DE2604037A1 - METHOD AND DEVICE FOR FORMING A CONCRETE COMPONENT WITH INNER PASSAGE CAVITIES - Google Patents

Description

BY 3531

A / S Norcem, Oslo / Norway

Method and device for forming a concrete component with internal through-cavities

The invention relates to a method and an apparatus for forming concrete components with internal through-cavities or holes.

In order to save concrete and to make concrete components lighter in weight, it is generally known to use passage cavities, especially in the case of prefabricated ceiling components. A typical component of this type is a rectangular one subdivided element which has longitudinal cavities, usually of circular cross-section. These Voids can well be more than 50 # of the total volume form, and the saving in material consumption is correspondingly high with additional easier handling and reduced stability requirements, which results from the weight reduction.

So far it has proven to be practical to use such elements as prefabricated elements only in larger ones To manufacture concrete product factories. The main reason for this lies in the fact that only the economically well established Industries can cope with the substantial investments that are required to run a rational and develop economic production; Added to this is the fact that these industries have a large and own neighboring sales market. The transport of concrete elements over long distances is expensive and requires good roads as well as expensive equipment. the

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Concrete elements also require extensive and powerful Crane systems at the construction site.

One method of forming cavities or holes in concrete components of the type mentioned above is to extrude very dry concrete (little water to avoid collapse) around pipes which are continuously pulled out of the concrete, thereby leaving voids. However, the facilities required for this concreting technique are very expensive and wear out quickly; Although dry concrete hardens quickly, there is always the risk of local collapse, which has a very unfavorable effect. Despite the expensive facilities and the risk of rejects, this is still one of the most widely used methods today.

Attempts have also been made to form cavities by inflating a rubber hose from which the air is let out after the concrete has hardened, whereupon it is then pulled out. However, this method has not been able to establish itself in practice.

In a third known method of forming cavities, plastic tubes with carbamide foam are used filled to form cylindrical rods and to embed them in the mold in the concrete. This is one of the most economical and effective methods that is widely used

Another widely used method of forming cavities, as in the first-mentioned method, is to extrude concrete around pipes; in this case However, the drill hole is filled with spheres of expanded clay or the like, which form the pipes as thick strands in the concrete leave until it has hardened. Then the elements are cut off and flipped over, so that the beads that cannot adhere to the concrete, fall out and be reused. Usually 85 # of the beads will be

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reused what resulted in a consumption of about 15 # egg yolks results.

All of the aforementioned known methods have the common fact that they are either due to the consumed Material or are relatively expensive due to the expensive facilities. There is also the need to that the manufacture of such components in concrete product factories takes place as prefabricated elements, which results in expensive transport, lifting capacities and facilities.

The main object of the present invention is therefore to provide a method for forming concrete components with internal To create cavities, the material consumption of which is reduced to a minimum and therefore very economical and in which the associated device is simple, reliable and cheap and also easily transportable.

Furthermore, a method (and a device suitable for this) is to be created which can be carried out on the spot can be.

The obvious economic benefits obtained by such a process are also offsetting smaller suppliers will be able to carry out this procedure.

The invention is based on a method for forming a concrete component with internal through-cavities, wherein a starting side layer of the concrete component is formed in a mold and thereon in the vicinity of this a side layer core-forming means arranged in terms of position, then the remaining parts of the component are cast and Finally, at least parts of the core-forming agent are removed when the concrete component has hardened at least partially is.

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The invention is essentially to be seen in the fact that at least one relatively thin-walled, tubular holder, which has perforations or other suitable air vents in its wall, is suspended between the opposite end walls of the casting foria above the said starting side layer and is suspended in particle material as the core-forming means this holding element is filled through one of its end openings with the aid of an air stream, whereupon the mold is fully poured and then the particulate material is removed again after at least partial hardening of the concrete component through the same end or the opposite end of the holding element with the aid of an air stream .

Preferred materials for a flexible, tubular holding element are perforated polyethylene films, woven or non-woven textiles, paper webs or the like. Material, while the particulate material, which is to be filled into the holding element or in the holding elements, preferably consists of spheres of expanded polystyrene cellular plastic.

A preferred device for carrying out the method according to the invention which contains a casting mold is characterized in that at least one holding element made of relatively thin-walled, tubular, air-permeable material between opposite end walls of the casting mold is suspended in which openings are provided through at least one end wall and that a fan and piping are provided for conveying particulate matter by means of an air stream from a container into the suspended holding element and from there back into the container.

The invention is described in more detail below with reference to an exemplary embodiment illustrated in the drawing, which however does not represent any limitation. The drawing, which is purely schematic and simplified, shows in

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Pig. 1 is a partial perspective view of a typical concrete component produced by the method and made with the device according to the present invention;

Pig. 2 shows a longitudinal section through an inventive Device for producing a concrete component with a cavity provided therein (corresponding to the illustration in Pig. I);

Pig. 3 shows a plan view of the device according to Pig. 2;

Pig. 4 is a simplified side view of the mold according to Pig. 2 and 3 in connection with additional device parts;

Pig. 5 views of a preferred assembly of the core-forming tubes according to the invention;

Pig. 6 shows a view of a favorable feed unit for the tubes or hoses forming the core.

Pig. Fig. 1 illustrates a typical concrete element 1 which has a number of spaced apart, longitudinal and through holes or cavities 2 with a substantially circular cross-section and which is produced by the method according to the invention, as will be described in detail below.

According to the Pig. 2 and 3 has a rectangular casting mold IO with internal dimensions that correspond to the concrete element 1 to be produced, opposite end walls 11 and II ¹ with a plurality of laterally spaced, centrally aligned openings 11a and II ¹ a with a diameter that is essentially the same is the diameter of the longitudinal cavities 2 in the element 1.

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A cylindrical sleeve or sleeve 14 is in each opening lla fastened or fitted in the end wall 11 of the form IO, wherein the ends of the sleeve 14 protrude a certain distance beyond the outside of the end wall 11.

In Jfig. Fig. 4 illustrates a loading unit yQ comprising a vertical container or silo 15 communicating through a bottom outlet pipe 15a with an outlet pipe 16a of a ventilator or ventilator 16; Furthermore, an injector 19 is provided in the ventilator outlet pipe directly below the mouth of the bottom pipe 15a coming from the silo. A flexible tube or flexible line 18 forms an extension of the outlet tube 16a and is designed at its distal end so that it fits into the opening 11a in the end wall 11. The silo 15 is filled with a particulate material G, preferably spheres made of expanded polystyrene cell plastic (EP6 spheres), the bottom of the silo container being closable by a flap 25. Return lines or pipes 17 and 20 are branched off from the ventilator outlet pipe 16a on opposite sides of an intermediate flap 26 in the fiohr 16a. The loading unit, which comprises the silo 15, the fan 16 with drive devices (not shown) and the associated pipes 16a, 17 and 20, is constructed in a suitable manner on a base frame 27 provided with wheels in order to be able to transport it easily.

When a typical H concrete element 1 as illustrated in Fig. 1, with the aid of the device described above is produced, then the following process sequence occurs:

At the beginning, a layer of concrete is poured into the mold IO, which is open at the top, up to a level dae coincides with the lower edges of the end wall opening.

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Then a number of core-forming clamping or holding elements 12 in the iOrmabschnitte from a relatively thin-walled flexible pipe (preferably plastic material, such as polyethylene) of substantially the same diameter as the end wall opening in the mold 10 in arranged their position, the corresponding pipe ends through the opposite end wall openings 11a and 11'a hindureh. The polyethylene pipe (PE pipe) is already in advance with a continuous perforation been made to a size that allows air to pass through while facing it wet concrete is essentially impermeable.

Shut-off pieces 13 in the form of a conical sleeve, which is provided at its smaller end with a screen-shaped shield 13a, are fitted into the pipe ends which protrude through the openings of the end wall II ¹ , and they are inserted into these openings (like a can lid or the like .), whereby the end of the pipe section or retaining element 12 is wedged ^{firmly and tightly against the end wall II 1.} On the opposite end wall 11, the pipe ends are inserted through a solid cylindrical collar 14, tightened and folded over or back onto the projecting part of the collar.

When all the PE pipes are suspended in this way, the free end of the flexible pipe 18 (3? Ig. 4-) is fitted into one of the outer end wall openings 11a, the fan 16 is started, the flap 25 is pulled open and when it is open Flap 26, pellets G are blown from the silo 15 through the flexible pipe 18 into the suspended PE pipe 12 which is in communication with the flexible pipe 18; the carrier air flow escapes through the perforations in the tube wall (as indicated by arrows in Fig. K ) and through the screen 13a provided at the other end, the mesh openings being smaller than the beads G. The flexible tube 18 is then

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connected to the next end wall opening 11a, whereupon the previous procedure is repeated. If all PE ears in the I? Orn essentially with EPS beads filled, are, v / ird a slightly conical plug 22 in each end v / and opening 11a inserted so that these openings are closed and at the same time a raised one Pressure is exerted on the EPS beads which are contained in the tubular holding elements 12.

The pouring of concrete into the mold 10 is now completed, with the suspended PE pipes filled with EPS beads (retaining elements 12) acting as core elements that are sufficiently rigid and stable to withstand the pressure of the concrete poured into the mold.

When the concrete in the mold 10 is substantially hardened, the plugs 22 are removed and that flexible pipe 18 is reconnected to the corresponding openings 11a of the end wall 11. The fan 16 is started with the flaps 25 and 26 closed, and due to the suction effect caused by the injector 19 in the Fan outlet pipe 16a is produced, the EPS beads are extracted from the holes or cavities 2, which are now shown in the hard concrete element 1 are formed, sucked back through the flexible pipe 18 and the reversing pipe 20 and then through the reversing pipe 17 is blown into the top of the silo container 15, for a new use. The direction of travel or conveyance of the beads carried along by the air stream through the different tubes is indicated in Fig. 4 by arrows.

In this way, in the method according to the invention, the only material used is that of the PE pipes, which can be left as a skin in the cavities 2 of the element 1.

In order to ensure a quick and correct arrangement of the PE pipes in the casting mold 10, several pipes

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parallel to each other and with the correct spacing ratio, as it is illustrated in the upper part of Fig. 4-, are arranged together, with the tubes below one another are connected at intervals by means of strips 23 of an adhesive tape. In the lower part of the pig. 5 are the Illustrates tubes in the suspended and expanded state. Optionally, a pre-formed steel wire can also be used (not illustrated) can be used as clamping bracing for the suspended holding elements 12.

The perforated PE pipes are preferably drawn off from a spool or roll 12a that is placed on a portable Frame 21, as illustrated in Fig. 6, is supported.

Although perforated polyethylene tubing is a preferred material for the support member forming the core can - as already mentioned above - the latter can also be made of other suitable material, such as paper, woven or non-woven textiles, etc., exist in the form of a flexible tube.

The loading unit 30 does not necessarily have to have the construction shown in FIG. 4, but can also any other suitable shape for conveying the EPS beads into and out of the holding element forming the core. For example, the beads also in the opposite end of the retaining element (opposite to the end into which it is now inserted v / ground) blown into the holding element or there sucked out v / ground.

The polystyrene beads are preferably sieved to a diameter on the order of 5-10 mm and the ball density is preferably 25 kg / m ^. These Density gives sufficient strength without yielding under the weight of the poured concrete. the However, the size and density of the globules mentioned represents

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no limitation, as good results also through The use of larger or smaller beads can be achieved which have a lower or higher density.

Of course, materials other than expanded polystyrene beads can also be used to make the to fill suspended, core-forming holding elements 12, for example expanded clay spheres (Leca spheres) a Type that - as mentioned at the beginning - is used in the prior art.

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Claims (5)

260-037 Claims Method for forming a concrete component with internal Passage cavities, with an initial side layer in a Gußfona of the concrete component is formed and then in the vicinity of this core-forming a side layer Means arranged in relation to the position, then cast the remaining parts of the component and finally at least Parts of the core-forming means are removed when the concrete component is at least partially hardened, thereby characterized in that at least one relatively thin-walled, tubular one is used as the core-forming agent Holding element, which has perforations or other suitable air passages in its wall, between the opposite end walls of the casting mold over the said starting side layer is hardened and part - Chen material is filled into this holding element through one of its end openings with the aid of a stream of air is, whereupon the mold is fully poured and then the particulate material after at least partial hardening of the concrete component through the same end or the opposite end of the retaining element with the aid of a stream of air is removed again. 2. The method according to claim 1, characterized in that a flexible bore made of perforated plastic film (polyethylene film), woven or non-woven textiles, paper webs or the like is used as the holding element. 3. The method according to claim 1, characterized in that beads made of expanded polystyrene * en cell plastic is used as the particle material. 4. The method according to claim 3, characterized in that the beads with a diameter in the order of magnitude of 5-10 mm and the bead density with about 25 kg / nr are selected. 609832 / 03Λ2 5. Apparatus for performing the method according to claim 1, divided into a mold, characterized in that at least one holding element made of relatively thin-walled, tubular, air-permeable material between opposite oath walls of the mold is suspended, in the case of openings through at least one end wall are provided and that a fan and piping are provided for conveying particulate matter by means of an air flow from a container into the suspended holding element and from there back into the Container. 603-3 2/0342 .41 · Blank page