JPH056613B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for embedding metal fittings in a concrete frame, and particularly relates to a method for embedding metal fittings in a concrete frame suitable for building a nuclear power generation facility. .

[Technical background of the invention]

In order to weld supports for piping within the building of nuclear power generation equipment, 20,000 to 30,000 embedded metal fittings are generally embedded in the concrete frame that constitutes the building.

Conventionally, the method of burying such embedded metal fittings was
This was done as shown in the figure and FIG.

That is, in the formwork 2 before concrete pouring, in which a large number of reinforcing bars 1, 1... are stretched,
A flat embedded metal fitting 3 with studs 4, 4... projecting from the back surface 3b connects its plate surface 3a to the back surface 2 of the formwork 2
It is attached by nails 5, 5, . . . so as to be joined to b. After that, concrete is poured into the formwork 2, and after the concrete hardens, the formwork 2 is removed to form a concrete frame.

[Problems with background technology]

However, as mentioned above, if the embedded metal fitting 3 is fixed to the formwork 2 with the nails 5, the embedded metal fitting 3 will be damaged by the vibration of the vibrator used to make the concrete flow evenly during concrete pouring. It may fall off from the formwork 2, the plate surface 3a of the embedded metal fitting 3 will no longer be flush with the surface of the concrete structure, and it will sink into the concrete.
The plate surface 3a of the embedded metal fitting 3 may not be exposed on the surface of the concrete body, the embedded metal fitting 33 may be completely submerged in the concrete, causing damage to the frame, or even the piping support may be welded to the embedded metal fitting 3. There were various problems that made it impossible to do so.

[Purpose of the invention]

It is an object of the present invention to provide a method for embedding an embedding metal fitting in a concrete structure, which eliminates the drawbacks of the conventional method described above and allows the plate surface of the embedding metal fitting to be flush with the surface of the concrete structure. .

[Summary of the invention]

The present invention provides a screw shaft that is inserted through the embedded metal fitting and protrudes from the plate surface of the embedded metal fitting, and a through hole through which the screw shaft is inserted is formed in the formwork, and the screw shaft is inserted from the back side of the formwork. Insert it into the through hole, screw a nut onto the screw shaft that protrudes from the surface of the formwork, and fix it so that the plate surface of the embedded metal fitting is connected to the back of the formwork. Then, concrete is poured into the formwork, The feature is that after the concrete hardens, the nut is removed from the screw shaft and the formwork is removed from the embedded fittings.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings.

FIGS. 3 to 5 show the embedded metal fitting 6 used in the burying method of the present invention, and this embedded metal fitting 6
The shape differs depending on the working load, but in general,
It is formed of a rectangular or square plate with a thickness of 15 to 30 mm and a side of 150 to 500 mm. Studs 4 are protruded from the back surface 6b of the embedded metal fitting 6, and the diameter and number of the studs 4 vary depending on the load used. On the other hand, two through holes 7, 7 are bored in the embedded metal fitting 6, and each through hole 7 has a
A screw shaft 8 protruding toward the surface (plate surface) 6a side of the embedded fitting 6 is inserted through it. Head 8a of this screw shaft 8
is located on the rear surface 6b side of the embedded metal fitting 6, and is welded to the embedded metal fitting 6 to prevent rotation. This screw shaft 8
The length of the mold is approximately 150 mm so that the formwork 2 can be fixed with good stability.

The procedure for manufacturing a concrete body by embedding the above-mentioned embedding metal fittings 6 in the concrete body will be explained with reference to FIGS. 6 and 7.

First, a large number of reinforcing bars 1, 1... are arranged vertically and horizontally, the embedded metal fitting 6 is positioned at the required position, and a wire or the like is wound around the stud 4 to attach the embedded metal fitting 6 to the reinforcing bar 1.
Temporarily fasten. On the other hand, a through hole 9 into which the screw shaft 8 is inserted is drilled in advance in the formwork 2 so that the embedded fitting 6 is in the correct setting position, and the screw shaft 8 is inserted into the through hole 9 of the formwork 2. Insertion, back side 2a of formwork 2
is joined to the surface 6a of the embedded metal fitting 6, and a nut 10 is screwed onto the screw shaft 8 to integrate the formwork 2 and the embedded metal fitting 6.

After that, concrete is poured into the formwork, and in order to make the concrete in the formwork 2 flow evenly,
Vibrate the concrete using a vibrator, etc. However, since the embedded metal fitting 6 is firmly connected to the formwork 2 by the screw shaft 8 and the nut 10, the embedded metal fitting 6 may be damaged by vibrations from a vibrator or the like.
There is no risk that the metal fitting 6 will fall off or the embedded metal fitting 6 will be displaced.

Therefore, after the concrete hardens, if the nuts 10 are removed from the screw shafts 8 of the embedded fittings 6 and the formwork 2 is removed, the embedded fittings 6 can be moved against the surface of the concrete structure.
Since the plate surfaces 6a are flush, piping supports can be welded without any problem in the construction of a building for a nuclear power generation facility. Note that, prior to this welding, each screw shaft 8 is cut out from its base using a grinder or the like.

In the above-described embodiment, the embedded metal fitting 6 has been described as having a plate shape, but the embedded metal fitting 6 is not limited to the shape of the back surface 6b as long as the plate surface 6a is formed in a flat shape.

〔Effect of the invention〕

As explained above, in the method of embedding an embedded metal fitting in a concrete frame according to the present invention, the screw shaft inserted into the embedded metal fitting is provided to protrude from the plate surface of the embedded metal fitting, and the screw shaft is inserted into the formwork. Form a through hole for insertion, insert the screw shaft into the through hole from the back side of the formwork,
Screw a nut onto the screw shaft protruding from the surface of the formwork and fix it so that the plate surface of the embedded metal fitting is connected to the back of the formwork. Then, pour concrete into the formwork, and after the concrete hardens, tighten the nut. Since the formwork can be removed from the embedded metal fittings by removing it from the screw shaft, the embedded metal fittings will not fall off or shift from the formwork during concrete pouring, and the plate surface of the embedded metal fittings will not be removed from the concrete frame surface. can be made flush with Therefore, when 20,000 to 30,000 embedded metal fittings are used, for example, in nuclear power generation equipment, piping supports and the like can be constructed with good workability and according to design requirements.

Moreover, it is sufficient to simply provide a through hole in the embedded metal fitting, and there is no need for special processing such as welding in advance, so that the embedded metal fitting can be fixed in an extremely simple process.

[Brief explanation of the drawing]

Figure 1 is a back view showing the conventional embedded metal fitting embedding method, Figure 2 is a side view of Figure 1, Figure 3 is a perspective view of the embedded metal fitting used in the present invention, and Figures 4 and 5.
The figures are a front view and a side view of Fig. 3, Fig. 6 is a partially cutaway perspective view showing an embodiment of the embedding metal fitting embedding method according to the present invention, and Fig. 7 is a side view of Fig. 6. . 1... Reinforcing bar, 2... Formwork, 3, 6... Embedded metal fittings, 8... Screw shaft, 10... Nut.

Claims (1)

[Claims] 1. In the method of embedding metal fittings into a concrete structure, in which the metal fittings with a plate surface are embedded in the concrete structure so that they are flush with the surface of the concrete structure,
A screw shaft inserted through the embedded fitting is provided protruding from the plate surface of the embedded fitting, and a through hole is formed in the formwork through which the screw shaft is inserted, and the screw shaft is inserted into the through hole from the back side of the formwork. Insert the screw through the formwork, screw the nut onto the screw shaft protruding from the surface of the formwork, and fix it so that the plate surface of the embedded metal fitting connects to the back of the formwork. Then, concrete is poured into the formwork and the concrete hardens. A method for embedding in a concrete structure, characterized in that the rear nut is removed from the screw shaft and the formwork is removed from the embedding fittings.