 so as to protrude downward, the resin lid body 4 is not easily damaged when pulled by the removal tool B.

[0065] Next, as shown in FIG. 11, the tip of the removal tool B is inserted from above between the inner surface of the through hole 8H of the partition structure 8 and the outer surface of the peripheral wall portion 20 of the sleeve body 2, and the inner surface of the through hole 8H and the outer surface of the peripheral wall portion 20 are peeled off.

[0066] When the peeling operation is completed over the entire circumference, next, as shown in FIG. 12, the sleeve body 2 is removed from the bottom plate of the formwork 91. At this time, the tip of the removal tool B is inserted into the through hole 26 of the bottom plate portion 25, and further, the tip is inserted into the vertical gap Gv formed on the lower surface side around the plurality of fixing holes 29 in the bottom plate portion 25. Then, using the removal tool B as a lever, while removing the fixture F, the entire sleeve body 2 can be easily removed from the formwork 91.

[0067] When the thickness of the partition structure 8 is thicker than the standard according to the specifications of the construction site, as shown in FIG. 13, the difference can be absorbed by interposing one or more spacers 6. In the illustrated example, three spacers 6 are interposed between the sleeve body 2 and the lid body 4.

[0068] Regarding the removal work in the case where such a void sleeve 1 is used with spacers 6 (when the lid body 4 is indirectly attached to the sleeve body 2 via the spacers 6), the removal of the first lid body 4 is the same as above (see FIG. 10). After removing the lid body 4, as shown in FIG. 14, the tip of the removal tool B is hooked on the lower surface of the inward flange 66 of the uppermost spacer 6 and pulled upward to remove the spacer 6. This is repeated until all the spacers 6 are removed. Regarding the subsequent removal of the sleeve body 2, it is the same as above.

[0069] Thus, the void sleeve 1 of this embodiment can be easily removed from the formwork 91 after constructing the compartment structure 8 made of concrete C. Further, the void sleeve 1 is made of resin and can be repeatedly reused even after being used once and removed. Therefore, the amount of waste can be reduced, which is environmentally friendly.

[0070] Since the sleeve body 2 is composed of a pair of divided bodies 2A that are divided in the circumferential direction, these can be separated and overlapped. By carrying them in this state at the construction site, the number of void sleeves 1 that can be transported simultaneously can be increased, improving the transportation efficiency and thus the overall work efficiency. Also, by storing them in this state, the storage space can be kept small and the storage cost can be reduced.

[0071] 〔Other Embodiments〕 (1) In the above embodiment, the configuration in which the vertical gap Gv is formed between the bottom plate portion 25 and the bottom plate of the formwork 91 has been described as an example. However, without being limited to such a configuration, the vertical gap Gv may be formed as a radial recess inside the bottom plate portion 25.

[0072] (2) In the above embodiment, the configuration in which one vertical gap Gv in an arc-shaped band in plan view is formed for each divided body 2A has been described as an example. However, without being limited to such a configuration, a plurality of vertical gaps Gv may be intermittently formed in the circumferential direction for each divided body 2A. In this case, for example, vertical gaps Gv may be formed around the fixing holes 29 at the inner end of the bottom plate portion 25.

[0073] (3) In the above embodiment, the configuration in which the vertical gap Gv is formed at the inner end of the bottom plate portion 25 has been described as an example. However, without being limited to such a configuration, the vertical gap Gv does not necessarily have to be formed.

[0074] (4) In the above-described embodiment, an example in which the sleeve main body 2 is composed of a pair of divided bodies 2A that are divided in the circumferential direction has been described. However, without being limited to such a configuration, for example, the sleeve main body 2 may be composed of three or more divided bodies 2A that are divided in the circumferential direction. Alternatively, the sleeve main body 2 may not have a divided structure and may be integrally formed as a whole.

[0075] (5) In the above-described embodiment, a configuration in which the protruding support portion 22 is formed in a U-shaped cross section having a pair of upper and lower support plates 22A and a connecting plate 22B connecting them has been described as an example. However, without being limited to such a configuration, the specific shape of the protruding support portion 22 may be arbitrary as long as it can support the peripheral wall portion 20 of another divided body 2A from the radially inner side. For example, as shown in FIG. 15, the protruding support portion 22 may have ribs 22C inside thereof. The ribs 22C are formed in a plate shape extending in the radial direction and the circumferential direction so as to connect the peripheral wall portion 20 and the connecting plate 22B. In the illustrated example, three ribs 22C are formed at predetermined intervals in the vertical direction, but the number, position, shape, etc. thereof may be appropriately changed. Further, the protruding support portion 22 may be formed, for example, solidly or in a comb shape. Alternatively, the protruding support portion 22 may not necessarily be provided.

[0076] (6) In the above-described embodiment, a configuration in which a pair of divided bodies 2A are connected by press-fitting a connecting portion 27 provided on one side and a connected portion 28 provided on the other side has been described as an example. However, without being limited to such a configuration, a pair of divided bodies 2A may be connected by merely engaging a connecting portion 27 provided on one side and a connected portion 28 provided on the other side. Further, the connecting portion 27 may have a shaft portion protruding in the circumferential direction and a swelling portion formed on the tip side thereof, etc., so that the connecting portion 27 and the connected portion 28 may be connected in a non-removable state.

[0077] (7) In the above-described embodiment, as an example, the configuration in which the opposing end portions 21 of the respective divided bodies 2A abut against each other in the circumferential direction in a state where the pair of divided bodies 2A are joined together has been described. However, without being limited to such a configuration, in a state where the pair of divided bodies 2A are joined together, the opposing end portions 21 of the respective divided bodies 2A may be spaced apart from each other in the circumferential direction. For example, as shown in FIG. 16, in a state where the pair of divided bodies 2A are joined together by contact in the circumferential direction at the connecting portion 27 and the connected portion 28, a circumferential gap Gc may be formed between the opposing end portions 21. The circumferential gap Gc may have a size (for example, a circumferential width of 1 mm to 5 mm) that can avoid the initial interference between the opposing end portions 21 of the pair of divided bodies 2A when operating with the removal tool B at the time of withdrawal after construction. In such a configuration, the connecting portion 27 and the connected portion 28 that are in contact in the circumferential direction correspond to the "contact portion", and the circumferential gap Gc corresponds to the "circumferential gap".

[0078] (8) In the above-described embodiment, as an example, the void sleeve 1 includes the sleeve body 2, the lid body 4, and, if necessary, the spacer 6, and a configuration in which either the lid body 4 or the spacer 6 functions as the anti-flexure member P has been described. However, without being limited to such a configuration, for example, the void sleeve 1 may be composed of the sleeve body 2 and a dedicated anti-flexure member P. As the dedicated anti-flexure member P, for example, a ring-shaped member having a shape similar to that of the spacer 6 (a shape in which the locking protrusion 63 does not exist) can be used. In this case, when placing the concrete C, it is preferable to cover the upper opening of the sleeve body 2 with a wrapping material, a sheet material, or the like so that the concrete C does not flow into the sleeve body 2.

[0079] (9) In the above-described embodiment, as an example, the engagement of the lid body 4 with the upper end edge 20u of the peripheral wall portion 20 is guided by the outer inclined side 47a of the cross rib 47. Also, as an example, the engagement of the spacer 6 with the upper end edge 20u of the peripheral wall portion 20 is guided by the outer surface 65a of the inward inclined wall 65. However, without being limited to such a configuration, the specific means for guiding the engagement of the lid body 4 and the spacer 6 with the upper end edge 20u of the peripheral wall portion 20 may be appropriately changed.

[0080] (10) In the above-described embodiment, the configuration in which the deflection prevention member P has the engagement guide portion E (in the lid body 4, the outer inclined side 47a of the cross rib 47 / in the spacer 6, the outer surface 65a of the inward inclined wall 65) has been described as an example. However, without being limited to such a configuration, the deflection prevention member P may not have the engagement guide portion E.

[0081] (11) The configurations disclosed in the above-described embodiments (including the above-described embodiment and other embodiments; the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs. Regarding other configurations as well, all the embodiments disclosed in this specification are illustrative in all respects, and can be appropriately modified within the scope not departing from the gist of the present disclosure.

Explanation of Reference Numerals

[0082] 1 Void sleeve 2 Sleeve body 2A Divided body 4 Lid body 6 Spacer 8 Partition structure 8H Through hole 20 Peripheral wall portion 20u Upper edge 21 Opposite end portion (opposite part) 22 Protrusion support portion 25 Bottom plate portion 26 Through hole 27 Connecting portion (contact portion) 28 Connected portion (contact portion) 47 Cross rib 47a Outer inclined side 65 Inward inclined wall 65a Outer surface P Deflection prevention member E Engagement guide portion Gv Vertical gap (gap in the vertical direction) Gc Circumferential gap (gap in the circumferential direction) C Concrete

Claims

1. A void sleeve used for forming a through hole in a concrete partition structure, which is made of resin, comprises a sleeve body having a cylindrical peripheral wall portion and a bottom plate portion extending inward from the lower end portion of the peripheral wall portion, and the void sleeve has a through hole formed in the bottom plate portion.

2. The void sleeve according to claim 1, wherein a vertical gap is formed on the lower surface side at the inner end portion of the bottom plate portion having the through hole.

3. The void sleeve according to claim 1 or 2, wherein the sleeve body is composed of a plurality of divided bodies divided in the circumferential direction.

4. The void sleeve according to claim 3, wherein the plurality of divided bodies are connected by press-fitting a connecting portion provided on one side and a connected portion provided on the other side.

5. The void sleeve according to claim 3, wherein protruding support portions that protrude in the circumferential direction from one side and support the other side from the radially inner side are provided at circumferentially opposing portions of the plurality of divided bodies.

6. The bottom plate portion has circumferentially abutting portions of the plurality of divided bodies, and a circumferential gap is formed between the peripheral wall portions of the plurality of divided bodies in a state where the plurality of divided bodies abut against each other at the abutting portion. The void sleeve according to claim 3.

7. The void sleeve according to claim 1 or 2, further comprising a deflection prevention member that engages with the upper edge of the peripheral wall portion over the entire circumference to prevent the deflection deformation of the peripheral wall portion inward in the radial direction when an external pressure by concrete acts.

8. The void sleeve according to claim 7, wherein the deflection prevention member has an engagement guiding portion that guides the engagement of the peripheral wall portion with the upper edge.

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