JPH0241613B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> This invention relates to cast-in-place concrete slabs. More specifically, the present invention relates to a hollow concrete slab cast on-site in which an embedded material such as a synthetic resin foam is embedded to make the slab hollow.

<Background and conventional technology> In recent years, construction of mid-to-high-rise buildings such as apartment complexes, general buildings, and warehouses has been carried out by forming concrete slabs by pouring on-site. In order to expand indoor space through removal and ensure a long span, it is widely practiced to make slabs hollow. In addition to hollow cylinders made of iron plates as embedding materials, recently plate-shaped bodies made of synthetic resin foam have also been used.

However, in order to increase the ratio of non-concrete parts in the slab by using the iron plate as hollow cylinders, it is necessary to narrow the pitches at which the hollow cylinders are arranged. Therefore, when performing on-site construction using the above-mentioned hollow tube as an embedded material, first, after completing the assembling process of the lower end reinforcement, install equipment piping such as electricity, water supply and drainage, etc., then set the hollow tube, and then install it on top of the hollow tube. After assembling the upper end reinforcement, the upper and lower end reinforcements are crossed with the S-shaped stirrup forming the intermediate reinforcement in the narrow space of the hollow cylinder to complete the reinforcement arrangement and concrete is poured. The above-mentioned S-shaped stirrup can be stabilized after setting the hollow cylinder, but it is troublesome to install, so if the reinforcement is placed before setting the hollow cylinder, it will lack self-sustainability and will be difficult to stabilize. It was difficult to construct because the striations tended to collapse. Furthermore, even if you try to run the piping for equipment such as electricity in a direction perpendicular to the length of the hollow cylinder after setting it, the upper and lower layers of the slab are thin, so reinforcing bars, etc. will get in the way, making it difficult to do the piping afterwards. This was impossible and the piping had to be installed before setting the hollow tube.

In addition, in the case of an embedding material in which the iron plate is made into a hollow cylinder,
Since the iron plate is thin, it may become punctured or cracked by external impacts. Therefore, in rare cases, rainwater or construction water from these defective parts may enter the hollow cylinder, and the stored water may leak onto the ceiling surface after the building is completed.

On the other hand, when using synthetic resin foam embedding material, it is possible to maintain sufficient strength while maintaining the ratio of non-concrete parts of the slab, and to facilitate the installation of the embedding material and the reinforcement arrangement. The current situation is that embedding materials are particularly required to have a good shape in combination with reinforcing bars.

<Purpose> The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a concrete slab cast on-site that can facilitate construction and reduce costs.

<Structure> The structure of the cast-in-place concrete slab of the present invention to achieve the above object includes, in the cast-in-place concrete layer, an embedding material of an inverted polygonal column made of synthetic resin foam; For embedded materials consisting of a support member with legs that supports and holds the embedded material in a position inside the concrete layer, and a fixing member that is inserted through the embedded material and fixes the embedded material at a position inside the concrete layer. the fixing devices are sequentially arranged between the intermediate connecting bars, the side surface of the embedded material is a vertical plane parallel to the vertical part of the intermediate connecting bars,
The upper and lower surfaces of the embedding material form horizontal planes parallel to the upper and lower horizontal distribution bars, and the embedding material is further characterized in that a slope portion is formed between the side surface and the upper and lower surfaces.

<Example> Next, an example of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a polygonal column embedding material made of a synthetic resin foam, for example, a polystyrene foam, and is composed of an inverted polygonal column having sloped portions A at the diagonal portions. The embedded material 1 includes a supporting member 21 and a fixing member 22.
It is firmly supported and held inside the concrete layer by an embedded material fixing device 2 consisting of. That is,
The implant 1 is placed on a support member 21 having legs 21a, and an insertion shaft 22a of a fixing member 22 fixed upright on the support member 21 is inserted into the insertion portion 11 thereof. The upper surface is pressed and fixed by a holding plate 22b having a stabbing blade-like locking part 22c provided on the head of 22a. The legs 21a of the support member 21 are designed to prevent stains on the directly finished ceiling due to rust at the tips after dismantling the demolding temporary formwork P for pouring concrete. It is desirable to apply rust treatment. As a specific example of this anti-rust treatment, a synthetic resin cap 21c is attached to the tip of the leg 21a.
In some cases, the tip is covered with a metal oxide, or the tip is plated directly (see Figure 2).

The fixing tool 2 and the embedded material 1 supported and held by the fixing tool 2 require necessary reinforcing bars such as the lower end main reinforcement 31, the lower end distribution reinforcement 31', the intermediate connecting reinforcement 32,
Together with the upper end main reinforcement 33 and the upper end distribution reinforcement 33', they are arranged at predetermined intervals between the intermediate connection reinforcements 32 in the concrete layer cast on site, and the side surface B of the polygonal embedded material 1 is the intermediate connection reinforcement. The embedded material 1 forms a vertical plane parallel to the vertical part 32' of the reinforcement 32, and the upper and lower surfaces C and C' form horizontal surfaces parallel to the upper and lower horizontal distribution reinforcements 33' and 31'. A slope part A is formed between the upper and lower surfaces C and C', and an inclined widening part D is formed in the intermediate part 4 between the embedding materials 1 and 1 at the slope part A of the embedding material 1 up and down.
is configured.

If such an inclined expansion part D is configured, a continuous arch structure will be formed between the intermediate parts 4, 4, so that the slab strength of the upper and lower parts of the embedded material 1 can be reinforced, resulting in very excellent performance. This means that you will be able to demonstrate your abilities.

Next, as a construction method for a concrete slab having the above structure, first, on the demolding temporary formwork P that has been laid, insert portions 11 such as the ends of the embedded material 1, the middle part, the boundary between the embedded materials, etc. The supporting member 21 and the fixing member 23 for the insertion shaft 22a are erected correspondingly (see FIGS. 4 and 5). This fixing member 23 is composed of a support ring 23a that is brought into contact with the demolding temporary formwork P, and a double-threaded bolt 23b that is screwed up to the middle of the inner diameter part of this support ring 23a. When fixing, after fixing the support ring 23a with a screw formed on the inner diameter from the back side of the demolding temporary formwork P using bolts 24, washers 25, nuts 26, etc.
Both threaded bolts 23b are screwed onto the upper part of the support ring 23a, the support member 21 is placed directly above this, and the flanged sleeve 27 with an internal thread formed therein is inserted into the through hole 21b on the upper surface of the support member 21 and screwed onto the both threaded bolts 23b. This is done by tightening this (see Fig. 2).Next, the insertion shaft 22a is screwed into the flanged sleeve 27 and fixed in an upright position (see Fig. 4), and the implant 1 is fixed. , the insertion shaft 2 is inserted into the insertion portion 11.
2a and place it on the support member 21. Then, a presser plate 22b having a stabbing blade-like locking part 22c is inserted into the head of the insertion shaft 22a, and is tightened with a nut 22d to fix the implant 1 (fifth
(see figure). In this state, concrete is poured, the embedding material 1 and the embedding material fixing device 2 are surrounded with concrete, and after the poured concrete has hardened, the dehulling formwork p is
By demolishing it, the concrete slab mentioned above can be formed. Although the explanation was omitted above, the lower end main reinforcement 31 and the lower end distribution reinforcement 3
Reinforcements such as 1' are applied at appropriate times during the work of fixing the embedded material 1. Furthermore, it is also possible to use a presser plate 22b that does not have the locking portion 22c.

In addition, regarding the above-mentioned assembly structure for supporting the embedded material during construction, the fixing member 23, the supporting member 21, the flanged sleeve 27, and the double-threaded bolt 23 are used.
It is preferable to use one in which the insertion shaft 22a and the insertion shaft 22a are assembled in advance and integrated.

As the fixing member 23 for fixing the implant 1, for example, as shown in FIG. 6, a plurality of elastically deformable divided pieces 2 are provided at the tip of the insertion shaft 22a in the axial direction.
2e, the split piece 22e is elastically deformed and inserted into the hole P' of the demolding temporary formwork P made of wood or the like, and the non-return claw 22f at the tip prevents it from coming off;
As shown in Fig. 7, a screw nail 2 is attached to the tip of the insertion shaft 22a.
2g or a screw nail that is screwed into the demolding temporary formwork P, and as shown in Fig. 8, the tip of the insertion shaft 22a can be divided into multiple parts in the axial direction and expanded outward. The divided piece 22h is configured to be detachable by screwing together, and the divided piece 22h separated from the insertion shaft 22a is inserted into the hole P' of the demolding temporary formwork P.
Various methods can be adopted, such as one in which the insertion shaft 22a is screwed together after this is expanded outwardly by the impact of the pin 22i and fixed.

Furthermore, the supporting member 21 on which the embedded material 1 is placed is not limited to the one shown in the figure, but may have various structures as long as it can support the embedded material 1 while floating on the temporary formwork P for removal. can be adopted.

Furthermore, as the synthetic resin foam forming the embedding material 1, in addition to the above-mentioned polystyrene foam,
It is also possible to use foams made from polyethylene, polypropylene, polyvinyl chloride, copolymers mainly composed of these, and the like.

<Effects> According to the cast-in-place concrete slab of the present invention constructed as described above, a fixing device for embedded material, which is composed of a supporting member with legs and a fixing member, is disposed within the concrete layer. It has a structure in which the embedded material is supported and held at a position inside the concrete layer by a supporting member, and a fixing member is inserted through the embedded material to fix the embedded material at a position inside the concrete layer, It is easy to use a support with legs to embed the embedded material inside the concrete layer, and because the fixing member is inserted through the embedded material, the support can be placed above the panel. At the same time, by fixing the fixing member above the panel, a structure is created in which construction can be easily carried out in which the embedded material is supported and fixed while floating on the panel.

A fixing device for the embedding material and a polygonal column embedding material made of synthetic resin foam are sequentially placed between the intermediate connecting bars, and the sides of the polygonal embedding material are connected to the vertical parts of the intermediate connecting bars. Since it forms a vertical plane parallel to the embedding material, it is possible to increase the spacing between the embedded materials without significantly reducing the non-concrete area in the concrete slab compared to conventional hollow tube embedding, making it possible to install intermediate connecting bars. It is also possible to install intermediate connecting bars having a stable shape that have been manufactured in advance at a factory before setting the embedding material, making it easier to set intermediate connecting bars in a stable state. In addition, when setting the embedding material later between the intermediate connecting bars, it is stable because the embedding material is made of lightweight synthetic resin foam and its upper and lower surfaces have horizontal planes parallel to the upper and lower horizontal distribution bars. Due to its shape, it is easy to handle and set up.
Furthermore, since the above-mentioned embedded material forms a slope between its side and upper and lower surfaces, the intermediate part between the embedded materials is expanded at an angle at the top and bottom, and there is a continuous arch between them. structure, the slab strength can be increased, and excellent performance can be demonstrated. Therefore, not only can the indoor space be made larger, but reinforcement work is also easier, making a significant contribution to reducing the cost of concrete slabs. In this invention, the embedding material is made of synthetic resin foam, so even after the embedding material has been set, for equipment piping such as electricity, it is necessary to remove part of the embedding material as necessary. By notching or perforating the section, piping can be freely installed while maintaining the necessary concrete cross section with thin sections at the top and bottom. In addition, the direction of the notches and holes in the embedded material can be made diagonally, allowing piping to be installed over the shortest possible distance, which is useful for saving on piping during construction of concrete slabs cast on-site. Furthermore, since the embedding material is made of synthetic resin foam, the inconvenience that rainwater or construction water may accumulate in the embedding material is also eliminated, which is advantageous.

[Brief explanation of the drawing]

The figure shows an embodiment of the invention.
The figure is a sectional view, Figure 2 is a front view showing the mounting state of the support member, Figure 3 is an exploded perspective view of the main part of the fixture for embedded material, and Figures 4 and 5 are perspective views showing the construction in progress. , FIGS. 6 to 8 are sectional views showing other embodiments. 1... Embedded material, 2... Fixture for embedded material, 21...
...Supporting member, 23...Fixing member, 22a...Insertion shaft, 31...Lower end main reinforcement, 31'...Lower end distribution reinforcement,
32...Middle connecting bar, 33...Top main bar, 33'
...Top end distribution bar, 4...Middle part, A...Slope part of embedded material, B...Side surface, C, C'...Top and bottom surface, D...
Inclined expansion section, P...Temporary formwork for removal.

Claims (1)

[Claims] 1. An embedding material made of synthetic resin foam in the form of an upside-down polygonal column in a concrete layer poured on-site, and a supporting member with legs to support and hold the embedding material in a position inside the concrete layer, and the embedding material. Embedded material fixing devices, each consisting of a fixing member that is inserted through the concrete layer to fix the embedded material at an internal position in the concrete layer, are sequentially arranged between the intermediate connecting bars, and The side surface is a vertical plane parallel to the vertical part of the intermediate connecting bar,
A concrete slab cast on-site, characterized in that the upper and lower surfaces of the embedded material form horizontal planes parallel to the upper and lower horizontal distribution bars, and the embedded material further forms a sloped portion between the side surface and the upper and lower surfaces. .