Title:
Method for Vertically Extruding a Concrete Element, Device for Producing a Concrete Element, and Wind Turbine Generator Tower Produced by This Method
Kind Code:
A1


Abstract:
Device for producing an elongated concrete element extending in the vertical direction, for example a tower of a wind turbine generator system, comprising an inner casing and an outer casing, the inner casing and the outer casing being configured in such a way that between the inner casing and the outer casing there is an interspace, which is of a height that is less than the height of the concrete element to be produced. A number of pumps are used, in order to pump concrete into the interspace. The pumps are designed in such a way that the concrete can be introduced at high pressure in such a way that the interspace is filled with concrete and that the concrete element is forced vertically upwards out of the interspace during the hardening of the concrete. As the concrete element rises, an attachments, that later serves for pulling up and mounting various elements, is transported upwards.



Inventors:
Grob, Gustav R. (Carouge, CH)
Keller, Martin (Gersau, CH)
Application Number:
12/065268
Publication Date:
12/25/2008
Filing Date:
08/28/2006
Primary Class:
Other Classes:
249/48, 264/32
International Classes:
E04H12/12; E04B1/18; E04G13/02
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Primary Examiner:
PAINTER, BRANON C
Attorney, Agent or Firm:
MCCARTER & ENGLISH, LLP (CITYPLACE I 185 ASYLUM STREET, HARTFORD, CT, 06103, US)
Claims:
What is claimed is:

1. Method for vertically extruding an elongated, itself in a vertical direction extending, cylinder shaped concrete element (20), with the following steps: providing an inner casing (12), providing an outer casing (11), wherein between the inner casing (12) and the outer casing (11) an interspace (16) is formed, which has a height (H), that is less than the height (H1) of the concrete element (20) to be finished, introducing the concrete (21) in a lower area of the interspace (16), wherein the concrete (21) is inserted with high pressure so that the interspace (16) is filled with concrete (21) and that during the hardening of the concrete (21), the concrete element (20) is being extruded vertically upwards out of the interspace (16) characterized in that the concrete (21) is introduced in more than one place in the lower part of the interspace (16) and that on the concrete element (20) in an upper part an attachment (24) is placed, which is being raised upwards by the pushing out of the interspace (16) of the concrete element (20).

2. The method according to claim 1, characterized in that during the introduction or before the introduction, the concrete (21) is provided with enforcement elements, wherein preferably synthetic, glass-steel, or carbon fiber are used as enforcement elements.

3. The method according to claim 1, characterized in that the concrete element (20) is produced seamlessly from the concrete (21) and its height (H1) increases as long as concrete (21) is introduced in the lower part of the interspace (16).

4. The method according to claim 1, characterized in that internally or externally running tensioning means (25, 28) are fitted on the attachment (24), wherein a preferably triangular arrangement of tensioning cords (25) acts as tensioning means.

5. The method according to claim 4, characterized in that, during the extrusion out of the interspace (16), the vertical alignment of the concrete element (20) is controlled through controlled tensioning of the tensioning means (25, 28).

6. The method according to claim 1, characterized in that the means (28, 31) are fitted on the attachment (24), so that, after achieving the height (H1) of the concrete element (20) to be produced, construction parts can be pulled upwards.

7. The method according to claim 1, characterized in that, means are fitted on the attachment (24) so that construction parts can be fitted.

8. The method according to claim 1, characterized in that the introduction of concrete (21) is controlled so that the concrete element (20) rises vertically.

9. The method according to claim 1, characterized in that the inner and/or outer casing (11, 12) is made so that the cross section of the rising concrete element (20) can be changed.

10. The method according to claim 1, characterized in that, in a preparing step, a foundation of concrete is provided, which is either arranged so that the inner casing (12) and the outer casing (11) can be fixed on this foundation, or arranged so that an integral part of the foundation acts as inner casing (12) and only the outer casing (11) must be fixed on this foundation.

11. The method according to claim 4, characterized in that an electro-optical measuring device is used during the vertical extrusion, so that a deviation form the vertical direction can be detected, and thus, during the vertical extrusion, by means of the tensioning means (25, 28) a corresponding correction is conducted.

12. The method according to claim 1, characterized in that during or after the vertical extrusion: outside on the cylindrical concrete element (20) a temporary shell, preferably a tubular shell is fitted, and/or inside in the cylindrical concrete element (20) a temporary shell, preferably a tubular shell is fitted, so that suitable environmental conditions are provided for the hardening of the concrete.

13. The method according to claim 4, characterized in that the temporary shell(s) will be pulled from the ground during the extrusion.

14. Device for producing on location of an elongated, itself in a vertical direction extending concrete element (20), with with an inner casing (12), an outer casing (12), wherein the inner casing (12) and the outer casing (11) are made so that between the inner casing (12) and the outer casing (11) there is an interspace (16), which has a height (H), that is less than the height (H1) of the concrete element (20) to be finished, characterized in that several pumps (17) are provided for the introduction of the concrete (21) in more than one place in lower areas of the interspace (16), the pumps (17) are placed so that the concrete (21) can be introduced with high pressure in such a way that the interspace (16) is filled with concrete (21) and that, during the hardening of the concrete (21), the concrete element (20) is extruded out of the interspace (16) vertically upwards, and that on the concrete element (20), in an upper area, an attachment (24) is fitted, which is being raised upwards by the pushing out of the interspace (16) of the concrete element (20).

15. The device according to claim 14, characterized in that means (15, 17, 18) are provided, so that the concrete (21) can be introduced in more than one place in the bottom part of the interspace (16), wherein preferably a centering means is used, so that the pressure in the bottom part of the interspace (16) can be controlled, that rises the concrete element (20) vertically.

16. The device according to claim 14, characterized in that means are provided so that during the introduction or before the introduction, the concrete (21) can be provided with enforcement elements, wherein preferably synthetic, glass-steel, or carbon fiber are used as enforcement elements.

17. The device according to claim 16, characterized in that the means (34, 35) are placed so, that iron bars or wire (32) as Monier-steel is inserted from below in the interspace (16) and will be shifted upwards with the concrete element (20).

18. The device according to claim 14, characterized in that the inner casing (12) and the outer casing (11) are made so that they can be connected with a foundation (13, 14) on which the concrete element (20) is to be produced, whereby the inner casing (12) and the outer casing (11) are tightly connected to the foundation (13, 14).

19. The device according to claim 14, characterized in that it comprises a concrete foundation, which features a cylindrical concrete wall, which acts as inner casing, and that the outer casing (11) is made so that it is connected with the concrete foundation, wherein the outer casing (12) is connected tightly with the foundation.

20. The device according to claim 14, characterized in that the device comprises a control (40) and tensioning means (25, 28) are provided on the attachment (24), wherein, during the extrusion out of the interspace (16), through controlled tensioning of the tensioning means (25, 28), the vertical alignment of the concrete element (20) can be controlled by means of the control (40), wherein tensioning means (25, 28) relate to inner and/or outer tension cords.

21. The device according to claim 14, characterized in that the device comprises a temporary inner and/or outer shell, preferably a tubular shell.

22. Wind turbine generator tower with an elongated, itself in a vertical direction extending, concrete element (20), is extruded vertically in a continuous extrusion process from between an inner and an outer casing (11, 12), wherein the concrete element comprises an attachment (24), which during the extrusion process acts for the tensioning of the concrete element (20) and after the hardening of the concrete element (20) is suitable as lifting means (31,33, 36) for construction elements (50) of the wind generating turbine, which are to be fixed on or to the concrete element (20).

23. Wind turbine generator tower according to claim 22, characterized in that it has a homogeneous composition through recrystallizing of clinker components of the cement used as part of the concrete (21).

24. Wind turbine generator tower according to claim 22, characterized in that construction parts (50) of the wind turbine generator, like a gondola, a generator, or wind sails for example, can be lifted to the upper end of the concrete element (20) with the lifting means (31, 33, 36).

Description:

This present patent application claims the priority of the PCT application PCT/EP 2005/009319, which was filed on Aug. 30, 2005, on behalf of the above mentioned applicant.

Objects of the invention are a method and a device for vertical extrusion of a concrete element according to the preamble of claim 1 and 14 respectively, and a correspondingly produced wind turbine generator tower according to the preamble of claim 22.

The construction of elongated, in vertical direction extending concrete elements is a challenge in different areas of building construction. Among the techniques known so far, one has always proceeded in a similar manner. To begin the construction work, a foundation is embedded into the ground. On the foundation, a first construction stage emerges, as a casing is filled with concrete which hardens after a certain time. After the first stage hardens, the casing is removed and fitted at the upper end of the hardened concrete element and is again filled with concrete. This process is repeated until the required height is reached.

To simplify this procedure, so-called climbing or sliding casing is used. Usually one needs at least an auxiliary crane to raise and place elements again.

The mentioned methods are especially complicated in case of conical towers whose diameter decreases at top. Furthermore, the concrete must be lifted or pumped to according heights by special devices.

At each construction stage, after the filling of the casing, the work has to be interrupted until the concrete hardens and the casing can be removed again.

Another building construction method is that concrete structures are vertically extruded in place in a continuous procedure, as rudimentary exemplified in the patent specification GB 619048 from 1949. This approach seems not to have proven itself, since for more than 50 years, this issue has not been taken up or further developed.

Another well-known building construction method is that the concrete elements are not cast on location with the aid of casings, but are delivered precast. Thus a first element will be placed on the foundation created earlier. The prefabricated elements are successively stacked up until the required height of the structure is reached. Thus, depending on the size of the elements, complex logistics is required for the transportation of prefabricated concrete elements. In addition, the elements must be brought to their corresponding place and connected together, partially at extreme heights, with expensive special cranes.

These methods have the disadvantage that they are either relatively complicated and expensive, or that they are not applicable in practice, which specially applies to the vertical extrusion process. Especially for wind turbines, this results in a very expensive system, and thus the price of electricity produced with this system is also relatively high.

Furthermore one should bear in mind that in some areas the transportation of prefabricated concrete elements is not possible or hardly possible. In such areas wind turbines and other standing vertical concrete elements have to be constructed conventionally step by step with casings.

The present invention is now pursuing the goal of further improving the known building construction techniques for vertically self extruding concrete elements and to significantly reduce the building costs of such constructions.

Furthermore, it is an object of the invention to be able to produce particularly cost-effective wind turbines.

The solution of this problem is provided

    • by the process through the features of the characterizing portion of claim 1;
    • by the device for producing an elongated, in a vertical direction extruding concrete element through the features of the characterizing portion of claim 14; and
    • by the wind turbine generating tower itself through the characterizing portion of claim 22;

The present invention solves the problem in that, for the vertical extrusion of an elongated, itself in a vertical direction extending concrete element, an inner and an outer shutter is provided, wherein between the inner casing and the outer casing an interspace is made, that has a height which is less than the height of the concrete element to be produced. In this interspace, at several places of the lower area, concrete will be pumped at high pressure in such a way that the interspace will be filled with concrete and that, during the hardening of the concrete, the concrete element will be forced upwards out of the interspace. Furthermore, an attachment is fitted on the concrete element, which is transported upwards by the growth of the concrete element.

This has the advantage that, after a construction stage, one does not have to wait the hardening of the concrete before the casing can be removed and newly placed and fitted on the hardened concrete. By pumping in of the concrete at several places, the concrete element extending itself in vertical direction can be finished with high quality and stiffness. Furthermore, this has the advantage, that in a certain time more concrete can be introduced. In addition, the exact vertical growth of the concrete element can optionally be controlled by targeted control of the concrete flow.

By the use of the attachment, one can dispense with the use of a large crane or breakdown crane, since the attachment allows all elements, which will be required during or after the construction phase, to be carried up.

According to the invention, the otherwise normal procedural steps are greatly reduced.

Furthermore, fewer supplies and consumable materials are required at the construction site.

Advantageously, fast hardening concrete or concrete with accelerator will be deployed. A combination of fast hardening concrete and accelerator is also possible.

Advantageously, at introduction or before introduction, the concrete will be fitted with enforcement elements, wherein preferably plastic, glass, steel or carbon fiber is used as enforcement element or Monier iron, respectively armored steel is deployed.

This has the advantage that the tensile force sensitive concrete is reinforced. Plastic, glass, steel or carbon fiber enforcement elements can all absorb tensile forces in the structure and thus provide the required stiffness.

Advantageously, the concrete element will be seamlessly produced from concrete, since its height increases continuously as long as concrete is introduced at the bottom area of the interspace.

This has the advantage that the work progress does not have to be interrupted several times. Through the production of the concrete element “monolithically”, the stiffness of the construction can be additionally increased.

On the attachment, which is raised to the top by extruding the concrete element out from the interspace, interior or exterior tensioning means can be fitted. Construction components of the concrete element (for example components of a wind turbine) can be pulled to the top before or after reaching the end height (H1).

This has the advantage that, during subsequent work stages, a working platform is available, with whose help for example the generator housing of a wind turbine can be mounted on the concrete element. Besides, tensioning means can be fixed on the attachment, in order to control the vertical alignment of the concrete element.

Advantageously, the introduction of the concrete and/or the tension on the tensioning means is controlled so, that the concrete element rises vertically, even if for example wind load acts on the concrete element.

This has the advantage that movements, which the concrete element makes during the construction phase due to winds for example, can be compensated by selective control of the insertion of concrete and/or by selective control of the tension of the tensioning means.

Preferably, a collar-shaped or belt-shaped element is put around or fitted while pextruding the concrete element out of the interspace.

Advantageously, the inner and/or outer casings can be produced so, that the cross-section of the growing concrete element can be changed.

This has the advantage for example, that, due to a lower self-weight, the upper area of the concrete element can be produced with a lower wall strength. Thus for example, the consumption of materials can be reduced.

It is an advantage of the invention that, through the extrusion, seamless towers, columns, posts or the like with longitudinally constant cross section or with variable cross-section can be produced.

Further advantages arise directly form the description and the associated drawings.

In the following, the invention will be described in detail by exemplary embodiments and with reference to the drawings. Which show:

FIG. 1A a first device according to the invention, in a schematic, sectional side view;

FIG. 1B the first device according to the invention, in a schematic sectional view from above;

FIG. 2A a first step of the process according to the invention, in a schematic sectional side view;

FIG. 2B a second step of the process according to the invention;

FIG. 3 a first device according to the invention, for introducing the concrete at several places with several pumps in a schematic top view;

FIG. 4 a second device according to the invention, for inserting the concrete at several places with several pumps in a schematic top view;

FIG. 5 an anchorage of the concrete element to the foundation with the aid of anchors in a schematic sectional view;

FIG. 6 the engagement of a fixation element in a cavity in a wall of the concrete element in a schematic sectional view;

FIG. 7 an anchorage of an attachment on a concrete element, according to the invention, in a schematic sectional view;

FIG. 8 a schematic sectional view of a growing concrete element with tensioning means and with steering and control means to control the vertical alignment of the concrete element, according to the invention;

FIG. 9 a side view of an extruding tower with a working platform with whose aid, for example, the generator housing can be mounted on the concrete element;

FIG. 10 enforcement means which is inserted into a lower part of the interspace of the casing, in a schematic sectional view;

FIG. 11 an embodiment where a collar or belt shaped ring is put around the extruded concrete element, according to the invention;

FIG. 12 an embodiment of the invention in a top view, where the outer casing has a different cross-section as the inner casing;

FIG. 13A a cross-section through a lower part of a further embodiment of the invention;

FIG. 13B a top view of a lower part of the further embodiment of the invention according to FIG. 13A;

FIG. 14A a cross-section through an outer casing according to a further embodiment of the invention;

FIG. 15A a first step of the process of the invention;

FIG. 15B a second step of the process of the invention;

FIG. 15C a third step of the process of the invention.

Constrictive elements with the same function are provided with the same reference sign in all figures.

In the following, the expression extrusion will be used, even though it is unusual in the field of concrete construction. Typically by extrusion, plastics and other semi fluid thermosetting materials are being pressed through a nozzle in a continuous process. In addition this material—the extrudate—is being melted and homogenized by heating. By the flow through a nozzle, the necessary pressure is provided. After passing through the nozzle, the material solidifies. The cross-section of the geometrical piece thus produced is dependent on the nozzle used, or on a calibration placed behind it.

The invention relates to the production on location, of an elongated, itself in a vertical direction extruding concrete element 20. The invention is especially suitable for the production of towers (for example wind generator turbines), poles, masts and pylons (for example for bridges or boring platforms). Such a concrete element is produced on location, i.e. directly on the destination location. In addition it requires a special device 10 according to the invention, whose details are schematically depicted on FIG. 1A and FIG. 1B, and corresponding equipment. The device 10 comprises an inner casing 12 and an outer casing 11, wherein the inner casing 12 and the outer casing 11 are manufactured so that there is an interspace 16 between the inner casing 12 and the outer casing 11. This interspace 16 is closed on the bottom. On the top end of the casings 11, 12 an exit orifice results.

In the shown embodiment, the casings 11, 12 stand on a foundation 13 or a base. On the foundation 13 or base a foundation step 14 is provided, in order to be able to mount the inner and outer casings 11, 12. The casings 11, 12 have a height H, which is less than the height H1 of the concrete element to be produced. This foundation step 14 is optional, however it provides several advantages, as described in relation to the FIGS. 13A and 15C.

According to the invention, several pumps 17 are provided, in order to be able to insert concrete 21 with pressure in a lower area of the interspace 16. It is important, that the pumps 17 are located so that the concrete 21 can be inserted with high pressure in such a way that the interspace 16 is filled uniformly with concrete 21 from below and that, during the hardening of the concrete 21, the concrete element 20 is pushed (extruded) upwards out of the interspace 16.

Preferably, with regard to the Cariole-force, the concrete is pumped in at an angle, in order to achieve a better homogeneity and to avoid the hardening in the lower filling/pumping area.

Specially preferred are slowly conveying pumps 17 which generate a sufficiently high pressure. Spiral pumps are especially suitable.

On FIG. 1A and in FIG. 1B a feed-through element 15 is to be observed, through which the concrete 21 is extracted in the interspace 16. The extraction direction is indicated by an arrow.

The process of the invention for the vertical extrusion of an elongated, itself in a vertical direction extending concrete element 20 is now closer exemplified in relation to the FIGS. 2A and 2B. An inner casing 12 and an outer casing 11 are provided on location, i.e. on the destination location, as already described in relation to the previous figures. Between these casings 11, 12 there is an interspace 16. The height H of the casings 11, 12 is a lot less than the height H1 of the concrete element 20 to be finished. Typically H is one tenth or smaller than H1. In certain situations, H can be more than one tenth of H1.

According to the invention, after the construction site is prepared on location, the concrete 21 is pumped in a lower area of the interspace 16, wherein the concrete 21 is inserted with high pressure. Thus the interspace 16 is filled from bottom with concrete 21. The top edge 22 of the concrete 21 moves upwards as more concrete 21 is pumped from below. The top edge is indicated on the figures with a subsidiary line 22.

While at the bottom concrete 21 is further pumped, at the area of the top edge 22 the concrete 21 starts to harden. During the hardening of the concrete 21, through the pressure of the concrete 21 pumped in the interspace 16, the concrete element 20 is extruded upwards out of the interspace 16. In FIG. 2B a snapshot is shown, where a part of the hardened concrete 21 already overtops the casing 11, 12 (i.e. H1>H).

By suitable regulation of the pumping power (or by suitable setting of a valve to be used), the upward shift of the top edge 21 can be coordinated with the hardening of the concrete 21.

Through this vertical extrusion process, the concrete element 20 is seamlessly produced from concrete 21 and its height H1 increases as long as concrete 21 is inserted in the bottom of the interspace 16 with sufficient pressure.

In the following paragraphs further aspects and embodiments of the invention will be described, wherein the different variants can be combined with each other at will. First of all concepts will be clarified, as long as they require such a clarifying.

The combination of an inner casing 12 and an outer casing 11, according to the invention, will be hereinafter indicated as casing. Preferably flat, spatially curved or bent boards (such as boards, steel plates, plastic plates) are used for molding and bracing. In a specially preferred embodiment, a concrete element is used as inner casing, as described later. The casing 11, 12 may comprise pillars or pillar elements. In a preferred embodiment, the inner and/or outer casing is adjustable.

Concrete is an artificial solid body out of cement, concrete aggregate (grained stone) and water. It can further contain additional concrete additives and concrete admixtures (for example accelerator). The cement acts as binding means in order to keep together the other components. The stiffness of the concrete is caused by hardening (recrystallisation) of the clinker components of the cement, whereby small crystal pins are being formed, which firmly interlock with each other. The crystal growth lasts an extended period of time, so that the final stiffness is reached long after the extrusion. Through the extrusion process, according to the invention, a continuous (monoblock) concrete element 20 with a very high quality, homogeneity and stability is built.

Fast hardening concrete or concrete with accelerator is especially suitable.

An embodiment of the device 10, that comprises at least one heating element, which is placed so that the concrete 21 hardens faster, is especially preferred. Preferably this ring-shaped heating element sits at the upper end of the casing 11, 12 or in the inside of a hollow tower to be completed.

Concrete can resist to very high pressure, but it fails even at low tensile loads. Therefore, the concrete will be preferably provided with Monier iron (reinforcement steel) and/or fitted with enforcement elements (preferably plastic, glass, steel or carbon fiber). Thus, a concrete element 20 results from bonding construction material, wherein the concrete, according to its material characteristics, absorbs the forces of pressure and the steel and/or enforcement elements, enclosed by the concrete, absorb the tensile forces.

Specially preferred are warmly formed and ribbed concrete steel bars as wire 32 with suitable diameter and suitable length. During the extrusion, this wire 32 can be inserted from top or bottom into the walls of the concrete element 20 (also see FIG. 10).

Construction concrete can be used, which can be produced directly on the constriction site in an own plant or transport concrete can be used which is transported with mixing vehicles from a stationary device and is put for example into a silo 64.

Concrete which has been fitted with enforcement elements is especially preferred for the extrusion. For the sake of simplicity, this kind of concrete will be called fiberconcrete. The use of enforcement elements leads to an improvement of the tensile strength, and thus of the break and crack resistance. Preferably, the fibers will be embedded in the concrete matrix. They act as a king of armoring.

Long or short tensile load oriented fibers can be used. Fiber mats can also be used.

Alkali-resistant glass fibers, steel fibers, carbon fiber and plastic fibers (like for example Polyvinylalcohol, Polyethylene, Polypropylene, Kevlar, Polyacrylacid and its slats, Polyacrylate) are especially preferred as enforcement elements.

Ideal is concrete with a combination of Monier iron and fiber additives. In an actually preferred embodiment, fiber concrete or synthetic concrete (concrete with reactive synthetic additives), which is prestressed with steel braids after the extrusion, is being used.

A top view of a device 10 is depicted on FIG. 3, which allows concrete 21 to be inserted in a bottom area of the interspace 16 at more than one place. In the depicted embodiment, three pumps 17 are provided, each pumping concrete 21 into the interspace 16 through a corresponding feed-through element 15. The pumps 17 are preferably controlled so, that the vertical rise of the concrete element 20 is controllable.

A top view of a device 10 is depicted on FIG. 4, which allows concrete 21 to be inserted in a bottom area of the interspace 16 at more than one place. In the depicted embodiment, one pump 17 is provided that pumps concrete in a distributing ring 18. The distributing ring 18 is connected by radially oriented bar-pipes with the feed-through elements 15, so that each will pump concrete 21 in the interspace 16. Adjustable valves are preferably fitted in the areas of the bar-pipes, which can be controlled so that the vertical rise of the concrete element is controllable. It is to be noticed, that the distributing ring 18 and the other elements of the drawing are pictured in a very schematically.

Other assemblies are also conceivable in order to ensure the uniform insertion of concrete. Adjustable assemblies are preferred.

As described in relation to the preceding embodiments, a foundation 13 or a foundation step 14 is provided at the destination place. This can be done in the usual way. A foundation 13 or a foundation step 14 with means (for example ring-shaped step 14) for fitting the casings 11, 12 is preferred.

In order to ensure a statically stable connection between the foundation 13 and the extruding concrete element 20, Monier iron bars are preferably inserted. On FIG. 5, a cross section of a concrete element 20 is shown that rests on a foundation 13. Tie bars 19 are molded in the foundation 13, which comprise an anchor, which extends in a vertically upward direction. By the insertion of the concrete 21 in the interspace 16 between the casings 11, 12, this anchor 19 will be surrounded by concrete. After the hardening of the concrete, a deep connection results between the concrete element 20 and the foundation.

There are other possibilities to connect the concrete element 20 with the foundation 13. For example, an embodiment is depicted on FIG. 6, by which an anchor 19 is provided with an opening or an ear at the upper end. A vertically upwards extending channel 23 is provided in the wall of the concrete element 20. A steel element (a steel cord 30 for example) runs through this channel 23, which stays under tension or is put under tension (pretension) after the extrusion.

The concrete element 20 comprises respectively an attachment 24. This attachment 24 is preferably mounted from beginning on the raising concrete element 20 and step by step it will be moved upwards as the concrete element 20 rises. Thus cranes and other lifting means are dispensable.

The attachment 24 can overtake one or more of the following functions:

    • it can act as fixation for the tensioning means 31,
    • it can comprise a lifting tool 31, 32, 33 in order to be able to lift up construction parts during or after the finishing of the concrete element 20,
    • it can act as a mounting platform for construction parts.

On FIG. 7, the upper end of a concrete element 20 is shown. An attachment 24 sits on the top edge 22 of the concrete wall 21. The shown attachment 24 comprises ring-shaped inner and outer collars, in order to ensure a secure hold on the concrete wall 21. As schematically shown on FIG. 7, anchors 19 can be used at the upper end of the concrete element 20.

The functioning principle of the tensioning means 31 will now be clarified in connection with FIG. 8. A tower 20 during the extrusion is shown on FIG. 8. The tower 20 comprises an attachment 24. Three steel cords 25 (preferably very hard cords are being used) are fixed to the attachment 24, in order to stabilize in the tower 20 in relation to the vertical direction according to the triangulation principle. This is important, since the tower 20 rises in vertical direction through the pumping in of concrete and is eventually labile or slightly instable. Preferably, during the extrusion it is determined whether the tower is vertical. That can be achieved with a perpendicular or a similar measuring device. In FIG. 8, a light- or laser beam 27 is used as an electro-optic measuring device, which is emitted parallel to a longitudinal axis of the tower by a transmitting/receiving device 26 and reflected on the attachment 24. Such a transmitting/receiving device 26 reacts very sensitively to the smallest deviation from the vertical direction. A control circuit can be constructed, which makes possible, with the use of electronically driven cable winches, the individual adjustment of the tension of the cords 25. The control circuit should preferably be designed so that during the extrusion of the concrete element 20, the steel cord 25 is slowly but continuously unwounded. Specially preferred are tensioning means, which make possible to ensure that the compression load in the wall 21 of the tower is always approximately the same. With growing height H1 of the top edge 22 of the tower 20, the cord tension can be reduced since the self weight of the wall 21 exercises increasing pressure on the concrete in the interspace 16.

The tensioning means are preferably tensioned with hydraulic pumps (as cord lifting equipment).

In the lower part of FIG. 8, a regulating and control means 40 is shown in a very simplified from, which receives signals through a link 41 from the transmitting/receiving device 26 and controls the cable winches accordingly, as hinted by the links 42.

The way the attachment can act as lifting equipment is now elucidated in connection with FIG. 9. In FIG. 9, the tower 20 of a wind turbine generator is shown after extrusion. Lifting means are provided on the attachment 24. In the present case, lifting means is about a (steel) scaffold 36, a cable winch 33 (it can be about a diverter roller in case a cable winch is provided on the ground) and a weight lifting cord 31. Thus one can raise upwards construction parts without a crane or other lifting equipment.

The lifting means can be left on the tower, so that at a later point in time it can be used for maintenance.

It is also conceivable, that a cable winch stands on the ground, and construction parts are raised above by that the weight lifting cord runs around one or more rolls of a pulley. These rolls can be found in this case on the attachment 24.

A basic condition that must be fulfilled, in order for the method of the invention to function, is that the pressure of the pumps 17 has to be sufficient, so that on one hand to fill the interspace 16 of the casing 11, 12 and on the other hand to push upwards the emerging concrete element 20 together with possible additions or superstructures.

The practicability of the invention will be elucidated by reference to the following example. A tower 20 is to be produced, which has an inner diameter D1 of 2.5 m, an outer diameter of 2.8 m and a height H1 of 45 m. Concrete with a specific weight of 2.5 t/m3 is being used. Hence results a weight of approx. 150 t of the tower (without additions or superstructures). The weight of additions or superstructures (for example generator, generator housing, wind turbine, etc.) ads up to 40 t. Hence results a complete weight of 190 t. That exercises a pressure of approx. 16 bar in a lower part of the casing 11, 12. Bearing in mind friction losses and other factors, at pumping, a pressure of 18.5 bars must be provided. When the pump(s) have an aggregate flow rate of 1 m3/h, then it lasts between 50 and 60 hours until the tower 20 is completely extruded.

This example shows that the necessary pressure and flow rate can be achieved with appropriate pumps 17.

During the extrusion, vertically running channels (e.g. channel 23) or other specially formed areas can be provided. For example, the channels can accommodate cables, steel cords, ladders or the like.

As hinted, a longitudinal armoring can be introduced from bottom or top. On FIG. 10 the introduction from below is presented. Adjacent to the concrete element 20 to be produced, a roll 34, with monier iron (e.g. wire) wound up on it, is provided. This wire 32 will be inserted in the interspace 16 preferably through a duct in the outer casing 11. In order to avoid concrete to exit, seal lips 35 or the like can be provided. By the hardening of the concrete 21, the wire 32 will be anchored strongly in the concrete element 20 and through the upwards oriented movement of the concrete element 20, monier iron will be step by step unwound from the roll 34.

In FIG. 11 it is schematically implied, that around the raising concrete element 20 collar or belt-like elements 29 can be laid. Such elements 29 are specially preferred when the concrete element 20 is exposed to strong pressure loads. For example, this way the earthquake protection of bridge pylons can be improved.

In order to be able to provide optimal environmental conditions for the hardening of the concrete, in a preferred embodiment, the rising tower is surrounded outside and/or inside with a tubular shell (e.g. a shell made out of plastic foil). This shell can be unrolled from a roll during the extrusion of the tower and pulled with it upwards. By such a shell, the air humidity can be kept over several days in the area between 90 and 100%. Eventually a heater/air humidifier can be used in the interior of the tower. The shell can be simply removed later.

It is obvious, that the concrete element 20 can also have other cross sections and before all can also different cross section by height.

On FIG. 12 a concrete element with a different cross section is shown. A ring-shaped casing element acts as inner casing 12. The outer casing 11 has the form of a polygon (in the shown example an octagon). Through the radial shifting of the individual casing walls of the outer casing 11, the thickness of the concrete element can be varied during the extrusion.

Especially preferred is an outer and/or inner casing of a large number of single, elongated stripes, which are arranged side by side in the shape of a polygon. The diameter of the casing can be increased by inserting more stripes. A reduction is possible in that one removes stripes.

In the FIGS. 13A and 13B details of a further embodiment are shown. On FIG. 13A it is to be noticed, that a foundation is provided in the ground. A foundation step 14 of concrete will be cast on this foundation. A door 60 can be provided in this foundation step, which allows an inner entry. Either can now the inner and outer casings be mounted on the foundation step as shown in FIG. 1A or a further casing 61 can be cast as integral part of the foundation step 14. This latest version is shown on FIG. 13A and FIG. 13B. The foundation step 12 has a height HS and the inner concrete casing 61 has a height HI. The outer casing 11 is indicated on FIG. 13A only with lines. Between the outer casing 11 and the inner casing 61 an interspace 16 is given, which will be filled with concrete from several places in the bottom. In the foundation 13 and foundation step 14 different anchors 19 or Monier iron rods are provided.

In the FIGS. 14A and 14B details of an outer casing 11 are shown. The outer casing comprises three cross segments, which each cover 120 degrees. The three elements are connected by means of flanges 63 and then form a cylindrical inner space with a diameter Da. In the shown example, inlets 15 for connecting the pumps are provided in three places. In order for the casing to be lifted, hooks or ears can be fitted for example.

In the FIGS. 15A to 15C details of a further method according to the invention are shown. In FIG. 15A a construction phase is shown, according to which the foundation step 14 together with the concrete inner casing 61 is being produced. In the foundation step 14, a door opening 60 is provided. Now an outer casing (for example the one shown in FIG. 14A) is mounted and concrete will be introduced in the interspace 16 from a silo 64 by pumps 17 through inlets 15. The concrete element rises upwards, as shown in FIG. 15B, and thus carries the attachment 24. Steel scaffold 36 with lifting equipment and the like are fitted on the attachment. In the inside of the tower electro-optical means 26 (as already described) are placed, so that, during the rising of the tower, the vertical alignment can be checked and corrected.

On FIG. 15C, a few finishing steps are described. A cable channel 23 is laid in the foundation, so that the tower can be conducted with a cable 66. In the inside of the tower, an elevator cabin 65 or a lifting platform is provided. On the attachment 24, measuring constructions 67 for measuring the wind speed and weather conditions as well as the gondola 50 of a wind turbine are mounted.





 
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