EP2239119A2 - Mobile tensioning bed for prestressed concrete products - Google Patents

Abstract

The bed (1) has two abutment plates (7, 8) arranged opposite to each other, and abutment profiles (6) arranged between the abutment plates. Prestressed reinforcement cords accommodated in a cross section of prestressed reinforcement, where the cords are arranged in a table form. The profiles press the plates against each other by a clamping device (4) i.e. piston-hydraulic cylinder device. Reinforcement elements are made of strands or wires or rods, and hydraulic cylinders are fastened to an axis of a pressure pipe.

Description

The invention relates to a mobile fitted bed for precast concrete elements with prestressed reinforcement according to the preamble of claim 1.

It is known to produce prefabricated concrete elements in the precast plant characterized in that the precast concrete element is made on the surface of a circulation pallet, wherein in a known manner, the circulation pallet has a clamping frame to receive the prestressed reinforcing strands under pretension in the clamping frame. On the surface of this circulation pallet, the ready-mixed concrete is then poured, so that the prestressed reinforcing strands are taken up in the ready-mixed concrete and bias the finished concrete part after curing of the ready-mixed concrete.

However, the arrangement of a clamping frame on the circulation pallet has the disadvantage that high pressure forces must be absorbed by the clamping frame. There are therefore used front and rear large-sized profile beam, which serve as an abutment for there to be absorbed and to be held under prestress reinforcement strands. The reinforcement strands are pulled through the abutment beams with a suitable pulling device and tensioned to a tensile force of z. B. 180 kgN per strand to produce.

This has the disadvantage that the Litzendurchführung is asymmetrical in the clamping frame in the vertical direction. The clamping frame is indeed placed on the surface of the circulation pallet. However, the reinforcement strands must be placed in the lower foot area of the profile beams in order to be embedded in the material of the ready-mixed concrete.

Because of this (relative to a vertical) decentralized - outside the center of gravity of the profile beam - acting tensile forces profile beams must be suitably reinforced in order to reduce the occurring buckling and absorb bending forces. As a result, such a tenter frame weighs up to 15 t with a size of approximately 4 x 16 m.

The invention is therefore the object of developing a clamping device for circulating pallets of the type mentioned so that it is designed to be much smaller, less expensive to produce and is freely convertible.

To solve the problem, the invention is characterized by the technical teaching of claim 1.

An essential feature of the invention is that instead of the known tenter, which was firmly connected to the circulation pallet, a mobile fitted bed is used, which is simply placed on the surface of the circulation pallet.

This creates a inherently stable mobile (ie easy to implement) fitted bed, which is no longer dependent on the connection with the circulation pallet, because it is freely convertible from one circulation pallet to the other, because all acting stresses are absorbed in the mobile bed itself ,

Instead of a fixedly connected to the circulation pallet stretcher, the invention now proposes to use a self-supporting, independent of the clamping frame, and inherently stiff clamping bed. This is therefore easy to transport and no longer rely on the attachment with the circulation pallet.

In a preferred embodiment of the present invention, it is provided that the clamping bed according to the invention consists of two opposing abutment plates, between which one or more abutment profiles are arranged, which press the two abutment plates against each other by means of a clamping device.

In the lower part of each abutment plate one or more strand-like or wire-like or rod-like reinforcing elements are arranged, which are assigned to the respective abutment plate respectively associated tension elements, which also consist of strands, wires or rod-shaped elements.

With the given technical teaching, the advantage is now achieved for the first time that the abutment plates with the intermediate abutment profiles are statically balanced in itself, because the underlying wire-like or strand-like reinforcing elements are now according to the invention opposite upper tension elements, which are connected to the abutment plates 7, 8 and which take up the same train as comparatively the lower reinforcing elements.

Thus, the reinforcing elements - as recognized as disadvantageous in the prior art - no longer claim the abutment plates on bending or tilting, because this bending or tilting are now opposite the overhead tension elements that transmit the same train as comparatively he acts on the lower reinforcing elements ,

The actual tensile force is thus transmitted between the abutment plates via the abutment profiles arranged centrally therebetween, which press with a tensioning device against the respective abutment plate.

For the formation of the tensioning device, there are various embodiments, all of which should be included as essential to the invention of the present invention.

In a first embodiment, it is provided that at a front, free end of an abutment profile, a clamping device is arranged, which presses with one side on the end face of the abutment profile and with the other end face on the abutment plate.

Such a clamping device is preferably designed as a piston hydraulic cylinder device.

Instead of such a piston-cylinder device, however, other clamping devices can be used, in particular mechanical or electromotive tensioning devices.

As a mechanical tensioning device, there are mechanically or motor-operated spindle devices.

Similarly, eccentric tensioning devices can be used, which are operated by hand or by motor or hydraulic.

In a further embodiment, it can be provided that the pulling device acts on the abutment plate from the outside and pulls the abutment plate away from the abutment profile.

For this embodiment, it is then provided that in the resulting distance between the end face of the abutment profile and the inside of the abutment plate a suitable wedge or other compensation element is taken to hold the two abutment plates by interposition of the abutment profile on compressive force.

It is important in all embodiments that the respective table near the top of the circulation pallet arranged reinforcing elements which are poured into the precast concrete, now according to the invention opposite to the respective abutment plate, a tension element is assigned, which transmits the same tensile forces as the reinforcing elements, which are poured into the concrete ,

Thus, centric pressure forces are always generated on the abutment plates, without causing undesirable bending or tilting of the abutment plates.

While the tensile forces are transmitted via the upper tension elements and the lower reinforcement elements, the pressure forces are transmitted via the intermediate abutment profiles.

Thus, it is now possible for the first time to form such a mattress mobile (easily transportable), because it is - as stated above - statically balanced in itself and can be transported as a package from the surface of any circulation pallet to another circulation pallet and placed there and be involved in the work process.

Likewise, this results in the advantage that several clamping beds can be arranged next to each other in a modular manner, wherein the one clamping bed can look quite different than the other, adjacent clamping bed. This results in a variety of alternative options, if z. B. the leadership of the train and the reinforcing elements deviates in the one clamping bed of the leadership of the tension and reinforcing elements in the adjacent clamping bed.

This results for the first time the possibility that one can bias ribbed plates or individual carriers with arranged at different heights reinforcing elements, which was previously possible only with great effort in the known tenter.

• zwei Stahlplatten als Widerlager am jeweiligen Ende der Einheit
• einem Druckrohr zwischen den beiden Stahlplatten
• einem Hydraulikzylinder in der Achse des Druckrohrs befestigt an einer der Stahlplatten

Instead of a large tenter, smaller units are used. These mobile clamping units are composed of the following components:

• two steel plates as an abutment at each end of the unit
• a pressure tube between the two steel plates
• a hydraulic cylinder in the axis of the pressure tube attached to one of the steel plates

The steel plates form the abutment yoke for receiving the strands with their anchors. Therein, the openings for the layered mounting of the permanent and temporary anchor boxes are attached. The steel plates are standing on the formwork floor and thus determine the altitude of the exciting strands.

The later einzubetonierenden in the component strands are arranged in the lower region of the steel plate near the formwork base according to their subsequent axial position. Supplementary so-called auxiliary strands in the upper part of the steel plates are required. These hold the balance of forces around the axis of the pressure tube. These strands can be used over and over again, so can be used for monolayers in PE sheath. Its associated anchoring is permanent and always remains fixed to the steel plate.

The two steel plates and the pressure tube with the intermediate cylinder form a stable unit that can move as a whole, settle on the formwork and also lift off. Pipe, cylinder and steel plates are bolted together. In addition, the upper auxiliary strands always remain fixed to the unit. This applies both in the tensioned and in the relaxed state.

The einzubetonierenden strands are fixed in position on the steel plates, aligned and slightly tense. By loading the cylinder, all strands (bottom + top) are tensioned evenly. The cylinder is fixed after clamping with a collar in the extended position. The unit with the tensioned strands can be placed as a whole construction on the formwork and aligned in this. The lower strands then come to lie within the cross section of the later component. After concreting the component, these strands are embedded in concrete. With the release of the cylinder all strands of the unit are relaxed. The clamping force of the lower strands passes over the component to be prestressed by bonding. This will pre-stress the component with the strands. By removing the anchor boxes on the steel plates, the entire clamping unit can be removed from the formwork and prepared for the next use.

Small mobile clamping units consist of a cast-out ø133mm steel pipe and the slightly larger units use two parallel laid steel pipes with a preferred ø133mg.

Due to the parallel arrangement of strand bundles in the lower and upper layers, these mobile tensioning units have the advantage that the strand bundles can be deflected at almost random points by spreading. With spacers, the parallel strand bundles are moved at discrete points from its parallel axis, and thus deflected accordingly. This creates a deflected Spannlitzenverlauf, which is then implemented as such in the component. The strands associated with the mobile tensioning bed are therefore also capable of taking up not only straight-line geometries. Thus, e.g. a carrier be biased trapezoidal according to its course of torque, thus optimally exploiting the clamping reinforcement, and optimally bias the carrier.

The leadership of the strand bundles at a defined distance from the central pressure tube in the tensioned state has the great advantage that the pressure tube can never buckle, as the off-center arranged tension strands stabilize the pressure tube as a corrective with the spacer elements. Thus, the pressure pipe can be designed to the absolute minimum in the dimensions (only for the transmission of compressive stresses from the prestressed strands).

Depending on the width of the component to be prestressed, several mobile tensioning units must be prepared accordingly and positioned next to one another on the control table. In this case, units can alternate with each other, so that straight tendons alternate with curved. Thus, then also a ribbed plate blank can be optimally biased, wherein in the ribs a curved tendon course and in the attached plates a straight tendon guide can be realized.

A mobile clamping unit for pre-tensioning 6 strands (Ap = 100mm2) weighs approx. 1.1 to total with cylinder and steel plates. For a plate with a Width of 2.70m, about 30 strands are needed. Thus, about five mobile clamping units are to be arranged next to each other with a total additional weight of 5.5 to. If fewer wires are needed, not so many mobile clamping units need to be used.

The cost of a mobile clamping unit with the cylinder is about 6,000.00 EUR. Compared to a possible tentering frame placed on the revolving table at a cost of about 100'000,00EUR, 30'000,00 EUR for five mobile units equivalent to the tenter frame are very economical. In addition, the mobile clamping units are characterized by the lower weight and greater flexibility in the application.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following, the invention will be explained in more detail with reference to drawings illustrating several execution paths. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Figur 1:

Draufsicht auf ein mobiles Spannbett in einer ersten Ausführungsform mit der Auflage auf eine Umlaufpalette

Figur 2:

Schnitt durch die Anordnung nach Figur 1

Figur 3:

die Anordnung nach Figur 1 und 2 in perspektivischer Seitenansicht von links

Figur 4:

die gleiche Darstellung in der perspektivischen Ansicht von rechts

Figur 5:

eine gegenüber Figur 3 und 4 erweiterte Ausführungsform eines mobilen Spannbettes

Figur 6:

die Draufsicht auf die Anordnung nach Figur 5

Figur 7:

eine Detaildarstellung einer Stirnseite der Anordnung nach Figur 6

Figur 8:

eine zweite Ausführungsform eines mobilen Spannbettes mit dazwischengeschalteten Spreizelementen

Figur 9:

die perspektivische Ansicht auf die Darstellung nach Figur 8

Figur 10:

die vergrößerte Seitenansicht der Anordnung nach Figur 8 und 9

Figur 11:

eine Draufsicht auf die Kombination verschiedener mobiler Spannbetten

Figur 12:

die Seitenansicht auf das mobile Spannbett, welches in Figur 11 verwendet wird

Figur 13:

die Seitenansicht auf die zweite Ausführung eines mobilen Spannbettes, welches ebenfalls in Figur 11 verwendet wird.

Show it:

FIG. 1:

Top view of a mobile fitted bed in a first embodiment with the support on a circulation pallet

FIG. 2:

Section through the arrangement after FIG. 1

FIG. 3:

the arrangement after FIG. 1 and 2 in a perspective side view from the left

FIG. 4:

the same representation in the perspective view from the right

FIG. 5:

one opposite FIG. 3 and 4 extended embodiment of a mobile fitted bed

FIG. 6:

the top view of the arrangement according to FIG. 5

FIG. 7:

a detailed representation of an end face of the arrangement according to FIG. 6

FIG. 8:

a second embodiment of a mobile tensioning bed with interspaced expansion elements

FIG. 9:

the perspective view of the representation after FIG. 8

FIG. 10:

the enlarged side view of the arrangement according to FIG. 8 and 9

FIG. 11:

a plan view of the combination of different mobile Spannbetten

FIG. 12:

the side view of the mobile fitted bed, which is in FIG. 11 is used

FIG. 13:

the side view of the second embodiment of a mobile clamping bed, which also in FIG. 11 is used.

In the FIGS. 1 and 2 a circulation pallet 2 is shown, which consists essentially of rollers 3, on which a stiffening support 11 is arranged, which in turn carries a steel plate 12.

The steel plate 12 is the table on which the hardenable concrete mass is applied, and in the later drawings, it is always assumed that the Concrete mass is processed into a concrete element 5, which is penetrated by under tensile force reinforcing elements 10.

Thus, a prestressed concrete element 5 is created, wherein the reinforcing elements 10 may preferably be formed as steel strands, wires or rods. The type of reinforcing elements can also be mixed. This means that different types of reinforcing elements (strands, wires and rods) can be used together or in combination with each other.

The reinforcing elements 10 are added to the left and right sides in associated abutment plates 7, 8, which are preferably formed as steel plates.

It is important that the tensile elements loaded on tensile reinforcement elements 10 opposite tension elements 9 are arranged, which preferably correspond in size and number of the reinforcing elements 10.

However, the invention is not limited thereto.

For example, if a number of 5 reinforcing elements 10 can be provided from steel strands, a smaller number of tension elements can be arranged in the upper level (in the plane of the tension elements 9), or these tension elements can also consist of other materials. For example, if the reinforcing elements 10 are formed of steel strands, the oppositely arranged tension elements 9 may consist of steel bars, wires or the like, or also of steel strands. The invention thus provides all possible embodiments, wherein it is important that over the upper tension elements 9, the same tensile forces are transmitted (in the sum), as about the lower reinforcing elements 10th

This leads to exactly centric tensile forces are introduced to the two opposite abutment plates 7, 8, and this is important that between the abutment plates 7, 8 are each arranged a number of abutment profiles 6 centrally.
Such a centric arrangement is preferred to ensure that the abutment plates 7, 8 are exactly under the same bias up and down and then attack the abutment profiles 6 centered on the abutment plates 7, 8, so as to achieve a balanced state of force.

However, the invention is not limited thereto.

In another embodiment, it may be provided that the end faces of the respective abutment profiles decentralized to the abutment plates 7, 8 and that this resulting tilting moment is compensated for the abutment plates by appropriate Zugkrafteinstellung to the upper tension members.

This means that it is not necessary for the solution that the tensile force on the upper tension elements is the same as the tensile force on the lower reinforcement elements. This also depends on the type and arrangement of the interposed abutment profiles.

For the sake of simplicity, however, it will be assumed in the following description of a central arrangement of the abutment profiles to the abutment plates, and it is further assumed that the tensile force on the upper tension members is equal to the tensile force on the lower reinforcing elements in the concrete part of the tensile force are embedded. However, the invention is not limited to this, as described above.

In a preferred embodiment of the present invention, the tensile force is applied to the upper tension members and also to the lower reinforcing elements 10 by a tensioning device 4, which consists in the preferred embodiment of a piston-cylinder assembly. Further details of this piston-cylinder arrangement are for example FIG. 7 refer to. There it can be seen that the piston-cylinder arrangement between two pressure plates 16, 17 is arranged, for example, the piston 14 presses on the left pressure plate 16 on the abutment plate 8, while the cylinder housing 15 presses on an associated pressure plate 17 on the end face of the abutment profile 6.

In the exemplary embodiments, the abutment profile 6 is preferably designed as a tubular profile. In order to transmit corresponding pressure forces, it is preferred if this tube profile is filled with a concrete or other load-transmitting mass.

However, the invention is not limited to the formation of a tube profile. It can be used all known profiles, such as. B. extruded or oval or rectangular or square profiles.

It is only important that this abutment profile 6 is able to absorb the relatively high compressive forces and distribute between the abutment plates 7, 8.

In the Figures 3 and 4 is in each case a spatial representation of the arrangement according to the FIGS. 1 and 2 shown omitting the circulation pallet 2.

It can be seen that a number of tension elements 9, which are formed in the embodiment shown as steel strands, a similar number of reinforcing elements 10 are opposite, which are also designed as steel strands and enforce the concrete element 5 under tensile force.

The FIG. 5 shows a larger mobile fitted bed according to the invention, where it can be seen that a number of abutment profiles 6 can be used with associated clamping devices 4, wherein the abutment profiles 6a, 6b occupy a mutual distance and each in the space between the upper tension members 9 and the lower Reinforcing elements 10 are arranged.

The FIG. 6 shows the same arrangement as FIG. 5 in the plan view, from which further details.

The FIG. 7 shows the enlarged end view of the arrangement according to the Figures 3 and 4 , and this figure has already been described above. From this representation it can be seen that acts on the upper tension elements 9, a tensile force 18 which is exactly the same as the tensile force 19, which acts on the lower reinforcing elements 10.

The two tensile forces 18, 19 are compensated by the pressure force 20, which acts on the longitudinal cross section of the abutment profiles 6.

It has already been pointed out above in the general description part that in the illustrated embodiment, although the tensile forces 19 are equal and the opposite counteracts a same pressure force 20. However, the invention is not limited thereto. Same tensile forces with the same opposite compressive force will only arise if the abutment profile 6 exactly concentric to the respective abutment plate 7, 8 presses.

If there is a decentralized attack of the abutment profile 6, different tensile forces 18, 19 can arise. It is important, however, that the abutment plates 7, 8 are always biased uniformly to avoid kinking or tilting. This leads to the desired success of the invention that you can transmit high forces namely with relatively small components and also achieved instead of a fixed clamping frame now a mobile fitted bed.

The FIGS. 8 to 10 show as a further embodiment, that it is not necessary to guide the tension elements 9 and the reinforcing elements 10 in parallel under tensile force. There it is shown that between the elements 9, 10 spreading elements 13 are arranged, which are arranged perpendicular to the longitudinal extension of the elements 9, 10. Thus, the reinforcing elements 10 can be adapted to the bending moment curve in the concrete element 5, which was previously not possible.

This makes it possible to create smaller concrete elements 5.

The FIG. 10 shows as a further modification that it is possible, with the elimination of the tensioning device 4, an externally applied to the respective abutment plate 7, 8 pulling device which exerts a train in the direction of arrow 21 on both the tension elements 9 and the reinforcing elements 10.

This can be z. B. be provided that a non-illustrated pulling device acts directly on the abutment plate 7 or 8 and this centric pulls in the direction of the longitudinal extent of the abutment profiles 6 in the direction of arrow 21.

With the embodiment of FIGS. 8 to 10 Thus, another type of mobile clamping bed 22 is created, because with the illustrated elements 9, 10 and a curved course in the concrete element to be produced 5 is achieved.

The Figures 11 and 12 now show the combination of the mobile clamping beds 1, 22, which lie next to each other in a modular manner and are arranged in parallel on the surface of a circulating pallet, not shown. FIG. 11 shows here that in each case a newly developed mobile clamping bed 1 is alternated with a polygonal clamping bed 22 and that a total of three straight trained clamping beds are arranged alternately with two polygonal clamping beds 22 together on the surface of a circulating pallet 2.

This results in the advantage that you can now now for the first time cranked beams, ribbed plates or the like can make, because the reinforcing elements 10 in the straight mobile clamping bed 1 are performed differently than the reinforcing elements 10 in the polygonal clamping beds 22 so that you different shaped carrier or Plates or ribbed plates with an arrangement according to FIG. 11 can make.

The Figures 12 and 13 show only schematized in the side view of a mobile fitted bed 1 according to the embodiments described above Figure 1 to 4 and further the polygonal clamping bed 22 according to the embodiments according to FIGS. 8 to 10 ,

drawing Legend

1

Fitted bed (mobile)

2

circulating pallet

3

roll

4

Clamping device a, b

5

concrete element

6

Abutment profile 6a, 6b

7

Abutment plate

8th

Abutment plate

9

tension element

10

reinforcing element

11

stiffening girder

12

steel plate

13

spreader

14

piston

15

cylinder housing

16

printing plate

17

printing plate

18

traction

19

traction

20

thrust

21

arrow

22

Fitted bed (mobile)

Claims (16)

Prestressed bed for the production of precast concrete elements with prestressed reinforcement, in the cross-section of which a number of prestressed reinforcing strands are arranged, arranged on a switch table, characterized in that the fitted bed (1) is independent of its attachment to the switch table or a circulation pallet (2 ) is inherently stable and easy to transport. Fitted bed according to claim 1, characterized in that the clamping bed (1) consists of two opposing abutment plates (7, 8), between which one or more abutment profiles (6, 6a, 6b) are arranged, which by means of a clamping device (4, 4a, 4b) press the two abutment plates (7, 8) against each other. Fitted bed according to claim 1 or 2, characterized in that in the lower part of each abutment plate (7, 8) one or more reinforcing elements (10) are arranged, which opposite to the respective abutment plate (7, 8) each tension elements (9) are assigned. Fitted bed according to at least one of the preceding claims, characterized in that the reinforcing elements (10) optionally consist of strands or wires or rods or a combination of these elements. Fitted bed according to at least one of the preceding claims, characterized in that the tension elements (9) consist of strands or wires or rods or a combination of these elements. Fitted bed according to at least one of the preceding claims, characterized in that the abutment plates (7, 8) with the intermediate abutment profiles (6, 6a, 6b) are statically balanced in itself. Fitted bed according to at least one of the preceding claims, characterized in that the underlying reinforcement elements (10) are upper tension elements (9) opposite, which are connected to the abutment plates (7, 8) and which receive the same train, as compared to the lower Reinforcement elements (10). Fitted bed according to at least one of the preceding "claims, characterized in that at a front, free end of an abutment profile (6, 6a, 6b), a clamping device (4, 4a, 4b) is arranged, with the one side on the front side of the Abutment profile (6, 6a, 6b) and with the other end face on the abutment plate (7, 8) presses. Fitted bed according to at least one of the preceding claims, characterized in that the tensioning device (4, 4a, 4b) is designed as a piston hydraulic cylinder device. Fitted bed according to at least one of the preceding claims, characterized in that a pulling device acts on the abutment plate (7, 8) from the outside and pulls the abutment plate away from the abutment profile (6, 6a, 6b). A tensioning bed according to at least one of the preceding claims, characterized in that the reinforcing elements (10) which are cast in the prefabricated concrete part and are adjacent to the top of the circulating pallet (2) are opposite to the respective abutment plate (7, 8) a tension element (9 ) is assigned, which transmits the same tensile forces as the reinforcing elements (10) which are cast in the concrete (5). Fitted bed according to at least one of the preceding claims, characterized in that the tensile forces on the upper tension elements (9) and the lower reinforcing elements (10) are transmitted, and that the compressive forces on the intermediate abutment profiles (6, 6a, 6b) are transmitted , Fitted bed according to at least one of the preceding claims, characterized in that a plurality of clamping beds (1, 22) are arranged side by side in a modular fashion on a switch table or a circulation pallet (2). Fitted bed according to at least one of the preceding claims, characterized in that it consists of the following components: - Two steel plates (12) as an abutment at each end of the unit a pressure tube between the two steel plates (12) - A hydraulic cylinder (14, 15) in the axis of the pressure tube attached to one of the steel plates Fitted bed according to claim 14, characterized in that the steel plates (12) form the abutment yoke for receiving the strands with their anchors and that therein the openings for the layers moderate mounting of the permanent and temporary anchor boxes are mounted, wherein the steel plates (12) stand the shuttering floor and thus determine the altitude of the exciting strands. Fitted bed according to claim 15, characterized in that between the tension and reinforcement elements (9, 10) spreading elements (13) are arranged, which are arranged perpendicular to the longitudinal extent of the tension and reinforcement elements (9, 10).

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