CA1100737A - Method and arrangement for the manufacture of pre- cast plate-like concrete elements on the building site - Google Patents

Abstract

Abstract of the Disclosure The invention relates to a method for the production of pre-cast plate-like concrete elements by casting on a casting table provided on its surface with a large-area mold, particular-ly on the building site. After a short setting time for the concrete, the concrete elements together with the casting table are raised by rolling away the table on curved runners reaching to the front edges of the table. The concrete elements in the raised position are drawn off from the large-area mold and are stored in the position thus assumed.

Description

~:1 0~737 Method and arrangement for the manu~acture of pre-cast plate-like concrete elements on the building site .

The invention lies in the field concerning the manufacture of pre-cast concrete elements. It ha~ the object of providing a method and an arrangement for the manufacture of pre-cast plate-like concrete elements - referred to in short as "elements" from now on - on the building site. The invention has the further object of providing a method whereby, with the help of simple additional devices, such structures as, e.g. hollow interior walls and two-sheet, highly-insulating exterior walls can be manufactured.

~arge-area wall and ceiling elements of very smooth concrete can play a sub~tantial role in the long-overdue ratlonalisation and modernisation in housing construction. In contrast to conventional ma~onry these elements have the advantage of being able to serve simultaneou~ly as heat transfer elements and canals for ventilation, heating and installations. As opposed to light-weight constructions, they have the advantage of en~uring better sound-proofing, heat retention and refractoriness, as well as greater durability.

For interior walls, particularly dividing walls in houses or flats, the elements are constructed as ribbed walls. Two ribbed walls are 30 positioned in each case that their rib~ interlock. The ribs can be chosen to be so strong as to act as supporting component parts.
Continuous hollow space~ occur between the ribs~ which can be made use of for heating and installation ~ purposes.

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ilO1~737 ~or the outer walls, the elements are constructed as highly-insulating, two-sheet component parts, this being done in several consecutive stages whereby an element is produced consisting of a ribbed wall, between whose ribs a very strong insulation layer of hard-foam plates is embedded, projecting above the ribs.
~he front edges of the ribs are al~o insulated. ~inally with the help of 510ts provided in the hard-foam plates, a facing of cement mortar with pre-determined breaking points is poured over. ~etween the hard-foam insulation and the ribbed wall, hollow spaces are provided which can be used as air-circulation canals and which separate the facing and the ribbed wall acoustically from one another in such a way that the elemen-t becomes a two- -sheet wall. All these working stages are carried out according to the invention on a special horizontal table.
After a short setting time the table and element are raised, the element placed in a vertical po~ition, and the table brought back to its horizontal po~ition so that the next element can be concreted. ~he elements stacked vertically do not require any further special support~ ~hey are left standing until they have achieved their full rigidity.

~he invention provides a method for the production of pre-ca~t plate-like concrete elements by casting on a casting table provided on its surface with a large-area mold, particularly on the building ~ite J characterized in that after a short setting time for the concrete, the concrete elements together with the casting table are raised by rolling away the table on curved runners reaching to the front edges o~ the table, and in that the concrete elements in the raised position are drawn off from the large-area mold and are stored in the position thus assl~med.

ll~)U737 One advantage of this method lies in that a small specialized operating force with little expenditure on appara-tus can manufacture all necessary elements for a building project and that the excavation need only be started after com-pletion and hardening of all elements, with the help of a mobile crane the building can then be put up in a few days. In this way, the costs for machinery being used are kept to a minimum.
The method, in a more specific embodiment, is charac-terized in that the runners of the casting table are circularly curved and that the centre of curvature lies at the centre of gravity of the concrete element. When drawing off the concrete element from the large-area mold, the casting table is pushed back in relation to this by at least the breadth of the element to be subsequently concreted. At the same time, a shed accord-ing to the invention is pushed back by at least the breadth of the following element. The mold inserts necessary for the pro-duction of ribbed walls according to the invention are jointed into a grillage which is hung from the ceiling of the shed and by means of a winch is drawn off from the ribbed wall and either raised to the ceiling or lowered respectively. m e cable being driven by the winch according to the invention is led over rollers in such a way that the raising and lowering respectively of the casting table can also be effected by means of this winch.
An apparatus in accordance with the present invention for casting plate-like concrete wall elements comprises a cast-ing table, and a wide area mold affixed thereto. The casting table is supported by a pair of curved runners, and the casting table is stable when the wide area mold is in a horizontal position and rockable upon the pair of curved runners to place the wide area mold in substantially a vertical position.
Removal means are operable to separate the wide area mold from the concrete wall element when the wall element is in a vertical ( ,~; - 3 -,, ~ ..,~

position. The removal means can include a member forming the lowest part of the wide area mold when the wide area mold is in a vertical position.
A preferred embodiment of the apparatus in accordance with the invention provides for the casting table standing on sled-like understructures which enable it to be rolled away and thus raised into a vertical position on the understructures.
The runners for the casting table according - 3a -to the invention are circularly curved with the centre o- curv~ture lying at the cen-tre of gravity of the element to be concreted. The curvature of the runners is so designed that the moments resulting during lifting and lowering of the -table correspond as nearly as possible to a desired pattern of moments. The lowest part of the casting table mold according to the invention consists of a support not being rigidly connected -to the rest of the mold framework The casting table according to the invention is provided with winches, with whose help one can press against the support and thus draw off the casting table.

The invention further provides for winches suitable for use in connection with the above-mentioned casting table, being characterized in that their lift is sufficiently large as to allow the casting table to be pushed further during the withdrawal process immediately into the next concreting position.

In a special embodiment of the invention, the casting table is provided with claws which prevent the concreted element from sliding prematurely off the mold framework during the erection process.

According to a preferable version of the invention, a movable shed is provided, standing on rollers and being moved together with the casting table. The movable shed according to the invention is characterized by having a rod against whose end the casting table pushes when being moved on, so that the shed itself is moved on by the same amount as the table. The movable shed according to the invention is provided further with a winch and a cable being led over rollers, by means of whicn cable the casting table can be raised. In addition, the ceiling of the movable shed according to the invention has further rollers attached to it over which the cable , --3- - 5 llV(~7~37 can be pas3ed so that with the help of -the winch further casting elements can be wound up and let down.

Further advantages and details of the invention are described in the following :

A preferred version of the set-up is ~hown in the diagram, ,,- ~ : ~ , . .

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-` 6~ '7;37 ~igs. 1 and 2 show two lateral views of the erectable casting table according to the inventio~ in the horizontal posit~on which it assume~ during concreting.
Fig. 3 shows a movable shed in which the casting table is accommodated, and which is provided with additional devices for making ribbed walls.
Fig. 4 shows a detail of the withdrawal device for -the casting table shown in Figs. 1 and 2 .
~ ig. 5 shows an isometric representation of the movable shed with partly raised casting table.
Corresponding part~ are provided with the same reference symbols in the figures.
~he casting table 1 stands on two sled-shaped under-structures 2, being connected by support 3 and a structural girder 4 which is rigid in all directions.
~hese components are braced to a rigid supporting frame by means of steel cables 5 which are provided with stretching devices 6. ~he distance between understructures

2 is so chosen that support 3 bends minimally under load.

The supports 7, which can for ex. be customary wooden mold supports, are attached in cros~,direction on the supports 3, and the large-area mold 8 is then attached to the support 7. The support~ 7 and the mold 8 can be of wood or steel as according to the size of the form being produced. ~he supporting frame stands with the ,understructures 2 on strong lengths of squared timber (crane beams, for ex.) 9, which are laid exactly horizontal and at the same level on the ground. For exact positioning a mortar bed i~ to be recommended.
It is also possible to use some other foundation of ,adequate rigidity, for 6X, concrete-reinforced slabs or steel supports. ~he side facing the bent part of the , "

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understructure 2 becomes the underside, Support 7 and mold 8 do not reach right to the bottom. ~he lowest par~ of the mold is formed by a support 10 running the whole leng-th o~ the casting table. ~his support 10 is laid on the supporting frame. It is no-t rigidly connected to the rest of the mold, Fig. 4 shows a detail of the casting table in raised position. On the underside of the understructures 2 there is in each case a tripod 11 attached. A bushing 12 provided with an internal thread i8 welded onto the tri-pod. A strong threaded rod 13 having a turning device 14 is screwed through the bushing 12, The threaded rod projects through a hole 17 in support 10 to reach into a threadless bushing 15 similarly welded onto support 10. ~here is a fixture 16, which for ex, can consist of two checked nuts, on the threaded rod 13. In addition there is a claw 18 attached to the tripod.

The casting table 1 is accommodated in a movable shed 20.
~his can be of simple wooden beam construction or of a steel pipe constructio~ with an asbesto~ cement or some other covering, It stands on rubber-tyred rollers 21 which rest on the already-completed concrete components, A supporting framework 23, to which the already-completed walls are attached in vertical position~ is attached to the crane beams 9, ~hese frameworks have ~upports 24 on which the rollers 21 stand before the first walls have been completed, On the other side the shed 20 stands on rollers 22 which run on the crane beams 9. ~he shed can be attached by means of clamp~ or other devices to the crane beams 9 and the framework 2~, or to the already completed walls, so that it cannot be lifted by wind force~, .' . "~, ' 7;it7 The lateral bounding framework is attached to the large-area mold 8. It can consist of a few rigid metal girders which are screwed on and can therefore be postitioned with high accuracy. In the region of the understructures 2 the bounding framework con~ists of short length~ of squared timber 19 which are inserted.

~he walls are so produced that they are first of all concreted on the horizontally-positioned table 1 After a short hardening time they are raised by rolling back the table on the runners of the understructures 2. If the curvature of the runners is chosen to be circular and such that the centre of curvature lie~ at the centre of gravity of the concrete elements, only the centre of gravity of the casting table is lifted during erection.
A relatively small re3toring moment occurs in each case during lifting and lowering. Since the position of the centre of gravity of the casting table can be influenced by constructive measures, the curvature of the runners and the position of the centre of gravity can be optimized accordingly. In particular, for reasons of stability, a restoring moment is ~aintained. In order to forcefully control the erection proces~, the table 1 has a hook 25 attached to it, in which a cable 26 is hung by means of an eye. ~he cable 26 runs over rollers 27 to a winch 28 being provided with a ratchet. By turning the winch the wall can now be raised and the table, having been drawn off from the wall, can be lowered again. The curvature of the runners can now be optimized so that the forces in cable 26 are constant and minimal. The resulting sled shape is not exactly circular, and an instantaneous centre curve is formed by the centre of curvature.

~he claws 18 prevent the pre-cast wall from slipping prematurely off the casting table during the erection process When the wall ha~ been lifted into vertical " .

.) llV~737 position, it stands on the crane beams 9. The lengths of timber 19 used here as lateral bounding framework and which are not removed, prevent any escape of the still-fresh concrete.

The mold framework must now be drawn off from the wall.
Since thc concrete is still fre~h, there is a danger of its escaping. A device is therefore necessary which distributes the forces arising during withdrawal over as large a surface area as possible. This device is provided by ~upport 10. By turning the threaded rod 13 to the right, it presses against the support 10. Since this represents the lowest part of the mold framework, it presses against the wall over its whole length, thus pulling the framework off. The support must be sufficiently rigid as to ensure that the bending occurring in it is small enough to exclude cracks in the concrete. It serves no purpose however, -to further increase the rigidity~ since in so doing the forces necessary for the withdrawal are higher because the withdrawal process spreads more quickly over the whole molding surface.

When the ~old framework has been drawn off, the table 1 can be immediately brought into the new position by turning the threaded rod further until the casting table has moved far enough away from the wall to make room for the next wall. If the threaded rod 13 is now turned to the left, the fixtures 16 press against the support and draw it away from the wall. Since the endsof the threaded rod project into the bushings 15, it does not tip. ~y further turning to the left the table is pulled back to its starting position. The casting table is now lowered into the horizontal position and the next wall or ceiling respectively can be concreted.

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The movable shed 20 is chosen large enough to accommodate several walls, for ex. a week's production.
This guarantees that the s-till-fresh concrete walls are not immediately exposed to the weather.

In the case of the rollers 22 there is in each ca~e a rod 29 connected rigidly -to the shed 20, The rods 29 run parallel to the crane beam~ 9. When the casting table is in raised positionJ the claws 18 come in contact with the ends of the rods 29. When the casting table is pushed back with the help of the withdrawal device, the claws 18 press against the rods 29 and push the shed back. The rod is provided with horizontal holes 30~ ~he distance between these holes corresponds to the breadth of space required for each concrete element. There are cylinder holes 31 in the crane beams, occurring at intervals which are a multiple (e.g, ~ 6) of the hole intervals in the rod 29. ~he cylinder holes in the rod and in the crane beams are in alignment, '~he casting table is now pushed back until the cylinder holes match and a bolt 32 is pushed in. In this way undesired lateral displacements of the shed 20 are prevented. lhis is necessary since during the erection proce~s by the cable 26 horizontal forces are exercised on the shed.
Furthermore the bolt secures the shed on the side of the rollers 22 agalnst any lifting and an exact measure of how far the casting table must ~e pushed back in each case is achieved. ~he rollers 22 and/or 21 can possibly be omitted since with the help of the withdrawal device large forces can be exercised. ~he shed is then moved by sliding on its bearing surfaces. At the side of the erected walls the shed can be secured agalnst lifting by hanging the cable 26 on the underside of the last wall and drawing it tight with the winch 28.

For the manufacture of ribbed walls, inserts 3~ are laid on after the casting of the continuously smooth wall component. ~hese inserts consist preferably of :' ., . - . ~

sheets 34 which are bent to a trape~oidal- haped hollow body. The hollow body is filled with hard-foam plates and covered at the top with sheets 35, the~e being screwed to the sheets 34 to prevent any displacement.
~ight insert pieces of high ri~idity result. These in~erts ~ are connected to a continuous grillage 40 by means of two beams, preferably wooden pin girders, 36. The grillage is hung from the ceiling of the ~hed 20.
Rollers 37, 38 and 39 are attached to the ceiling of the shed 20 above one corner of the casting table as well as above the centre of each of the understructures 2. ~en the grillage 40 is to be removed after concreting of the column, the cable 26 is first pas;sed over the roller 37 and hung onto a corner of the grlllage 40. With the help of the winch 28 a corner of the grillage i5 raised and loosened from the groined ceiling. The cable is now hung around the roller 38. The roller 38 i~ the ; roller lying nearer to the rciler 37. Since the grillage has already been loosened here the one side of the grillage can now be raised to the ceiling and hung from hereO
The cable can now be hung around roller 39 and the other side of the grillage can be raised and hung.
i The overarches ofthe pin girders 3~6 are constructed as approx. 50 cm broad planks, so that they can be uQed as wheelbarrow tracks. The shed is high enough to provide standing height above the wheelbarrow tracksO ~he concrete i~ mixed with the help of a mixer having a hoist, The hoi~t is high enough for the wheelbarrow to be filled at the level of the wheelbarrow tracks. The only further requirement is to lay wheelbarrow tracks from the mixer to the tracks 41 90 as to enable the elements to be concreted. If the tracks 41 are connected with one another in each case at the end of the grillage, a rotary worXing can be set up which guarantees a frictionless concrebing operation.

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Claims (10)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. Apparatus for casting plate-like concrete wall ele-ments comprising a casting table, a wide area mold affixed thereto, said casting table being supported by a pair of curved runners, said casting table being stable when said wide area mold is in a horizontal position and rockable upon said pair of curved runners to place said wide area mold in substantially a vertical position, and removal means operable to separate said wide area mold from said concrete wall element when said wall element is in the vertical position, said removal means including a member forming the lowest part of said wide area mold when said wide area mold is in a vertical position.

2. The apparatus according to claim 1, wherein said removal means comprises at least one threaded rod having a crank handle at its outer end carried in a threaded bushing on said table.

3. The apparatus according to claim 2, in which said threaded rod is operable to slide said casting table immedi-ately back into position to cast another of said plate-like elements.

4. The apparatus according to claim 3, in which said casting table has a pair of supporting claws operable to pre-vent said plate-like concrete element from sliding prematurely off of said wide area mold during the period of time said casting table is being moved to a vertical position.

5. The apparatus according to claim 4, in which a base frame is provided for supporting said casting table and in which an all encompassing shed is movably mounted on rollers on said part of said base frame which supports said casting table.

6. The apparatus according to claim 5, wherein said threaded rod is further operable to move said shed the same amount said table is moved.

7. The apparatus according to claim 6, in which said movable shed has a cable affixed to a winch means for raising said casting table to a vertical position.

8. The apparatus according to claims 1, 4 or 6, further comprising a plurality of interconnected mold inserts operable, in conjunction with said casting table, for casting ribbed walls.

9. An apparatus for casting concrete wall sections com-prising: a movable shed movably mounted on track means; a casting table movably mounted within said shed on said track means; said casting table being mounted on a pair of curved runners and having a wide area mold affixed thereto; said casting table being stable when said wide area mold lies in a horizontal position and being raisable to a vertical position by being rocked on said curved runners; removal means for separating said casting table laterally a predetermined dis-tance from said concrete wall sections after casting; said removal means being further operable to move said shed later-ally a distance corresponding to the displacement of said casting table, said removal means including a member forming the lowest part of said wide area mold when said wide area mold is in a vertical position.

10. The apparatus according to claim 9, including a plurality of interconnected mold inserts operable in conjunction with said plurality of interconnected mold inserts from said concrete wall sections prior to raising said casting table to a vertical position.