Spacer structure for visualizing covering depth and construction method

Abstract

To provide a lightweight and simple spacer structure and to improve the working efficiency of concrete skeleton construction.SOLUTION: This spacer structure 10 is used for visualizing the covering depth of a reinforcement before bar arrangement work in skeleton work. This bearing device is composed of a thin-walled cylindrical temporary sleeve 12 arranged around an actual sleeve 11 with a clearance P in the radial direction, and a plurality of support members 13 arranged in an annular space Q between the temporary sleeve 12 and the actual sleeve 11 at intervals in the circumferential direction. The temporary sleeve 12 is preferably made of paper, and the support member 13 is preferably made of a synthetic resin foam and formed into a prismatic shape.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spacer structure for visualizing the thickness of reinforcing bars prior to reinforcement work for floors, walls, beams, etc. in skeleton construction, and a construction method for a concrete skeleton using the same. [Background technology]

[0002] Patent Document 1 discloses a method for constructing a slab through hole, which includes the steps of installing a cylindrical body (actual sleeve) on top of a floor formwork, installing a space securing member having a thickness equal to or greater than a predetermined cover thickness and securing a space around the cylindrical body, arranging reinforcing bars around the space securing member, and removing the space securing member and pouring slab concrete. This method makes it possible to secure a predetermined cover thickness between the reinforcing bars arranged in the slab and the through hole formed in the slab.

[0003] Furthermore, it is disclosed that by utilizing a predetermined thickness, multiple space-retaining members can be stacked vertically to a predetermined height, thereby accommodating concrete slabs of different thicknesses, and that the space-retaining members can be made of an elastic material and have vertical grooves to facilitate attachment and detachment to the cylindrical body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7059486 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the construction method of Patent Document 1, a predetermined cover thickness can be ensured between the reinforcing bars placed in the slab and the through-holes formed in the slab. However, a space-retaining member with a thickness greater than the cover thickness is quite heavy, so the work of placing it around the solid sleeve and removing it is cumbersome and time-consuming. Furthermore, when constructing a space-retaining member by stacking hollow rings of a predetermined height, while the weight of each hollow ring is lighter, the stacking and removal work is cumbersome and even more time-consuming. Furthermore, at a typical construction site, many through-holes are formed per floor, resulting in a significant amount of work.

[0006] The technical objective of the present invention is to provide a spacer structure and a method for constructing a concrete structure that can reduce the weight of space-retaining members by combining members of specific shapes, thereby improving the work efficiency of construction of concrete structural bodies such as floor slabs, walls, and beams. [Means for solving the problem]

[0007] The spacer structure of the present invention is a spacer structure 10 for visualizing the thickness of reinforcing bars prior to reinforcement work in structural construction, and is characterized by comprising a thin-walled cylindrical temporary sleeve 12 arranged around an actual sleeve 11 with a radial gap P therebetween, and a plurality of support members 13 arranged circumferentially at intervals from each other within an annular space Q between the temporary sleeve 12 and the actual sleeve 11.

[0008] In such a spacer structure 10, the temporary sleeve 12 is preferably made of paper. Also, the support member 13 is preferably made of a synthetic resin foam, and further, the support member 13 is preferably in the shape of a rectangular pillar.

[0009] The method for constructing a concrete structure of the present invention is characterized by placing a spacer structure 10 consisting of the aforementioned temporary sleeve 12 and multiple support members 13 on the outside of the actual sleeve 11 (S3), carrying out reinforcement work (S4), removing the spacer structure 10 (S5), and then pouring concrete (S6).

[0010] In such a construction method, when installing the spacer structure 10, it is preferable to place a temporary sleeve 12 around the actual sleeve 11 (S1), and then insert multiple support members 13 into the annular space Q between the actual sleeve 11 and the temporary sleeve 12 (S2). [Effects of the Invention]

[0011] The spacer structure of the present invention is composed of a thin-walled cylindrical temporary sleeve and multiple support members, so both the weight of each member and the overall weight are lightweight. This makes it easy to store and transport the spacer structure members, reducing the burden on workers and improving construction efficiency. Furthermore, the space (cavity) between the temporary sleeve and the actual sleeve can be directly seen. This makes it easy to grasp the area of ​​the covering thickness.

[0012] In such a spacer structure, if the temporary sleeve is made of paper, it is possible to reduce the weight and cost. Also, temporary sleeves of the desired length can be easily manufactured by cutting a long cardboard tube to the specified length at the construction site.

[0013] Furthermore, if the support member is made of a synthetic resin foam, it is easy to obtain the member by repurposing a heat insulating material, etc. Furthermore, if the support member is shaped like a rectangular pillar, it can be obtained even more easily by cutting a heat insulating material, etc.

[0014] The concrete structure construction method of the present invention employs the above-mentioned spacer structure, which makes it easy to store and transport components, reduces the burden on workers, and improves construction efficiency. Furthermore, when installing the spacer structure, if a temporary sleeve is placed around the actual sleeve and multiple support members are then inserted into the annular space between the actual sleeve and the temporary sleeve, the temporary sleeve can be firmly fixed to the actual sleeve and can be easily removed. [Brief explanation of the drawings]

[0015] [Figure 1]1 is a partially cutaway perspective view showing an embodiment of a spacer structure of the present invention attached to a sleeve; [Figure 2] 2A and 2B are a plan view and a longitudinal cross-sectional view of the spacer structure shown attached to a solid sleeve. [Figure 3] FIG. 2 is an exploded perspective view of the actual sleeve and spacer structure. [Figure 4] 1 is a schematic process diagram showing one embodiment of a concrete structure construction method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The spacer structure 10 shown in Figure 1 is a structure used to visualize the thickness of the reinforcing bars before the reinforcing bar arrangement work for floor slabs in the construction of a reinforced concrete structure, and consists of a thin-walled cylindrical temporary sleeve 12 arranged around the actual sleeve 11 with a radial gap P therebetween, and a plurality of support members 13 arranged at intervals from each other in the annular space Q between the temporary sleeve 12 and the actual sleeve 11.

[0017] 2A, in this embodiment, three support members 13 are inserted between the actual sleeve 11 and the temporary sleeve 12, and the support members 13 are spaced at approximately equal intervals in the circumferential direction. This makes it easy to arrange the actual sleeve 11 and the temporary sleeve 12 concentrically. However, the number of support members 13 may be four or more.

[0018] The material of the temporary sleeve 12 is not particularly limited, but a material that is stable in shape, lightweight, and readily available is preferred, and paper, i.e., a paper tube, is particularly preferred. A paper tube is preferably a so-called void tube, which is made by spirally wrapping paper such as bonded kraft paper around an iron pipe or the like multiple times and drying and hardening it to form a relatively rigid tube. However, a shape-retaining synthetic resin pipe or the like can also be used. In the case of paper, a synthetic resin coating may be applied to the surface to impart resistance to moisture and humidity. This allows for repeated use, contributing to resource conservation and environmental protection.

[0019] Considering structural strength, it is preferable that the thickness of the temporary sleeve 12 increases as the outer diameter increases. For example, when the outer diameter is 200 mm, the thickness T is about 1.5 to 3 mm, when the outer diameter is 300 mm, the thickness T is about 2 to 4 mm, and when the outer diameter is 400 mm, the thickness T is about 3 to 5 mm, i.e., about 1 / 80 to 1 / 120 of the outer diameter.

[0020] The temporary sleeve 12 can be easily manufactured by cutting a commercially available long cardboard tube to the desired length at a construction site or the like. However, it may also be cut to a pre-designed length at a cardboard tube manufacturing factory or the like. The temporary sleeve 12 is made about 30 to 50 mm longer than the thickness of the concrete slab to be poured. It may be made about the same length as the actual sleeve 11, but making it about 20 to 40 mm longer than the actual sleeve 11 makes it easier to handle (see Figure 2B).

[0021] The support member 13 is made of a synthetic resin foam. Polystyrene foam (closed-cell foam), which is commonly used as a heat insulating material, is particularly preferred. An example of a commercially available polystyrene foam is Styrofoam (registered trademark) from DuPont-Styrofoam Corporation. Commercially available polystyrene foam is in the form of a plate. A plate of polystyrene foam approximately 25 to 35 mm thick is cut to a width of approximately 25 to 30 mm to form the support member 13, which is a prism with a rectangular cross section (see FIG. 2A). The length of the support member 13 is approximately 20 to 40 mm longer than the actual sleeve 11 to facilitate insertion between the actual sleeve 11 and the temporary sleeve 12 (see FIG. 2B). When the support member 13 is made of a synthetic resin foam, it is preferable to insert the support member 13, which has a thickness of approximately 25 to 35 mm, in a state compressed by approximately 15 to 25% during insertion. This allows the actual sleeve 11, temporary sleeve 12, and support member 13 to be integrated as a whole by the elastic restoring force of the support member 13, making it easier to handle.

[0022] The support member 13 can be a rectangular column, or a polygonal or cylindrical column, such as a column with a trapezoidal cross section. The upper and lower bases may be concave and convex to match the outer surface of the actual sleeve and the inner surface of the temporary sleeve. However, a rectangular column with a rectangular cross section is preferred, as it is easy to process and generates less waste material. The support member 13 can be prepared in a long, thin shape and cut to the required length at the construction site.

[0023] The actual sleeve 11 is a cylindrical formwork for forming a through hole when pouring concrete, and can be made of conventional materials such as steel pipes or synthetic resin pipes such as polyvinyl chloride. The actual sleeve 11 is placed on a steel deck plate (see reference numeral 14 in Figure 4) that forms the underside of the slab.

[0024] As shown in Fig. 3, the spacer structure 10 is composed of a temporary sleeve 12 and a plurality of support members 13, which are separate components until they are assembled. These are then attached to the periphery of the actual sleeve 11, forming a single unit as shown in Fig. 1. Then, in this state, reinforcement work is carried out to assemble the reinforcing bars 16 (see reinforcement work step S4 in Fig. 4).

[0025] Next, referring to FIG. 4, a construction method for a concrete frame using the spacer structure 10 will be described. Note that, although a construction method for a floor slab will be described as an embodiment, it can also be applied to walls and beams. First, as shown in the upper left of FIG. 4, actual sleeves 11 are placed on the deck plate 14 and fixed with L-shaped metal fittings 15 or the like. The positions of the actual sleeves 11 are the positions where through-holes in the floor slab will be formed, and are marked in advance. Depending on the size of the structural frame, the number of actual sleeves 11 is 30 to 100 per floor. The deck plate 14 inside the actual sleeves 11 has not yet been penetrated. Then, as shown by the imaginary lines, temporary sleeves 12 are placed around the actual sleeves 11 (temporary sleeve placement process S1). At this time, concentricity does not need to be given much consideration.

[0026] Next, a plurality of support members 13 are inserted in order between the temporary sleeve 12 and the actual sleeve 11 (support member insertion step S2). As a result, the temporary sleeve 12 is arranged concentrically with respect to the actual sleeve 11, and the spacer structure 10 is assembled. In other words, even if the temporary sleeve 12 and the actual sleeve 11 are not concentric, the temporary sleeve 12 is easily displaced when the support members 13 are inserted, and a concentric state is achieved (support member insertion state S3). Note that the thickness of the support members 13 may be made slightly thicker than the width of the gap P, and the support members 13 may be press-fit into the space Q while compressing them by about 15 to 25%. In this case, the temporary sleeve 12 can be firmly fixed.

[0027] In this support member inserted state S3, as shown in Figure 1, the annular space Q between the actual sleeve 11 and the temporary sleeve 12 can be directly seen. Therefore, the space that should be the cover thickness can be intuitively grasped. This annular space Q is the space into which the ready-mixed concrete is poured.

[0028] Next, as shown in the upper right of Figure 4, reinforcing bars 16 for the floor slab are laid (reinforcing bar laying process S4). At this time, the actual sleeve 11 is surrounded by the temporary sleeve 12 at a predetermined interval. Therefore, the reinforcing bar laying work is carried out while avoiding the space Q, and as a result, the covering thickness B is secured.

[0029] After the reinforcement work is completed, the temporary sleeve 12 is first removed. This causes the multiple support members 13 to disassemble all at once (spacer structure removal process S5). Therefore, the temporary sleeve 12 and support members 13 can be easily removed. For example, about 100 spacer structures 10 can be removed by one worker in about 15 minutes.

[0030] In this state, concrete 17 for the floor slab is poured (concrete pouring step S6). Since the concrete is poured up to near the upper end of the actual sleeve 11, it is preferable to cover the upper end opening of the actual sleeve 11 with a lid 18 before pouring the concrete. Since the concrete 17 flows up to the periphery of the actual sleeve 11, a floor slab 19 with a predetermined covering thickness B around the reinforcing bars 16 is obtained.

[0031] After the concrete is poured, the lid 18 is removed and the deck plate inside the actual sleeve 11 is removed by gas welding or other methods, leaving a floor slab 19 with a through hole. The removed spacer structure 10 is transported and stored for the next construction project, and temporary sleeves of corresponding diameters are used for each of the actual sleeves with various diameter standards. These temporary sleeves can be stored nested, which has the advantage of requiring less space for transportation and storage.

[0032] While the preferred embodiments of the spacer structure and concrete framework construction method of the present invention have been described above, the present invention is not limited to these and various modifications can be made within the scope of the invention. For example, while the actual sleeve is cylindrical in the above embodiment, it may be a pipe with an oval or oval cross section, in which case the temporary sleeve should also be adjusted to match that shape. Furthermore, while the above construction method embodiment has been described as a floor slab construction method, it can also be used in construction where sleeves are installed in walls (exterior walls, partition walls) and beams. [Explanation of symbols]

[0033] 10 Spacer structure 11 Real Sleeve 12 Temporary Sleeve 13 Support member P Gap Q Space T Temporary sleeve thickness 14 Deck Plate 15 L-shaped bracket 16 Reinforced concrete 17 Concrete 18 Lid 19 Floor slab S1 Temporary sleeve placement process S2 Support member insertion process S3 Support member inserted S4 Reinforcement construction process S5 Spacer structure removal process S6 Concrete pouring process B Coverage

Claims

1. A spacer structure for visualizing the thickness of reinforcing bars prior to reinforcement work in framework construction, a thin-walled cylindrical temporary sleeve disposed around the actual sleeve with a radial gap therebetween; a plurality of support members arranged at intervals in the circumferential direction in an annular space between the temporary sleeve and the actual sleeve; Spacer structure.

2. 2. The spacer structure of claim 1, wherein said temporary sleeve is made of paper.

3. 2. The spacer structure according to claim 1, wherein said support member is made of synthetic resin foam.

4. The spacer structure of claim 1 , wherein said support members are prismatic.

5. The spacer structure according to claim 1 is disposed on the outside of the main sleeve; A method of constructing a concrete frame in which reinforcement work is carried out, the spacer structure is removed, and then concrete is poured.

6. 6. A method for constructing a concrete structure according to claim 5, wherein when the spacer structure is attached, a temporary sleeve is placed around the actual sleeve, and then a plurality of support members are inserted into the annular space between the actual sleeve and the temporary sleeve.

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