JPH0241614B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a method for constructing a concrete slab. More specifically, the present invention relates to a method for constructing a hollow concrete slab in which an embedding material such as a synthetic resin foam is embedded to make the slab hollow.

<Background and conventional technology> In recent years, construction of medium-to-high-rise buildings such as apartment complexes, general buildings, and warehouses has been carried out by forming concrete slabs by pouring on site. It is widely practiced to make slabs hollow in order to expand the indoor space and ensure long spans by removing them. In order to make the slab hollow, a factory-produced PC board is used as the lower layer, which is combined with a hollow cylinder of iron plate as an embedding material and a box-shaped lightweight solid material, and the upper layer of concrete is poured on-site to create a hollow slab. While this construction method has the advantage of eliminating the need for on-site construction of the lower layer, it also requires the transportation of heavy PC boards to the construction site, and the need for truck cranes,
It is also necessary to unload the cargo at the site using a large lifting capacity such as a crawler crane, and depending on the road conditions near the site or the site conditions around the building, it may be necessary to In some cases, it was impossible to carry out the construction method because it could not be brought onto the site.

In order to prevent the embedded material from moving during concrete pouring, for example, if the embedded material is made of lightweight solid material, a holding member such as a long bar or strip should be placed on top of the embedded material so that both ends of the embedded material are The holding member is placed so that it protrudes from the embedding material, and the part of the holding member that protrudes from the embedding material is connected to the lower reinforcing bars or PC board with wires, etc., and the work of fixing the embedding material is also troublesome and inefficient. It was something.

<Purpose> The present invention has been made in view of the above problems, and it is an object of the present invention to provide a concrete slab construction method that facilitates construction and improves efficiency.

<Structure> The structure of the present invention to achieve the above object is that after the following steps (1), (2), and (3) are sequentially performed, concrete is poured, and the following fixing members, supports, and spindles are installed. It is characterized by surrounding it with concrete together with the embedded material.

(1) The process of arranging the fixing member for connecting the support shaft on the demolding temporary formwork for concrete pouring. (2) The process of removing the support for holding the embedded material by straddling the above fixing member. Process of placing on the temporary formwork (3) The supporting shaft is inserted into the embedded material, the embedded material is placed on the support, and the supporting shaft and the fixing member are connected and fixed. A process of fixing the embedding material in a floating state above the demolding temporary formwork so that the material is in a state where the material is removed (Embodiment) Next, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The embodiments shown in FIGS. 1 to 9 are made of synthetic resin foam such as expanded polystyrene as the embedding material,
The case is shown in which a rectangular polygonal prism having horizontal planes X and X' on the top and bottom, vertical planes Y and Y' on the sides, and a slope part Z between the horizontal planes X and X' and the vertical planes Y and Y' is used. There is.

First, on the wooden demolding temporary formwork panel 1 for concrete pouring that has been laid, the support 3 and the support shaft are placed corresponding to the ends of the embedded material 5, the middle part, and the boundary between the embedded materials. The fixing member 2 for 4 is set upright (see Fig. 1).

This fixing member 2 consists of a support ring 21 that is brought into contact with the temporary formwork 1 for demolding, and a double-threaded bolt 22 that is screwed to the middle of the inner diameter of this support ring 21 and raised up.
The entire structure is fixed by fixing the support ring 21 from the back side of the demolding temporary formwork 1 with bolts 23, washers 24, nuts 25, etc. (Figs. 2 and 5). reference).

Incidentally, the insertion holes 11 for the bolts 23 are formed in the demolding temporary formwork 1 prior to the above. Further, as the fixing member 2, one in which the support ring 21 and the bolt 22 are integrally formed is also preferable.

Next, in order to support and hold the embedded material 5 in a state floating on the temporary demolding form 1, a support 3 is arranged on the temporary demolding form 1 so as to straddle the fixing member 2, Insert the flanged member 26 having an internal diameter screw into the through hole 31 on the upper surface of the support 3, screw the insertion side into the upper part of both threaded bolts 22, and move the support 3 relative to the demolding temporary formwork 1. (See Figure 2).

The above-mentioned support 3 has legs 33 formed on a receiving plate 32 that can extend along a part of the lower surface of the embedded material 5. It is desirable that the tips of the legs 33 be subjected to anti-corrosion treatment for the purpose of preventing stains from forming on the directly finished ceiling due to rust on the concrete slab A after dismantling the demolding temporary formwork 1. . As a specific example of this anti-corrosion treatment, there are cases where the tips of the legs 33 are covered with synthetic resin caps 33', or where the tips are directly plated (see FIG. 2). The support 3 has four legs 3 at the connection points between the embedded materials 5 and 5.
3 pieces are required, and 2 pieces may be used in other parts.
(See Figure 3).

Then, the support shaft 4 having threaded portions 41 at both ends is screwed into the flanged member 26 inserted into the support 3 to fix it upright on the support 3 (see FIG. 3).

In addition, for the above-mentioned assembly structure for supporting the embedded material during construction, the fixing member 2, the support 3, the flanged member 26, the double-threaded bolt 22, and the support shaft 4 are assembled in advance and integrated. It is also preferable to do so.

In this state, the implant 5 is placed on the support 3 while inserting the support shaft 4 into the support shaft insertion portions 51 on both end faces of the implant 5 and the intermediate portion. Then, a presser plate 6 having a stabbing blade-like locking part 61 is inserted into the support shaft 4 and tightened with a nut 62 to fix the implant 5 (see FIGS. 6 to 9). Note that it is also possible to use a presser plate 6 that does not have the locking portion 61.

Next, concrete 7 is poured around the embedding material 5 which is held floating on the demolding temporary formwork 1 by the support 3 and fixed by the support shaft 4 and the holding plate 6 as described above. By surrounding the material 5, the support 3, etc. with concrete, and dismantling the demolding temporary formwork 1 after the poured concrete 7 has hardened, a concrete slab A with a hollow part formed by the embedded material 5 is formed. (See Figure 6).

Although the explanation has been omitted, the above-mentioned slab construction is carried out while arranging necessary reinforcement at the appropriate time. For example, the lower end main reinforcement 81 and the lower end distribution reinforcement 8
1', before installing the fixing member 2 for the support 3,
In terms of workability, it is preferable to arrange the intermediate connecting reinforcements 82, which together with the main reinforcements constitute the beam-shaped reinforcements, before the support shaft 4 is erected and fixed. Of course, the upper end main reinforcement 83 and the upper end distribution reinforcement 83' are arranged before concrete placement.

When using the above-described buried polygonal columnar embedded material 5, the side surfaces of the embedded material 5 form vertical planes Y and Y' parallel to the vertical portion 82' of the intermediate connecting bar 82.
Compared to the case of burying a hollow cylinder made of iron plates, it is possible to increase the spacing between the embedded materials 5 without significantly reducing the non-concrete portion in the concrete slab A, and it is easier to assemble the intermediate connecting bars 82. It is also possible to install the intermediate connecting bar 82 having a stable shape before setting the embedded material 5, making it easier to set the intermediate connecting bar 82 in a stable state.
Also, when setting the embedded material 5 between the intermediate connecting bars 82 after the fact, the embedded material 5 is made of lightweight synthetic resin foam and its upper and lower surfaces are horizontal distribution bars 83', 81. It is easy to handle and set because of its stable shape with horizontal planes X and X' parallel to ', and since the embedded material 5 has an inclined surface Z between its side and top and bottom surfaces,
The intermediate part C between the embedded material 5 and the embedded material 5 can be configured with a vertically inclined widened part d, and the intermediate parts C form a continuous arch structure, which can enhance the slab strength and provide excellent performance. It becomes something that can be demonstrated.

In addition, by arranging the support shaft 4 at the boundary between the embedded materials 5 and 5 as shown in the figure, it is possible to share the support 3, the holding plate 6, etc. of the adjacent embedded materials 5, and the number of them used can be reduced. This makes it even more cost-effective. Of course, the support shafts 4 are not used at the boundary between the embedding materials 5, 5, but are inserted directly into the embedding material 5 with an appropriate length interval in the length direction of the embedding material 5. You may.

On the other hand, in the above construction, the embedded material 5 is
The mutual construction order of the process of placing the support shaft 4 on top and the process of standing and fixing the support shaft 4 may be performed in any order,
Contrary to the case described above, if the step of placing the embedding material 5 is performed first, insert the support shaft 4 into the support shaft insertion part 51 of the embedding material 5, and then turn the upper part with a spanner or the like. What is necessary is just to screw it into the flanged member 26.

Although the above embodiment is a construction method in which the support 3 is independently fixed to the demolding temporary formwork 1, it is also possible to omit the independent fixation of the support 3.

That is, as shown in FIGS. 7 to 9, the support shaft 4 with the fixing member 2' connected to the tip is inserted into the through hole 31 of the support 3 placed on the demolding temporary formwork 1. , After fixing this fixing member 2' to the demolding temporary formwork 1,
As in the embodiment described above, when the embedding material 5 is placed on the support 3 and the embedding material 5 is held down by the presser plate 6, the support 3 is also held down and fixed so that it does not move. This means that the effort of fixing the support 3 independently can be omitted. As shown in FIG. 7, the fixing member 2' is made by inserting a plurality of divided pieces 27a in the axial direction into the insertion holes 11 of the demolding temporary formwork 1 while elastically deforming them, and using the non-return claws 27b at the tips. As shown in Fig. 8, a screw nail 27c at the tip or a screw nail screwed into the demolding temporary formwork 1 can be considered, as shown in Fig. 8, or a formwork that is divided into multiple parts in the axial direction as shown in Fig. 9. It is also possible to prevent the divided pieces 27d from coming off by spreading them outward by the impact of the internal pin 27e. In this case, the support shaft 4 is
The fixing member 2' and the fixing member 2' are configured to be detachable by screwing together, and the fixing member 2' alone is arranged and fixed on the demolding temporary formwork 1 prior to the arrangement of the support 3. .

In the above embodiment as well, the step of fixing the support shaft 4 upright and the step of placing the embedded material 5 may of course be interchanged, and the support shaft 4 may be Fix it upright on the demolding temporary formwork 1,
A construction method in which the support 3 and the embedded material 5 are sequentially inserted can also be adopted.

Next, the embodiments shown in FIGS. 10 to 13 show cases where a box-shaped embedding material 5 is used. To explain in detail below, first, the support 3 is placed on the demolding temporary formwork 1 that has been laid down (see FIG. 10).

The support 3 consists of a tripod-like or bipod-like leg 33 on a receiving plate 32. In the case of a tripod-like structure, it is sufficient to simply place it on the demolding temporary formwork 1; In this case, temporarily secure the demolding temporary formwork 1 with nails or the like to prevent it from falling down. The receiving plate 32 is formed with a convex portion 34 for positioning the embedded material 5 and a through hole 31 through which the support shaft 4 is inserted.

Next, the embedding material 5 is placed on the support 3 placed on the demolding temporary formwork 1 as described above and held in a floating state (see FIG. 11). At this time, the embedding material 5
Positioning is performed by aligning a pre-formed concave portion 52 (FIG. 12) with the convex portion 34 of the support 3. In the case of the figure, the embedding material 5 is a hollow body 5 made of non-foamed synthetic resin formed hollow by blow molding.
0.0, 50' are used, butted against each other and combined into one body by fitting, but it is also possible to use a solid foam such as expanded polystyrene that is integrally molded from the beginning. Hollow body 50,5 as shown in the figure
0', the side wall of the hollow body, which is the abutting portion x, acts as a substantial reinforcing rib, so that sufficient pressure resistance can be ensured.

A recess 53 similar to the upper recess 52 is formed on the upper surface of the embedding material 5, and a recess 53 similar to the upper recess 52 is formed at the bottom of both recesses 52, 53. A hole 54 is formed. Further, the lower surface of the embedded material 5 is inclined toward the center, and is arranged along the receiving plate 32 of the support 3. Note that numerals 55 and 56 in the drawings indicate unevenness for fitting and integration.

Note that, in practice, it is possible to omit the concave portions 52, 53 and the convex portions 34, 63 that fit therewith.

Then, the support shaft 4 is inserted into the insertion hole 54 of the embedding material 5 held floating on the demolding temporary formwork 1 in this way, and is also inserted through the through hole 31 of the support tool 3 to provide support. A fixing member 2' having a sharp portion 27f, for example, made of plastic material or the like is connected to the tip of the shaft 4.
is fixed to the demolding temporary formwork 1 by driving or the like, and the embedding material 5 and the support 3 are pressed down with the presser plate 6 to fix the whole thing (see FIG. 12).

Next, concrete 7 is placed on the demolding temporary formwork 1, and after the poured concrete 7 has solidified, the demolding temporary formwork 1 is dismantled to form a concrete slab A in which a hollow part is formed by the embedding material 5. (See Figure 13).

In the above-mentioned embodiments, necessary reinforcements such as the lower end main reinforcement, the intermediate connecting reinforcement, and the upper end main reinforcement are provided at the appropriate time, but their explanation and illustration are omitted.

Further, as the fixing member 2' for fixing the support shaft 4, members similar to those shown in FIGS. 7 to 9 can be used. Furthermore, as shown in FIG. 14, the support shaft 4 is formed integrally with a widened part 42 corresponding to the fixing member 2', and a pin 43 is inserted into the inside of this support shaft 4 to extend the widened part 42 outward. The support shaft 4 can also be fixed in an upright position by expanding it.

Then, the process of fixing the support shaft 4 upright and the embedded material 5
In this embodiment as well, any of the steps for placing the support shaft 4 may be performed first, and after the support shaft 4 is erected and fixed, the support tool 3 and the embedding material 5 are sequentially inserted therein. In particular, in this case, the support 3 can be supported by the support shaft 4, so even if the support 3 has a double-legged leg 33, it cannot be nailed to the temporary formwork 1. This eliminates the need for temporary fixing, etc., making construction more efficient.

Furthermore, if the support 3 is integrally attached to the embedded material 5 in advance in a factory or the like, on-site construction can be carried out more efficiently than in the case of the above embodiment in which the support 3 is arranged individually. It's suitable as it gets older.

On the other hand, the foam embedding material 5 may be formed of a foam made from polyethylene, polypropylene, polyvinyl chloride, copolymers mainly composed of these, etc., in addition to the above-mentioned foamed polystyrene. Furthermore, the embedding material 5 may be made of water-resistant cardboard. Furthermore, when using an integral combination of hollow bodies made of non-foamed resin, the embedding material 5 may be composed of three hollow bodies 50, 50', 50'' as shown in FIG. In some cases, substantial reinforcing ribs can be formed in two locations, resulting in even stronger pressure resistance.Furthermore, as a hollow embedding material 5, as shown in FIG.
A plurality of 5 and 56 are formed in the vertical direction and the two are fitted together, or a hollow body 5 as shown in FIG.
0 and 50', which are integrated via a joint member 57 that can fit into the recesses 55 and 55, as well as hollow bodies 50 and 50' as shown in FIG. It is possible to use an embedded material 5 that is integrated by various means, such as forming a band-shaped joint part 58 that projects vertically on the abutting part side, and connecting the joint parts 58 with bolts at predetermined intervals. Can be done.

<Effect> As described above, according to the method for constructing a concrete slab according to the present invention, concrete is poured onto the temporary formwork that can be demolished on-site, etc., without using a PC board as the lower layer, and the concrete is hardened. Since a hollow concrete slab can be constructed by later dismantling the temporary formwork, there is no need to transport heavy PC boards to the construction site or unload the PC boards using large-scale truck cranes, etc. ,
As mentioned above, there is no design inconvenience in that construction methods using PC boards cannot be implemented depending on the surrounding conditions of the site, and it can be adapted to all locational conditions around the site. On the other hand, since the embedded material is fixed by inserting a spindle into the embedded material, the work of fixing the embedded material can be done very easily and efficiently, thus shortening the slab construction period. This brings about various excellent effects, such as the ability to reduce costs and reduce costs.

[Brief explanation of the drawing]

The figure shows an embodiment of the invention.
The figure is a perspective view showing the state in which the fixing member is installed.
The figure is a front view showing a state in which the support is fixed, Fig. 3 is a perspective view showing a state in which the support shaft is fixed in an upright position, Fig. 4 is a perspective view showing a state in which the embedded material is held floating, and Fig. 5 is a perspective view showing a state in which the mounting material is held floating.
The figure is a perspective view showing the fixing member, spindle, and presser plate before they are connected, Figure 6 is a sectional view of the completed concrete slab, and Figures 7 to 9 are front views showing examples of changes to the fixing member. , FIG. 10 is a perspective view showing a state in which the support in another embodiment is arranged;
Figure 11 is a perspective view showing the embedded material placed on the support, Figure 12 is a front view showing the embedded material prevented from lifting, and Figure 13 is a cross section of the completed concrete slab. 14 is a sectional view showing an example of a change in the support shaft, FIG. 15 is a front view showing an example of changing the embedding material, FIG. 16 is a perspective view showing another embedding material, and FIG. 17 is a sectional view showing an example of a change in the support shaft. Similarly, FIG. 18 is a front view, and FIG. 18 is a perspective view. 1...Temporary formwork for demolding, 2, 2'...Fixing member, 3
...Bearing tool, 4...Spindle, 5...Embedded material, 6...
Holding plate for embedded material, A...Concrete slab.

Claims (1)

[Scope of Claims] 1. After passing through the following steps (1), (2), and (3) in sequence, concrete is poured, and the following fixing members, supports, and support shafts are surrounded by concrete together with embedded materials. A concrete slab construction method characterized by: (1) The process of arranging the fixing member for connecting the support shaft on the demolding temporary formwork for concrete pouring. (2) The process of removing the support for holding the embedded material by straddling the above fixing member. Process of placing on the temporary formwork (3) The supporting shaft is inserted into the embedded material, the embedded material is placed on the support, and the supporting shaft and the fixing member are connected and fixed. Step 2 of fixing the embedding material in a floating state above the demolding temporary formwork so that the concrete slab according to claim 1 uses a synthetic resin foam as the embedding material. construction method. 3. The method for constructing a concrete slab according to claim 1, using an inverted polygonal column having sloped portions at the four corners as the embedding material. 4. The method for constructing a concrete slab according to claim 1, using an integral combination of a plurality of hollow bodies made of synthetic resin as the embedding material.