JPS6033668B2 - Manufacturing method of steel plate coated concrete plate - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a steel plate-coated concrete plate, and in order to reliably integrate the concrete without straining the coated steel plate, the plate is held horizontally when welding a large number of anchor steel rods to the steel plate. The entire lower surface of the steel plate is immersed in water, and when pouring concrete onto the steel plate, the main method is to pass beams upward to hold down the steel plate at key points, and after the concrete has hardened, the concrete is removed. This is a characteristic feature.

If the surface of concrete can be reliably covered with a steel plate,
It combines the advantages of both, making it suitable as a material for civil engineering and construction.

However, large members and heating members are not suitable for coating steel plates with adhesives. The present invention has previously developed a concrete formwork for slidingly forming a PC concrete slab, but the lower frame is over 100 meters long, and the surface must be covered with a steel plate. It is difficult to make this in one piece, so it was divided into 3 skin units, but the bottom frame of the unit is 3 skins x 2, and the thickness is 15
It is an enemy. The steel plate is about the size of a 6-year-old willow and is relatively thin, so it deforms even under its own weight. Formwork covered with deformed steel plates cannot be slid to form PC concrete slabs that require dimensional accuracy. In addition, the joint between the steel plate and concrete must be reliable and must be able to withstand the temperature rise caused by steam curing. In addition, since many products of the same shape are manufactured, an efficient manufacturing method is required to ensure that the quality is always the same. The present invention has solved these problems as follows.

That is, first, a coated steel plate that has been previously formed into the desired shape is
Lay the back side up horizontally and submerge the entire underside in cold water to prepare for welding. A large number of anchor steel rods are then welded evenly to the back surface of the steel plate, that is, the surface facing upward. Arc welding is generally used. Since many short welds are performed on one side of a relatively thin steel plate, the steel plate would normally be deformed, but as mentioned above, the entire bottom side is immersed in cold water, so the deformation is extremely slight. After welding the anchor steel plate in this way, the steel plate is inserted into the concrete receiving frame in the welding position, that is, with the back side with the anchor facing up. The receiving frame consists of an underframe portion that receives the steel plate, and a side frame, but if the edge of the steel plate is folded so that it also functions as a concrete side frame, the side frame at that part Not necessary. Once the steel plate is fitted into the receiving frame so as to serve as the bottom plate of a normal formwork, a beam material is passed over it and fixed at both ends using any method.

Then, key points of the steel plate are pressed against the receiving frame by a push rod lowered from the beam, concrete is poured in and solidified to a required size, and the push rod is removed. Of course, after that, the solidified concrete is removed from the receiving frame together with the integrated steel plate, or the receiving frame is disassembled. Next, using the drawing,
Embodiments of this invention will be described.

Figures 1 and 2 show lower formworks 1 and 1' for sliding forming of PC concrete plates as two rows of steel plate-coated concrete plates produced by the manufacturing method of the present invention.

In either case, a large number of unit materials of the same shape are made and fixed in series to form a long lower frame of, for example, about 100 pieces.
The upper steel plate la, 1'a is connected to the lower concrete material lb, 1
'b is not adhesively bonded, but a V-shaped anchor steel rod 2 (see Figures 3 and 4) is welded to the steel plate la side, and this is buried in concrete to mediate the fixation of the two. Note that the first
Hole 2, drawn only in the diagram, is a curing steam hole that runs vertically through the concrete material lb. These lower formworks (lower frame) 1,1
The dimensions of ' are, for example, steel plate la with a thickness of 6 mm, concrete material lb with a thickness of 15 mm, and the vertical and horizontal dimensions of 2 m x 3.

This invention does not apply to devices that can easily join steel plates and concrete materials by applying adhesive. The manufacturing method includes the step of melting countless anchor steel rods 2 onto a coated steel plate la.

It is common knowledge among mechanical engineers that if numerous local welds are applied to only one side of a steel plate, the steel plate will warp like a wok, so using that steel plate as the top plate of the lower frame for emotional forming was a reckless idea. It looked like. However, as mentioned above, this problem was solved by welding the entire lower surface of the steel plate immersed in cold water, and FIG. 3 shows an example of the setup for welding. A support member 3a on which a steel plate la is placed horizontally is provided in a shallow and wide water tank 3, and cold water is poured so that when the steel plate la is placed on this, the entire lower surface is immersed in water, but the upper surface is not submerged. In order to maintain such a water level, as in the embodiment shown in FIG. If you do this, you can achieve your purpose with the simplest structure. In addition, since the steel plate la is tilted slightly, there is no problem with errors such as the unwelded end part rising slightly above the water surface, or conversely, the top surface being covered with water. FIG. 6 shows the state in which the V-shaped anchor steel beam 2 is arc welded to the steel plate la. It is up to the welding engineer to decide whether to lightly apply the weld bead W on both sides, or only on one side, or to add a large weld bead W. In any case, steel plate la
It has been confirmed through many experiments that if the weld is water-cooled as shown above, residual stress in the welded area is unavoidable, but deformation that poses a practical problem does not occur. In addition, it is also possible to use a well-known receptacle stud as the anchor steel beam 2 and weld it one after another using a stud welding machine.

Measures to prevent deformation during welding include common sense methods such as the restraint method, reverse strain method, and stepping stone welding method, as well as special methods such as immersing the lower part of the thick base material in water, or applying localized methods to the area or back surface during welding. Cooling with leaking cloth or other materials has traditionally been done.

However, common sense would not suggest that there would be an effective deformation prevention method under the harsh conditions of welding an anchor rod to the entire surface of one side of a 3-6 wall thick and wide steel plate, where deformation is most common due to welding heat. , it was expected that troublesome distortion correction work would be required after welding. However, the above-mentioned method of floating a steel plate on the surface of the water yielded unexpectedly good results. However, the above method does not completely prevent deformation.

However, in the case of this invention, even if there is some deformation, during subsequent concrete pouring, it is brought into contact with the concrete in the corrected state and fixed as is. Fourth
Figure 5 shows an example of the concrete placement setup.

Place the steel plate la with the back side welded to the anchor steel plate 2 facing up.
It is fitted into the receiving frame 7 for concrete injection. Receiving frame 7 is
It consists of a side frame 7a made of channel steel erected in a U-shape, an end plate 7b, and an underframe section in which channel steel 7d assembled vertically and horizontally is placed between two outer 1-section steels 7c. There is nothing that corresponds to the bottom plate of a normal formwork, and the steel plate la fitted there serves as the bottom plate and receives the poured concrete. A beam 8 is passed between the side frames 7a, 7a on both sides of the receiving frame 7, and both ends are fixed with screws 9 via a spacing piece 9a. Therefore, the beam 8 is suspended over the steel plate la placed on the bottom surface. The shape of the steel plate la is suppressed in some places by the pushers 10 lowered from the beam material 8, and even if the steel plate la is slightly deformed, it can be moved to the required position of the underframe.
By attaching a mark to the top surface of the shaped steel 7c and channel steel 7d, the horizontality is corrected. In this state, when concrete is poured into the receiving frame 7 and solidified, the steel plate la is flattened and integrated with the solidified concrete, and is finished to the required dimensions.

In the illustrated embodiment, channel steel is used as the beam 8, erected in a U-shape, and a reinforcing plate 11 is applied only at the position where the push rod 10 is attached.

A bolt that is not threaded in the leg of the push rod 1 passes through holes in the upper and lower brim of the beam 8, as shown in FIG. 5, and is dovetailed with a nut 12 welded to the lower hole. A rubber hose 13 is fitted around the outer periphery of the unscrewed leg portion of the push rod 10 and the portion buried in concrete. This rubber hose 13 may be left in the concrete when the push rod 10 is pulled out after the concrete hardens. By turning the hexagonal head of the pusher with a wrench, the lower end of the pusher 10 will forcefully press the steel plate la against the support frame 7 side underframe, and if you turn it in the opposite direction and pull it up a little from the solidified concrete, it will no longer be possible to turn it. Pull out the legs.

Note that the rubber hose 13 may be made of other materials since the push rod 10 is made of steel and is a covering used because it easily adheres to concrete. Fill the holes left after pulling out with mortar if necessary. When fitting the steel plate la into the bottom of the receiving frame 7, the receiving frame side frame 7a
Square washers (Fig. 5) are welded intermittently to the lower part of the inner surface of the steel plate la, and by attaching the side frame 7a and 1-shape steel 7c using bolts and nuts 15 and 16 on the outside, the twill part of the steel plate la becomes 1-shape. It is possible to suppress floating from the upper surface of the steel 7c.

This eliminates the need to arrange the pusher 10 on the periphery of the steel plate la, which is effective from a practical standpoint. In addition, in this embodiment, in order to make the steam hole 20 run vertically through the concrete material 1b', a core support hole 17 is provided in the end plate 7b, and a square plate 18 (FIG. 5) that forms a packing receiving recess is attached to the inner outer periphery of the core support hole 17. ) is there.

The cores 19 are indicated by chain lines, and although only two are shown in FIG. 4, they are steel pipes or vinyl chloride pipes passed through the opposing support holes 17 of both end plates 7b. This core 19 is extracted at the early stage of concrete hardening. In concrete slabs made in this way, the steam heat raises the temperature of the concrete material, and that heat is transferred to the steel plate, so the deformation that occurs when the steel plate is heated first does not occur. In the above example, the concrete plate 1 shown in Fig. 1 was used as an example, but in the case of the concrete plate 1 shown in Fig. 2, the welding water tank 3, the partition plate 5
Even if the rib part of the steel plate 1'a is submerged in water by placing a rubber plate on its inner surface, there will be no problem as long as the rib part of the steel plate 1'a is submerged in water, as long as the upper surface of the rib part is devised to prevent water from entering. There is no problem if you make a base frame part.

Also, the steel plates la and 1'a in Figures 1 and 2 are concrete materials l.
In the case where the side frame 7a of FIGS. 4 and 5 is bent downward to cover the side surfaces of b and 1'b, the side frame 7a shown in FIGS. 4 and 5 becomes unnecessary.

At this time, in order to fix both ends of the beam member 8, it is sufficient to use the 1-section steel 7c or a separately provided fixing member. In addition, the manufacturing method of the present invention may be varied in various ways without changing the gist thereof, depending on the shape and dimensions of the intended steel plate-coated concrete slab, factory conditions, etc., at the discretion of the field engineer.

This invention uses a simple water cooling method in which a wide steel plate is held horizontally and only one side is immersed in a cold water surface, and even if countless anchor steel bars are welded to the top surface, welding distortion can be minimized. When concrete is poured, the beams and push rods passed over the receiving frame are used to correct slight distortions and make it to the regular dimensions, so when it is fixed to the solidified concrete, it is finished to the regular dimensions. The push rod not only corrects the welding distortion of the steel plate, but also plays the important role of continuing to hold the steel plate at key points during concrete curing and preventing the effects of volume changes during solidification. That is, the present invention has overcome the double problems of welding distortion of the steel plate and volumetric change of concrete during solidification, and has been able to maintain the dimensional accuracy of the concrete covered steel plate.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views of two examples of steel plate-coated concrete slabs to which the present invention is applied, Figure 3 is a cross-sectional view of one example of the welding setup between the steel plate and anchor steel rod of Figure 1, and Figure 4 The figure is a perspective view (partial) of an example of the setup for pouring concrete onto a steel plate, FIG. 5 is an elevational view thereof, and FIG. 6 is an explanatory view of an example of an anchor steel welding part. la...Steel plate, lb...Concrete material, 2...Anchor steel rod, 3...Water tank, 7...
... Receiving frame for concrete injection, 8 ... Beam material, 1
0...Push stick. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1 The process of placing the coated steel plate horizontally with the back side up and immersing only the entire bottom surface in cold water. The process of welding a large number of anchor steel rods evenly to the back of the steel plate. The process of placing the steel plate with the back side facing up in concrete. Steps of fitting the steel plate into the receiving frame, passing the beam material on top of it and fixing both ends; pressing key points of the steel plate onto the receiving frame using push rods lowered from the beam material; pouring concrete and solidifying it to the required dimensions; A method for manufacturing a steel plate-coated concrete slab, comprising the step of extracting the push rod from the solidified concrete.