DE29922468U1 - Device for the production of prestressed concrete parts - Google Patents

Description

Dipl.-Chem. Dr. Steffen ANDRAE

Dipl.-Phys. Dieter FLACH

Dipl.-Ing. Dietmar HAUG

Dipl.-Chem. Dr. Richard KNEISSL

Dipl.-Ing., Dipl.-Wirtsch.-Ing. Friedrich BAUER

Dipl.-Phys. Dr. Martin FRIESE

Balanstrasse 55

81541 Munich

Our reference number: 3028A

Applicant: NOE-SCHALTECHNIK GEORG MEYER-KELLER

GMBH & CO.
Kuntzestrasse 72
D-73079 Suessen

Device for producing prestressed concrete parts

The invention relates to a device for producing prestressed concrete parts, with an elongated base frame which has a plurality of parallel rails running transversely to the longitudinal direction of the base frame, on which supports are mounted which can be moved along the rails and to which a formwork is attached, as well as with two tensioning devices spaced apart from one another in the longitudinal direction of the base frame for tensioning prestressing strands to be arranged in the prestressed concrete parts, and with two parallel pressure beams running in the longitudinal direction of the base frame, with the ends of which the tensioning devices are in contact in order to support themselves thereon when tensioning the prestressing strands.

Such a device for the production of prestressed concrete parts is known from the utility model 7431775. In this device, the formwork consists of formwork parts extending over the entire length of the device, which are permanently

are attached to the supports and therefore only allow the production of a specific shape of prestressed concrete parts. The formwork parts can be moved transversely together with the supports, so that the dimensions of the prestressed concrete parts can be changed transversely. However, the basic shape of the prestressed concrete parts and their height remain the same. Furthermore, the pressure beams extend continuously over the entire length of the device. In the case of prestressed concrete parts that are shorter than the total length of the device, the prestressing strands are inevitably considerably longer than the prestressed concrete parts, because the distance between the prestressing devices is determined by the length of the pressure beams. In the case of prestressed concrete parts that are shorter than the device, excess lengths of prestressing strands therefore arise.

The object of the invention is to further develop the device for producing prestressed concrete parts of the type mentioned at the outset in such a way that the prestressed concrete parts can be produced in different shapes and dimensions in the longitudinal and transverse direction, whereby the prestressing strand consumption for prestressed concrete parts which are shorter than the device is reduced compared to the prestressing strand consumption when producing prestressed concrete parts of corresponding length using the previously known device.

The object of the invention is achieved in that the formwork consists of individual formwork elements detachably attached to the supports and the pressure beams are each divided into at least two pressure beam sections arranged one behind the other lengthwise and abutting one another with their opposite ends, which can each be moved sideways on the rails together with the supports arranged between them and the formwork elements on the carriages carrying the supports and the respective pressure beam section.

The device according to the invention allows the use of formwork elements of different heights and lengths, whereby the

Formwork elements can be lined up lengthwise and increased in height. Bracket formwork parts can be arranged between two formwork elements arranged lengthwise in succession in order to form brackets directly onto the prestressed concrete parts. Formwork parts for forming recesses in the prestressed concrete parts can also be provided between two formwork elements arranged lengthwise in succession. The division of the pressure beams into at least two pressure beam sections arranged lengthwise one behind the other and abutting at their opposite ends enables the production of prestressed concrete parts whose length corresponds either to the length of a pressure beam section or to the total length of the abutting pressure beam sections, whereby the distance between the tensioning devices can be set to the length of a pressure beam section or to the partial length or the total length of several abutting pressure beams, so that the length of the prestressing strands can be adapted to the length of the prestressed concrete parts to be produced. This results in a reduced consumption of prestressing strands when producing prestressed concrete elements whose length is shorter than the length of the device.

Advantageous developments of the invention are the subject of the subclaims.

An embodiment of the invention is shown in the drawings and is described in more detail below. It shows

Figure 1 is a schematic side view of the device according to the invention for producing prestressed concrete parts, wherein the pressure beams are divided into three abutting pressure beam sections;

Figure 2 is a plan view of the device shown in Figure 1, but with the difference that only two of the pressure beam sections abut each other and the tensioning device arranged on the right side in Figure 1

device is offset to the right-hand end of the two abutting pressure beam sections in order to be able to produce a shorter prestressed concrete part than with the version of the device shown in Figure 1;

Figure 3 is a plan view of the formwork elements joined together in the longitudinal direction, with a bracket formwork module provided on one side of the formwork for the purpose of forming a bracket on the prestressed concrete part;

Figure 4 is an end view of the device shown in Figure 1, showing two different possible cross-sectional shapes of prestressed concrete parts as well as raised formwork elements of different heights;

Figure 5 shows a detail of the device shown in Figure 1, wherein a clamping holder for the releasable fastening of a formwork element to the support and a clamping device for the stepless clamping of a carriage carrying the respective pressure beam section and the support to a transverse rail are shown schematically;

Figure 6 is a rear view of the clamping device shown in Figure 5;

Figure 7 is a plan view of the clamp holder shown in Figure 5, with the release position of the pivoting arm shown in dashed lines, and

Figure 8 shows an alternative clamping device with a hydraulic cylinder for hydraulic actuation of the wedge of the clamping device.

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As shown in Figures 1 and 2, a device for producing prestressed concrete parts according to the invention comprises an elongated base frame 1 which consists of three parallel beams 2 running in the longitudinal direction and a plurality of parallel rails 3 running transversely to the longitudinal direction of the base frame 1 and arranged at equal intervals in the longitudinal direction on the beams 2. As can be seen in particular in Figure

I, the device in the embodiment shown has, for example, three abutting pressure beam sections 4, 5 and 6 on each side, which abut one another with their opposite ends, which are plate-shaped. The pressure beam sections 4, 5 and 6 together form a pressure beam 7 which extends between two hydraulic tensioning devices 8 and 9, each of which is arranged at one end of the base frame 1. Overall, the device has two parallel pressure beams 7 running in the longitudinal direction of the base frame, as can be seen particularly in Figure 2. A formwork 10 is arranged between the two pressure beams 7, with which a prestressed concrete part is produced. A large number of prestressing strands 11 extend between the two tensioning devices 8 and 9, which run within the formwork 10 and consequently within the prestressed concrete part to be produced. In operation, the two tensioning devices 8 and 9 subject the prestressing strands

II a predetermined tensile stress, whereby the tensioning devices 8, 9 support each other via the pressure beams 7, with the ends of which their hydraulic cylinders 8a, 9a are in contact.

Each rail 3 consists of a pair of parallel double-T beams 3A, 3B (see Figure 6) which are arranged at a distance from one another. On each pair of double-T beams 3A, 3B, a slide 12 in the form of a plate is arranged so as to be displaceable in the longitudinal direction of the beams 3A, 3B, which carries a support 13 to which a formwork element 14 of the formwork 10 can be clamped. The slide 12 also supports a respective pressure beam section of the

corresponding pressure beam 7. As can be seen from Figure 5, the support 13 is arranged between the formwork element 14 clamped to it and the respective pressure beam section of the corresponding pressure beam 7 on the carriage 12. Due to the joint arrangement of the support 13 and the respective pressure beam section of the pressure beam 7, the respective pressure beam section of the pressure beam 7 can be moved sideways together with the supports 13.

As shown in Figure 2, the two pressure beam sections 6 together with the supports 13, which are connected to the pressure beam sections 6 via the respective slides 12, are pushed outwards sideways, which makes it possible to move the clamping device 9 by means of a crane from the location shown in Figure 1 to the location shown in Figure 2, where it is located between the two pressure beam sections 6. The position of the clamping device 9 shown in Figure 1 is shown in dashed lines in Figure 2.

Since the pressure beam sections 4 and/or the pressure beam sections 5 can also be moved laterally together with the respective supports connected via the slides, and both the tensioning device 9 and the tensioning device 8 can be moved to the ends of the respective pressure beam sections 4, 5 and 6, different partial lengths of prestressed concrete parts can alternatively be produced on one and the same device. While in the embodiment in Figure 1 all pressure beam sections 4, 5 and 6 are arranged abutting one another, in the embodiment in Figure 2 only the pressure beam sections 4 and 5 are arranged abutting one another. Other combinations of abutting pressure beam sections are possible, such as the pressure beam sections 5 and 6, in which case the pressure beam sections 4 would be pushed outwards laterally. In this case the tensioning device 8 would be arranged at the left end of the pressure beam sections 5 in Figure 2. It is also possible to use the compression beam sections 4, 5 or 6 individually if the prestressed concrete parts to be produced are in the

Length either correspond to pressure beam sections 4 or 5 or 6. It should be noted that the pressure beam sections 4, 5 and 6 shown in Figures 1 and 2 are only an example of the different lengths and the number of pressure beam sections. More or fewer pressure beam sections with other partial lengths than those shown can also be used.

Figures 5 and 7 show a clamp holder for releasably holding the formwork element 14 on the support 13 in more detail. The clamp holder 16 has a threaded spindle 18 which is rotatably mounted in a bearing block 17 and with the thread of which a threaded sleeve 19 is engaged, which is formed in one piece with a pivoting arm 20. The bearing block 17 is fastened to the support 13 and aligned so that the axis of rotation of the threaded spindle 18 runs vertically and next to a side surface of the support 13. At the upper end of the threaded spindle 18 there is a hexagon nut 21 which is connected to the threaded spindle 18 in a rotationally fixed manner. The hexagon nut 21 can be turned using an open-end wrench or a motor-driven screwing tool, whereby the threaded spindle 18 also rotates when the hexagon nut 21 is turned. The boom 20 has a boom arm 22 which extends downwards at an angle of 45° and at the free end of which there is a clamping jaw 23 which is in contact with a rear upper side surface of a square central tube 24 which extends across the width of the formwork element 14 and forms an integral part of the formwork element 14 when the formwork element 14 is clamped to the support 13, as can be seen in Figures 5 and 7. In the clamped state, the lower edge of the formwork element 14 rests on an arm 25 which projects away from the support 13. The cantilever arm 25 is supported by ribs 26.

As can be seen in Figure 5, the square central tube 24 is arranged so that its side surfaces each form an angle of 4 5° with a central axis passing through the formwork element 14.

plane which is parallel to the plane of the formwork surface 2 7 of the formwork element 14.

By turning the threaded spindle 18 clockwise via the hexagon nut 21, the threaded sleeve 19 is moved upwards, whereby the clamping jaw 23 is lifted off the rear upper side surface of the square central tube 24. If the boom 20 has been moved upwards by turning the threaded spindle 18 so far that the free end of the boom arm 22 is above the upper edge of the square central tube 24, the boom 20 can pivot into the release position shown in dashed lines in Figure 7 using static friction. The formwork element 14 can then be lifted off the cantilever arm 25 and, if necessary, replaced with another formwork element with different dimensions.

The formwork element 14 is attached to the support 13 in the reverse order. First, the formwork element 14 is placed with its lower edge on the cantilever arm 25. By turning the threaded spindle 18 anti-clockwise via the hexagon nut 21, the boom 20 pivots, using static friction, from the release position shown in dashed lines in Fig. 7 by approx. 90° until it stops on the front edge of the bearing block 17. By turning the threaded spindle 18 further anti-clockwise, the threaded sleeve 19 moves downwards with the boom 20 until the clamping jaw 23 engages behind the square central tube 24. Then, by further turning the threaded spindle 18 anti-clockwise, the clamping jaw 23 is pressed against the rear upper outer surface of the square central tube 24, whereby the formwork element 14 is held firmly to the support 13 and the cantilever arm 25.

The distance of the square central tube 24 from the lower edge of the formwork element 14 depends on the height of the formwork element 14, because the greater the height of the formwork element 14, the greater the distance of the square central tube 24 from

the lower edge of the respective formwork element 14. The range of height adjustment of the boom 20 predetermined by the length of the threaded spindle 18 guarantees that the boom 20 can be brought into contact with the square central tube 24 of all common formwork elements which have a height between 450 and 1050 mm in order to clamp the respective formwork element to the support 13.

As can be seen from Figures 5 and 6, the carriage 12 with the support 13 arranged thereon and the respective pressure beam section of the pressure beam 7, including the formwork element 14 clamped to the support 13, can be clamped to the double-T beams 3A, 3B of the rail 3 by means of a clamping device 28. The clamping device 28 has a C-shaped plate 2 9, the upper leg 29A of which is fastened to the bracket 15 by means of a screw 3 0 shown in Figure 8 and a nut 31. Between the inner edge of the upper leg 2 9A of the C-shaped plate 2 9 and the top of the carriage 12 there is a gap into which a wedge 32 can be inserted. The wedge 32 is guided in two opposite slots in the walls of the bracket 15. The C-shaped plate 29 has a lower leg 29B on which there is a clamping jaw 33 which can be pressed against the underside of the upper, inner web parts of the double-T beams 3A and 3B. As can be seen from Figure 6, the two double-T beams 3A and 3B are located at a distance from one another and the middle section of the C-shaped plate 29 connecting the upper and lower legs 29A and 29B projects through the gap between the two double-T beams 3A and 3B. By driving the wedge 32 into the space provided between the upper leg 2 9A and the slide 12 by striking the wedge 32 with a hammer, the clamping jaw 33 is pressed against the underside of the upper inner flange parts of the double-T beams 3A and 3B, whereby the slide 12 is held on the double-T beams 3A and 3B of the rail 3 by frictional engagement between the clamping jaw 3 3 and the underside of the upper inner flange parts of the double-T beams 3A and 3B in the respective transverse position

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carriage is clamped relative to the rails 3.

After the wedge 32 has been loosened, the carriage 12 with the parts arranged on it can be moved transversely on the rail 3. The transverse displacement of the carriage 12 on the rail 3 enables the distance between two formwork elements 14 lying opposite one another in the transverse direction to be adjusted. Furthermore, the transverse displacement of the carriage 12 on the rail 3 enables the compression beam sections lying opposite one another in the transverse direction, together with the supports 13 assigned to them, to be moved apart to the ends of the rail 3, so that, as shown in Figure 2, for example, the tensioning device 9 can be moved between the compression beam sections if shorter prestressed concrete beams are to be produced.

An alternative clamping device 28' is shown in Figure 8. The alternative clamping device 28' differs from the clamping device shown in Figures 5 and 6 essentially in that the wedge 32' can be actuated by means of a double-acting hydraulic cylinder 34 which is attached to the bracket 15 via a holder 34'. Since two opposing clamping devices are provided on each rail for locking the two slides assigned to each rail, a number of wedges corresponding to the number of clamping devices is provided, each of which is assigned a hydraulic cylinder. The hydraulic cylinders 34 can be actuated jointly, which means that the release and locking of the clamping devices can be accelerated considerably compared to manual individual actuation of the wedges.

As shown in Figure 4, a horizontally running formwork floor 35 extends between two opposing formwork elements 14, which is constructed from a plurality of beams 3 6 running parallel to the rails 3 and on a formwork skin 3 7 lying thereon. The beams 3 6 have a rectangular cross-section and lie on a series of double

T-beams 3 8 which are arranged parallel to one another in the longitudinal direction of the base frame 1. The double T-beams 38 rest on the rails 3. The beams 3 6 can be arranged on the double T-beams 3 8 upright, as can be seen in the left part of Figure 4, or on the wide side, as can be seen in the right part of Figure 4. The height of the formwork floor 35 can be set to two different levels by the selected position of the beams 3 6, as can be seen in Figure 4.

Figure 4 shows the arrangement of the prestressing strands 11 in two different prestressed concrete parts. In the prestressed concrete part half shown on the left of a plane of symmetry in Figure 4, the prestressing strands 11 are arranged symmetrically to a plane passing through the center axis of the pressure beams 7, with the height of the formwork floor being set to the upper level by placing the beams 3 6 upright. When tensioning the prestressing strands 11 of the prestressed concrete part on the left in Figure 4, no torques are generated on the pressure beams 7 by the compressive forces introduced into the pressure beams 7 by the tensioning devices.

In the prestressed concrete half shown to the right of the plane of symmetry in Figure 4, a large number of prestressing strands 11 are arranged one above the other in a few rows. The prestressing forces acting on the prestressing strands 11 of the prestressed concrete part on the right in Figure 4 result in a total force that lies in a plane that is slightly above the plane that passes through the center line of the pressure beams 7. The distance between these two planes is relatively small because the formwork floor in the prestressed concrete part on the right in Figure 4 is lowered by the beams 3 6 being placed on their broad side. The small distance between the plane in which the total force acts on the prestressing strands 11 in the prestressed concrete part on the right in Figure 4 from the plane that passes through the center line of the pressure beams 7 produces only a small moment on the pressure beams 7 and accordingly only small vertical forces at the ends of the pressure beams, and these vertical forces are transmitted to the

Subframe 1 is introduced. Therefore, there is no need for complex anchoring of the subframe to the ground.

Figure 4 also shows the possibility of extending the formwork elements 14 by a further formwork element 14', wherein the further formwork element 14' can be clamped to the formwork element 14 arranged underneath in a conventional manner.

Fig. 3 shows an example of a formwork for a prestressed concrete part, in which a formwork module 40 for a bracket, which is molded directly onto the prestressed concrete part, or formwork elements 41 for a recess in the prestressed concrete part, are used on one side of the formwork.

In the example shown, only a so-called single formwork is used. However, a twin formwork can also be used as an alternative to the single formwork. In any case, the formwork elements can have different heights and lengths and can be exchanged for formwork elements of other dimensions. The lateral movement of the formwork elements can be manual, hydraulic, mechanical or electromechanical. In any case, two pressure beam sections opposite each other in the transverse direction are moved laterally.

If necessary, the pressure beams can be replaced by other pressure beams that meet higher strength requirements.

The device according to the invention enables the production of prestressed concrete columns with cross-sections that are significantly smaller than the cross-sections of previously known concrete columns.

Claims (10)

1. Device for producing prestressed concrete parts, with an elongated base frame ( 1 ) which has a plurality of parallel rails ( 3 , 3 A, 3 B) running transversely to the longitudinal direction of the base frame ( 1 ), on which supports ( 13 ) which can be moved along the rails and to which a formwork ( 10 ) is fastened are mounted, and with two tensioning devices ( 8 , 9 ) spaced apart from one another in the longitudinal direction of the base frame ( 1 ) for tensioning prestressing strands ( 11 ) to be arranged in the prestressed concrete parts, and with two parallel pressure beams running in the longitudinal direction of the base frame ( 1 ). ( 7 ), with the ends of which the tensioning devices ( 8 , 9 ) are in contact in order to support themselves thereon when tensioning the tensioning strands ( 11 ), characterized in that the formwork ( 10 ) consists of individual formwork elements ( 14 ) detachably fastened to the supports ( 13 ) and the pressure beams ( 7 ) are each divided into at least two pressure beam sections ( 4 , 5 , 6 ) arranged one behind the other lengthwise and abutting one another with their opposite ends, which can each be moved sideways on the rails ( 3 , 3 A, 3 B) together with the supports ( 13 ) arranged between them and the formwork elements ( 14 ) on these supports ( 13 ) and the respective pressure beam section ( 4 , 5 , 6 ) carrying carriages ( 12 ). 2. Device according to claim 1, characterized in that each carriage ( 12 ) can be continuously clamped to the respective rail ( 3 , 3A , 3B ) by means of a clamping device ( 28 ) fastened to it. 3. Device according to claim 2, characterized in that each clamping device ( 28 ) has a C-shaped plate ( 29 ) which has a lower leg ( 29B ) and an upper leg ( 29A ), a clamping jaw ( 33 ) fastened to the lower leg ( 29B ) and which can be pressed against an underside of the respective rail ( 3 , 3A , 3B ), and a wedge ( 32 ) which can be displaced transversely to the plate ( 29 ) and which can be displaced between the upper leg ( 29A ) of the plate ( 29 ) and the upper side of the carriage ( 12 ). 4. Device according to claim 3, characterized in that the wedges ( 32 ') of the clamping devices ( 28 ') are displaceable by means of hydraulic cylinders ( 34 ) relative to the respective plates ( 29 ) for releasing and tightening the clamping devices ( 28 '). 5. Device according to claim 1 or 2, characterized in that the formwork elements ( 14 ) can each be releasably secured to the supports ( 13 ) by means of a clamp holder ( 16 ) provided on each support ( 13 ). 6. Device according to claim 5, characterized in that each clamp holder ( 16 ) has a boom ( 20 ) which is height-adjustable on the respective support ( 13 ) and pivotable about an upright axis of rotation and which can be pressed against a contact surface located on the respective formwork element ( 14 ), and that a cantilever arm ( 25 ) is arranged on each support ( 13 ), on which the respective formwork element ( 14 ) can be placed, wherein by pressing the boom ( 20 ) against the contact surface of the formwork element ( 14 ), the formwork element ( 14 ) is clamped to the cantilever arm ( 25 ) and to the support ( 13 ). 7. Device according to claim 6, characterized in that the axis of rotation of the clamp holder ( 16 ) is formed by a spindle ( 18 ) which is rotatably mounted on the support ( 13 ) and has a thread with which a threaded sleeve ( 19 ) is engaged, which is formed in one piece with the boom ( 20 ). 8. Device according to claim 6 or 7, characterized in that the contact surface of the formwork element ( 14 ) is an outer wall of a square central tube ( 24 ) which runs on the rear side of the formwork element ( 14 ). 9. Device according to one of the preceding claims, characterized in that at least one clamping device ( 8 , 9 ) is movable relative to the base frame ( 1 ) in such a way that it can be arranged at a location between the longitudinally spaced ends of the base frame ( 1 ), the distance of which from the other clamping device ( 8 , 9 ) is determined by the respective total length of the pressure beams ( 7 ). 10. Device according to one of the preceding claims, characterized in that the formwork ( 10 ) has a formwork floor ( 35 ) which is supported on the rails ( 3 ) and runs below a horizontal plane passing through the central axes of the pressure beams ( 7 ).