JPH0635733B2 - Lightening construction method for concrete floor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for reducing the weight of a concrete floor.

<Prior art> For making a concrete floor with a hollow part to reduce the weight,
First, there is JIS A6511 “Prestressed concrete plate having a hollow portion in the longitudinal direction manufactured by the pretensioning method”, commonly known as “perforated PC plate”. The example cross section is
Shown in Figure 12.

In addition to the method in which the PC board itself becomes a hollow floor in this way, there is a construction method for making a hollow floor in the field. As shown in Figs. 13 and 14, it uses a thin-walled PC board 1 as an underlay, and vertically and horizontally spaced a box-shaped formwork 2 such as a heavy box, and a longitudinal truss 3 between them. After assembling and assembling the slab upper-side streak 4 as usual, the floor cast-in-place concrete 5 is poured to cover and integrate the whole.

The above is a concrete floor with a hollow part using a prestressed concrete plate that is currently in practical use, but as a device that could not be put to practical use only on the basis of the idea, the present inventor filed an application 5 years ago There is a "concrete slab with a hollow part" disclosed in the official gazette.

As shown in FIG. 15, a unit corrugated sheet, which is a prestressed concrete board containing PC steel wire 6, is laid on the beam as an embedded formwork 7, and all or most of the V grooves are covered with a sealing material 8. The cast-in-place concrete 5 is placed.

The main reason why this idea could not be put to practical use is that it is extremely difficult to manufacture a PC plate having such a large height difference by the sliding molding method developed by the present inventor and manufacturing a PC plate for an embedded formwork. It was that. The method of making a perforated PC board in Fig. 12 is not impossible, but it was an extremely expensive PC board in terms of equipment and efficiency, and could not be put to practical use.

In addition, considering the current situation, there were other difficulties as described below.

<Problems to be solved by the invention> The idea of the present inventor of FIG. 15 five years ago is that the embedded formwork 7 acts as a main material for supporting the weight and load of the concrete floor. However, as described above, there was no practical method for producing a PC board having such a large difference in height.

Since the conventional PC plate was almost flat, it could be molded relatively easily by the casting method or the sliding molding method of the present inventor. However, as shown in Fig. 15, the thin-walled waveform has a height difference of 200 to 4
00mm is also required, the length is as long as 8 to 10m according to the beam interval, and concrete must be molded, demolded and cured without loosening the pretension through the PC steel wire.

The present invention solves such a problem in manufacturing a PC board, and further improves the usage of the PC board as a concrete floor lightweight construction method.

<Means for Solving Problems> The method for reducing the weight of a concrete floor according to the present invention uses a unit concrete corrugated plate made of PC concrete in which both edges of a valley portion are half-divided mountain portions.
Laying them between the beams of the structure being constructed, putting a cover plate or core for creating a hollow part in the above-mentioned valley to form an embedded formwork that will be the main material of the lightweight concrete floor, and laying it on the floor surface A method of casting cast-in-place concrete to integrate it with each of the unit corrugated plates, and the unit corrugated plate having a length that can be bridged between the beams is
The lower formwork with PC steel wire tensioning mechanism has two concrete intermediate positions in the longitudinal direction pushed up by a pair of push-up vibrating devices to place the upper formwork with concrete inlet horizontally, and the lower face of the upper formwork. It is characterized in that it is pressed and oscillated, and it is molded by adding hard concrete.

The floor cast-in-place concrete has a thickness sufficient to integrate the laid-out unit corrugated sheets and is not more than the height of the unit corrugated sheets.

<Working> Conventional PC board manufacturing methods are practically the same as a concrete concrete product: a pouring type, an extrusion type that produces the product shown in FIG. 12, and an upper frame sliding type of the present inventor. Pre-tension
Needed a bench.

In a method that has not been practically used at all, a large number of molds with a PC steel wire tensioning mechanism were prepared and moved in the order of steps.

The present inventor has greatly improved this method, which remained only in books, and improved the efficiency by virtue of the hard concrete oscillating molding technology, which made it the deciding factor for mass production of corrugated PC boards.

Since the unit corrugated sheet peculiar to this invention has halved ridges on both edges, when laid side by side, the halved ridges are joined together to form the ridges, respectively, and are made of cast-in-place concrete to form a flat concrete floor. become. The top of the mountain is a rough surface or a connectable surface with exposed wire mesh and gibber streaks, making it easy to integrate with cast-in-place concrete.

Pre-tensioned PC steel wire passes through the troughs of the unit corrugated sheet, that is, the lower side of the corrugated sheet. Therefore, like the PC sheet used for the conventional floorboard embedded formwork, there is no support between the beams. It has a bending resistance that can be passed over, and after the cast-in-place concrete, its pre-tensioning works to reinforce the floor and prevent cracks.

As described above, the unit corrugated sheet of the present invention has a large corrugated sheet when laid side by side and has the strongest bending resistance in comparison with its own weight, in addition to having the same function as the conventional PC board for buried formwork. It has a planar structure.

When the cast-in-place concrete is placed on the corrugated plate to make the upper surface flat as a floor, the valleys on the upper surface are filled, and the lightness of the corrugated plate is halved. However, in this invention, since the valley is covered with the cover plate in advance, the valley remains as a hollow portion,
Does not lose lightness. In addition to the reinforcing bars above it, the flat cast-in-place concrete layer that integrates each unit corrugated sheet distributes the concentrated load on the floor and prevents the corrugated sheet from buckling, so the minimum weight and maximum strength. It becomes a concrete floor with.

<Examples> Fig. 1 is a cross-sectional view of a concrete floor to which the present invention is applied, in which B is a large beam of a building and b is a small beam in the middle. The girder B is made hollow by using the embedded molds M and m for the beam developed as “method”. Needless to say, the present invention can be applied to the floor between conventional beams.

In this embodiment, when the unit corrugated sheet 10 of the present invention is bridged between the beam embedded molds M and m, and the cast-in-place concrete 20 is placed thereon, the beam embedded molds M and m are also placed on the beam embedded molds M and m. Although it is cast, the beam is not related to this invention.

FIG. 2 is a partially enlarged view of the AA cross section of FIG. The unit corrugated plate 10 has a half-divided mountain portion 12 on both sides of a single valley portion 11 and a width of 1
m, height 250 mm. In this case, the mountaintop 12a is a rough surface, and when the concrete is poured and molded, which will be described later, the surface of the floor surface cast concrete 20 is a rough surface that is hardened at the curing place by pressing an upper mold bar or lattice on this surface. Easy to join.

The PC steel wire 13 for pre-tension passes inside the valley 11,
A compressive stress is generated on the entire length of the unit corrugated plate 10. Each valley 11
A cover plate 14 is successively contacted between the upper slopes on both sides of the corrugated plate, and the cover plates 14 are passed over each other with no gaps therebetween to form a hollow portion 15 over substantially the entire length of the corrugated plate 10.

About the full length is that part of the hollow part 15 may be filled with cast-in-place concrete 20 for the convenience of design.
In this embodiment, although not shown, there is no cover plate 14 on the beams on both ends, and the cast-in-place concrete is filled up to the bottom of the valley 11.

The cover plate 14 is a 500 mm x 500 mm thin steel plate that is curved in the middle and
It was fitted between 11 roughened upper slopes, and the edges were touched one after the other without any gap, but the cover plate 14 put a thick paper on a jumping bar as long as it had strength to support cast-in-place concrete. It can be a simple one.

In addition, like the conventional PC board, inside the unit corrugated board 10,
A horizontal streak 16 crossing the vertical PC steel wire 13 is inserted. It is also conventional to assemble vertical and horizontal reinforcing bars 17 entirely before pouring of cast-in-place concrete 20.

The cast-in-place concrete 20 integrates the unit corrugated sheets 10 group to disperse the concentrated load on the floor surface and transmit it to the corrugated sheet group which is the main material, and it needs a sufficient thickness to prevent the buckling. The thickness may be equal to or less than the height of the unit corrugated plate 10. In FIG. 2, the height of the corrugated sheet 10 is 250 mm, while the thickness of the cast-in-place concrete 20 (above the peak 12a of the corrugated sheet) is 60 mm.

3 to 5 show cross sections of a unit corrugated plate 10 according to three embodiments. Fig. 3 is the same as Fig. 2 and has a height of 200 mm, and Fig. 4 is the same as 3
A horizontal streak 16 is attached to the connectable surface of the summit 12a at 00 mm,
6a is an example. Fig. 5 is a little different, and a unit concrete plate is placed by putting a hard concrete between the upper and lower molds and applying vibration and pressure.
When molding to 10, use the core 19 of the cross section as shown in the figure only for the part where the bending moment in the center part of the length is large, and between the upper surface and the lower surface of the center part of the upper mold, This is an example in which the raising part 18 is integrally formed.

By adding such a raised portion 18 to the central portion, the bending resistance of the unit corrugated sheet 10 itself is significantly improved. After molding, the core 19 is pulled out to the side or made of styrofoam,
You may leave it in the middle.

Comparing the waveforms in FIGS. 3, 4, and 5 with those in FIG. 15, the unit corrugated sheet 10 of the present invention has a large pitch in relation to the height, and its crests and valleys have wide flat surfaces. The cross-sectional area of the upper and lower flat parts, which is useful for bending resistance of the floor, was enlarged, and the cross-sectional area of the inclined part was reduced.

Also, both edges of the unit corrugated plate 10 are not half valleys as shown in FIG. 15 but half peaks 12. This is because the adjacent half-divided mountain portions 12 are directly integrated by the cast-in-place concrete 20.

The unit corrugated sheet of the above-mentioned embodiment was previously developed by the present inventor and has a patent application (Japanese Patent Application No. 61-108712 and Japanese Patent Application Laid-Open No. 62-264913).
It was manufactured efficiently and cheaply by the concrete plate manufacturing method and equipment.

The point is briefly explained.

In FIG. 6, 21 is a lower frame, 22 is an upper frame, and the unit corrugated plate 10 is provided between them.
Contains hard-mixed concrete molded into. The concrete is dropped from the inlets 23 (with a grid for rough surfaces) on the left and right of the upper frame 22, and the inside of the frame is filled with vibrations without gaps.

Fig. 7 shows the side view of Fig. 6, but the lower frame 21 is still transportation equipment.
I just got to the molding position on 24. Since the lower frame 21 is as long as 10 m or more, it cannot be placed on a normal vibrating table for forming hard concrete. Then, a pair of front and rear push-up and vibrating devices 25 are used to press the stationary upper frame 22 to bring it to the state shown in FIG.

FIG. 8 is a view showing a mechanism for holding the pre-tension (pre-tension) on the PC steel wire 13 of the lower frame 21, in which the screw rod 26 towed the PC steel wire 13 is fixed to the outer frame by the nut 27, It can be transported to and from. Although not shown, the unit corrugated plate 10 is surrounded and molded by both end plates 28, 28 and a bottom plate 29.

However, the manufacturing method and device of the unit corrugated plate of the present invention are not limited to the above.

Next, as a caution when carrying out the present invention, FIGS. 9 and 10 show the processing when mass-produced unit corrugated sheets are laid side by side and there is an excess or deficiency with respect to the floor width. Fig. 9 shows the case of shortage.
It suffices to place a flat joint plate 30 on the gap generated between the two and cast the cast-in-place concrete 20. There is no problem in strength unless the gap is too large.

FIG. 10 shows an example in which both edges of the unit corrugated sheet 10 are cut off little by little to form a narrow unit corrugated sheet 10 ', and the cut 31 is used as a connecting edge to contact the adjacent corrugated sheets 10, 10. This is an application example in which the field engineer dared to put the cast-in-place concrete 20 into the corrugated plate valley portion without using the cover plate 14 because the wave height is low.

FIG. 11 is a diagram showing effects other than the lightweight of the lightweight floor according to the present invention, in which the hollow portion between the unit corrugated plate trough portion 11 and the cover plate 14 is made to extend over the entire length, and large and small pipes 32 and wiring are provided therein. Can be threaded. In addition, when the ceiling plate 33 is provided on the lower side, the bottom of the corrugated plate mountain portion can also be used as a communication hole. It is easy to make the pipe outlet 34 in the cast-in-place concrete 20.

Although a few examples have been described above, the present invention is a well-known technique of a construction engineer who carries out the present invention, and various changes depending on the situation of the site, such as the wave shape of the unit corrugated plate, the number, the cover plate, and the molding equipment, It goes without saying that it can be applied.

<Effects of the Invention> This invention has completed a method of putting the idea of FIG. 15 into practice, which could not be achieved five years ago.

Among thin-walled PC boards that are difficult to mass-produce, it is especially difficult to use a unit corrugated sheet with a large difference in bottom, but this invention has two long-standing forms, a moving formwork with a PC steel wire tensioning mechanism, a technology that was forgotten by the world. A new hard concrete oscillating molding technology, in which the support is vibrated, was added to make this a practical floor material.

Then, both edges of the unit corrugated sheet are not half valleys as in the case of FIG. 15 but half crests, and the whole corrugated sheet is integrated, which is significantly advantageous in terms of strength and appearance. .

According to the present invention, a thin-walled PC board, which was conventionally an embedded formwork that simply eliminates the hassle of assembling and removing formwork and supports between beams to create a concrete floor, became the main material for the concrete floor for the first time. The full-scale lightweight construction method was opened.

Since the cast-in-place concrete layer that integrates the unit corrugated sheets laid out is the same as in the prior art, on-site work is easy. And the finished floor is a corrugated sheet that is light and resistant to bending,
The weight of the concrete floor was practically maximized because it works in cooperation with the cast-in-place concrete layer that distributes the load and prevents the corrugated sheet from buckling.

As a by-product, the unit corrugated plate and the hollow part between the cover plates are suitable for floor wiring and piping, and will be suitable as a floor for concrete construction in the future.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a floor of an embodiment of the present invention, FIG. 2 is a transverse sectional view of the same, FIGS. 3, 4 and 5 are sectional views of three unit corrugated sheets, and FIG. Fig. 7 is a side view of the state before the upper and lower frames are combined, Fig. 7 is a side view of the state before the same, Fig. 8 is an explanatory view of the vertical cross section of the lower frame, and Fig. 9 shows the unit corrugated plates between the beams. Sectional view showing the usage of the joint plate when the width is insufficient, FIG. 10 is a sectional view showing a measure when the width is also excessive, FIG. 11 is a sectional explanatory view showing a method used for wiring and piping, Fig. 12 and below are prior arts, Fig. 12 is an end view of a perforated PC board, Figs. 13 and 14 are perspective views and sectional views of a method of embedding a large number of box-shaped forms, and Fig. 15 is the present inventor. 5 is an explanatory diagram of the idea 5 years ago, in which 10 is a unit corrugated sheet, 14 is a cover sheet, and 20 is cast concrete.

Claims (2)

[Claims] 1. A unit corrugated plate made of PC concrete in which both edges of a valley portion are half-divided peak portions is laid side by side between beams of a structure being constructed, and a cover plate or core for forming a hollow portion is formed in the valley portion. Is used as an embedded formwork that will become the main material of the lightweight concrete floor, and a reinforcement method will be laid on it to place cast-in-place concrete for the floor surface and integrate with each of the above unit corrugated sheets. The above unit corrugated plate with a length that can be passed over is placed horizontally with the upper formwork with concrete input port, and the lower formwork with PC steel wire tension mechanism pushes up a pair of two intermediate positions in the longitudinal direction. A method for reducing the weight of a concrete floor, which is characterized in that it is pushed up by a shaking device and pressed against the lower surface of the above-mentioned upper mold, and then shaken. 2. The method according to claim 1, wherein the floor cast-in-place concrete has a thickness sufficient to integrate the unit corrugated sheets laid out and the height of the unit corrugated sheet is high. A method for reducing the weight of concrete floors that is less than or equal to