DE2431501A1 - CASTING METHOD AND DEVICE FOR THE PRODUCTION OF PREFABRICATED CONCRETE ELEMENTS - Google Patents

Description

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PROF. DR. DR. J. REITSTÖTTER 243 I 501

DR.-ING. WOLFRAM BUNTE DR. WERNER KINZEBACH

D-BOOO MÜNCHIN 40. BAUBRBTRABB * «1 · FlWNRUF (O ··)» 7 · ■ BS ■ TBLBX VIIBIOa IBAR D POSTAL ADDRESSi D-BOOO MÜNCMBN 4S. FOBT COMPARTMENT 7BO

Munich, July 1, 1974 M / 15 332 M / 15 353

John ZACHARIASSEN,

30 Krogshojvej,

DK-2880 Bagsvaerd, Kopenhaeen / DENMARK

* ι

Casting method and apparatus for making j

prefabricated concrete elements

For the casting of components, structural elements and other items, such as walls, stair parts or the like., In prefabrication from unreinforced and reinforced concrete and other materials, there are a number of methods that are based on the fact that the elements in the casting either in vertical or are in a horizontal position. For vertical molding

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the following two basic procedures are known:

1. The separate molding of each element and

2. the simultaneous or continuous casting of the elements side by side with heavy, vertical steel dividers between them the elements (group casting).

The following three basic processes are known for horizontal casting:

1. The separate molding of each element;

2. The molding of the elements one on top of the other and

3. the extrusion.

While the vertical cast can be achieved with relative ease. Areas of high quality and - as far as group casting is concerned - this leads to a minimum of work must be done the elements usually remain in the molds for at least a few hours before they are removed from the molds for further curing Shapes can be removed.

With vertical casting, therefore, the cost of the molds and associated equipment make up a significant part of the total manufacturing costs.

The horizontal separate or single casting brings with it relatively low mold costs, high labor or labor costs and considerable spatial expenditure. The surface quality of the upper sides will normally not be comparable to the surface quality of a vertically cast element. The casting of the elements on top of one another (stack casting) requires much less space than the horizontal single casting. However, the manual labor required is still very considerable, and it is

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comparatively difficult to obtain surfaces of high quality, as is possible with horizontal single casting.

Extrusion processes can only be used where very simply shaped elements with a constant cross-section can be cast, as in the case of ceiling parts. While the space requirement is considerable, this is necessary Handicraft very limited.

If you look at the extrusion process, which is only for a lot Simple elements can be applied, once starting, it can generally be said that the vertical casting is particularly cost-intensive, while the horizontal casting is particularly labor-intensive.

Eb is known (US-PS 2 6 867) to apply a vacuum to the concrete in order to remove most of the excess Water from the poured concrete to achieve stronger concrete and reduced production time; this for the first time in the mentioned patent specification is from the 1936. The patent emphasizes application to horizontal surfaces such as floors, and has been since then Procedures have for the most part been applied to soils. It is true that the application of the method on vertical surfaces, insofar as a non-horizontal application is concerned, was however in the Industry made only insignificant use.

When casting walls in vacuum molds vertically, for example, the filter cloth is on the inner surfaces of the molds quickly worn out by erosion during pouring of the concrete. This disadvantage alone could be general Prevented the use of vacuum treatment during the vertical pouring of concrete parts.

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Furthermore, the application of negative pressure in the vertical casting of large elements does not in itself give them sufficient immediate strength so that the shapes can be formed immediately after the vacuum treatment. Also in In such cases, the chemical reaction between the cement and the water must largely proceed before a sufficient one internal strength is achieved to allow removal of the mold.

With the previously known methods it was therefore not possible in particular to produce large, multi-faceted reinforced concrete elements or components in a really large-scale production process with a process duration or a process cycle in less than a few hours (for each shape).

The invention eliminates the disadvantages of the prior art and provides a method with the help of large planes or reinforced concrete elements with many bevels or shaped in some other way with one process cycle or a process time (for each mold used) of 10 to 30 minutes depending mainly on the thickness of each Elements together with its total volume can be produced.

The invention enables the production of elements with surfaces of high quality with low labor costs and low costs for molds and associated facilities and - in the case of the production of elements with congruent or nearly congruent front and rear surfaces - under very modest space requirements, thus taking advantage of the vertical and the horizontal font .

The manufacturing method according to the invention and the way in which

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it can be carried out with minor variations, is explained in more detail below with reference to the accompanying drawings. These show in FIGS. 1 to 17 the individual stages of two embodiments of the method.

A lower molded part 2 is arranged and fastened on a tiltable plate 1 (FIG. 1), above the lower molded part 2 a membrane 3 is attached, which can be a polyethylene film and with the help of negative pressure through slits in the Surface of the lower mold part is generated (Fig. 2), is held on the lower mold part 2.

Then a reinforcement Ί is placed (Fig. 3), on which an upper molded part 5 is placed, which is connected to the lower molded part 2 (Fig. 10 ⁾ .

Then the plate and the mold or molded parts are combined into one brought inclined position (Fig. 5).

The flow of element 6 is shown in FIG. The concrete is introduced into the mold by means of a funnel 7.

After the completion of the casting, the element 6, which is held in a vertical position, is applied over the surface of the Upper mold part 5 applied a negative pressure and vibrated at the same time (Fig. 7). An airtight seal 8 is during this process stage attached to the upper edge of the element.

After the treatment described so far, the element that is still on the plate is rotated into a horizontal position (FIG. 8), whereupon the element 6 with the help of the negative pressure further applied to the upper mold part 5 with simultaneous detachment from the lower one Molded part 2 by switching the negative pressure applied there to atmospheric

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Pressure or slight overpressure is raised and conveyed away.

Finally, the element 6 is placed on a pallet, one as a base Serving mold or another freshly cast element set down (Fig. 9) and then by switching the negative pressure applied to the upper mold part 5 to atmospheric pressure or a slight overpressure from this upper mold part 5 solved.

In the manner described, one on top of the other can be more identical or nearly identical elements with congruent and nearly congruent surfaces in a continuous manner and take place as an integrated procedural stage.

According to the invention, however, in the case in which the elements have congruent and almost congruent surfaces (front surface and rear surface), the elements can also be placed on top of one another or stacked directly on the tiltable plate.

Figures 10 and 11 show that after the casting of an element and its fixation on the plate 1 in an inclined position the upper mold part 5 is peeled off by reducing the negative pressure applied thereto to atmospheric pressure or a slight overpressure switches.

A membrane 9 is then placed tightly on the fresh casting 6 (if necessary with the aid of an applied negative pressure (Fig. 12)), whereupon a reinforcement 10 is attached for the new element (Fig. 13).

Then the upper mold part 5 is attached (Fig. 1Ί), and the

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The new element 11 is cast (FIG. 15).

After the Quss, the plate 1 with the two elements in tilted an upright position, an airtight seal 12 placed on the upper edge of the newly cast element 11, and a negative pressure is then applied to the newly cast element 11 and, if necessary, vibrated at the same time (FIG. 16).

The same sequence of process steps can be repeated a few more times until the entire stack of elements is lifted off the plate to allow it to harden (Fig. 17).

In the described embodiment of the invention Procedure is the steel reinforcement for an item to be cast prior to attaching the top molding in place brought. However, the upper molding can also be provided with hooks or magnets, so that the reinforcement grid below can be attached to the upper molding.

The tiltable plate 1 does not need to be tiltable about a central axis, as shown in the drawings. she can also be tiltable about one or more axes lying inside or outside the plate, as long as the desired inclinations can be realized.

The vacuum treatment can be continued, while the treated member is rotated to a horizontal position as well as during the time during which it is held in any inclined or horizontal position.

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Claims (1)

M / 15 332 PATENT CLAIMS Casting method for the production of prefabricated concrete elements, characterized in that the casting is carried out in an inclined Location of the mold under vibration performs the casting or the castings are then brought into a vertical position and then subjected to a vacuum treatment and finally formed out of the mold in a horizontal position. 2. The method according to claim 1, characterized in that one for lifting the casting in a molded part for Purpose of transporting it to a place where it can harden, using the same vacuum that is used to remove it excess water from the fresh casting. 3. The method according to claim 1, characterized in that the lower molding for casting a new concrete element used a fresh casting. M. Device for the production of prefabricated cast concrete elements, in particular for carrying out the method according to one of claims 1 to 3, characterized by a tiltable plate (1) carrying the mold (molded parts) (2, 5 ), at least one vibrator and a device for - 8 -409884/0470 M / 15 332 Remove excess water from the fresh one (s) Qiessling (s) (6). 5. Apparatus according to claim k, characterized in that the upper mold part (5) has a suction device for lifting the fresh Qießlings (6) and transporting it to a point where it can harden with the aid of negative pressure. 6. Apparatus according to claim 4, characterized in that for the casting of concrete elements with congruent or almost congruent front and rear surfaces, the lower mold part for an element to be cast (11) from the top casting (8) of a stack of fresher, on the plate ( 1) and the lower mold part (2) of resting Qießlinge is formed. - 9 -93 409884/0470 Blank page