EP1719857A2

EP1719857A2 - Apparatus, assembly and method for the support of formwork for storey floors.

Info

Publication number: EP1719857A2
Application number: EP06113204A
Authority: EP
Inventors: Reinerius Nicolaas Van Minnen; Kasper Timmer
Original assignee: Reka Bouwsystemen BV
Current assignee: Reka Bouwsystemen BV
Priority date: 2005-05-06
Filing date: 2006-04-27
Publication date: 2006-11-08
Also published as: NL1028986C2; EP1719857A3

Abstract

Device for the support of concrete slab formwork, wherein the device comprises at least one joist for the horizontal support of the formwork, and wherein the at least one joist is assembled with girders to form a framework. It is further preferred for at least one of the girders to be removable. The device is provided with fastening means for fastening the girders to the walls that support the floor.

Description

The invention relates to a device for the support of concrete slab formwork, and in particular to a device for the support of concrete slab formwork wherein the device comprises at least one joist. The invention also relates to an assembly for the support of floor formwork. The invention further relates to a method for the support of floor formwork.
With the systems currently in use, each of a plurality of joists is supported by struts, also referred to as constructiles, lifted upward from a lower storey floor and with the aid of an adjusting device on the struts adjusted to the correct height. In order to keep the joists and the struts in place, they should also be shored.
This lifting of the individual joists and their adjustment to the correct height and shoring them is a heavy and particularly time-consuming and labour-intensive job. Especially if a camber in the formwork has to be taken into account. In addition, the manipulation of the heavy beams and struts entails a safety hazard.
It is an object of the present invention to propose a device, an assembly and a method for supporting formwork for storey floors, wherein the support can be provided and adjusted simply and quickly without requiring much physical exertion, and wherein the safety hazard can be reduced considerably.
This object is achieved by means of a device for the support of concrete slab formwork, comprising at least one joist, wherein the at least one joist is assembled with girders to form a framework. With the device according to the invention, the joists together with the girders form a complete framework. The framework is put in place with the aid of, for example, a hoisting gear. Subsequently the struts may be placed in a simple manner and adjusted. This can take place essentially without load as the struts are not required to carry the weight of the joists during their placement and adjustment to the correct height, as a consequence of which there is no need for shoring, and the task can be completed quickly without heavy physical work. Moreover, the safety hazard is reduced to a minimum.
When the device is embodied such that at least one of the girders is removable, the device can be removed in a simple manner and used again with a following storey floor. By moving the struts after an initial setting of the storey floor from the joists to the formwork, the device becomes available again and may be removed, for example, by a hoisting gear. The struts are in any case moved regularly for the purpose of discharging stress during setting. By subsequently detaching one of the girders, a construction is obtained in the form of a fork that may be removed further in its entirety. The tines of the fork are formed by the joists. The device may then be detached from the walls and removed in the direction parallel to the joists, without disturbing the struts.
A simple and flexible device is obtained if the device is provided with fastening means for fastening the girders to walls supporting the floor. This makes the device very stable and thus allows the struts to be provided and adjusted very simply.
In a preferred embodiment, the fastening means comprise braces, provided with a horizontal surface for receiving the girders, and which are to be removably fastened to the walls. In a manner generally known, the braces can take girders of various lengths, so that said braces are reusable in different systems according to the invention that are dimensioned in accordance with, for example, buildings of different sizes.
If the braces are to be fastened to the wall by means of a bolt connection that projects through a slotted hole in the brace, wherein the slotted hole is provided with a sloping portion for dismantling the device after the floor has been constructed, the device can be dismantled in a simple manner once the storey floor has been laid. For example, loosening the bolts in the slotted hole allows the device, guided by the bolt and the slope of the slotted hole to be lowered and simultaneously to be moved horizontally, so as to release it from the formwork and at the same time from the cross-sectional side of the storey floor.
In a preferred embodiment of the device according to the invention, the orientation of the at least one joist, when the device is fastened to the walls, is essentially parallel with the walls and the girders are substantially perpendicular thereto. This embodiment is simple to construct and also simple to operate.
The joists are preferably made of aluminium. This provides a light but sufficiently strong device.
In another embodiment, the device according to the invention comprises at the cross-sectional end a peripheral formwork. This is simply mounted to the device and serves as enclosure formwork. In this context, a cross-sectional end is understood to be the side at an end of the walls.
Advantageously, a filling plate is provided at the peripheral formwork for filling up a gap between the peripheral formwork and the supporting formwork. It is often not possible to make the supporting formwork to precisely the desired size. The supporting formwork will therefore always be slightly too small. The ensuing gap may be filled up by mounting a filling plate on the device according to the invention.
The device according to the invention is further especially suitable to be provided with a guard rail at a cross-sectional end. There will then be no need to fix this to the wall separately.
The device according to the invention is particularly suitable for using in connection with a formwork comprising concrete formwork floor slabs, also referred to as broad slab floors.
In a preferred embodiment, the device can be dismantled so as to reuse the various components. For example, especially the joists can be reused in a different device that is suitable for floors with a different distance between the walls.
If a great distance has to be spanned, thus if the walls are particularly long, it is preferable to use a combination of two of the above-described devices.
The device according to the invention is advantageously provided with a hoisting structure to aid with moving the device. This makes it very simple to position and reposition the device.
In a preferred embodiment of the invention, two devices according to the invention are used for the support of the formwork of a storey floor. If the storey floor is very long, it is advantageous to use two devices according to the invention, while in addition providing joists that are supported by at least one girder of each of the two devices, and which thereby extend the support.
The above-mentioned object of the invention is further achieved by a method for the support of formwork for storey floors, wherein the storey floors are supported by at least two walls situated opposite each other, wherein the method comprises the steps of:

positioning at pre-determined positions in the walls a device or assembly according to the invention,
positioning struts under the device or the assembly,
providing the formwork,
pouring the storey floor,
after a first setting of the storey floor removing the struts from the device or the assembly to the formwork,
removing one of the girders from the device or from each of the systems of the assembly, and
removing the device or the assembly from the walls.

The device according to the invention will now be further elucidated by the description of a preferred embodiment of the invention, and also with reference to the appended drawing, in which:

Fig. 1 shows a perspective view of the joists and girders of a device according to the invention,
Figures 2a, b and c show perspective views of a brace, mounted to a wall, with a portion of a girder,
Figures 3a, b and c show perspective views of a portion of a device according to the invention with a peripheral formwork, a filling plate and a guard fence,
Fig. 4 shows a perspective view of a device according to the invention, provided with a hoisting structure, and
Fig. 5 shows a perspective view of a device according to the invention between two walls, embodied in two parts.

Referring first to Fig. 1, which shows a frame work of a device for supporting formwork for storey floors according to the invention, comprising five joists 1, and two girders 2. This frame work is mounted to two walls 3, both extending parallel with the joists 2.
Mounting to the walls 3 takes place with the aid of four braces 4, see Fig. 2a. With the aid of a bolt-and-nut connection 8, a brace is fastened to each of the two ends of the two girders 2. The bolt for the connection between brace 4 and girder 2 passes through a slotted hole in the brace 4, allowing an adjustment in the event of dimensional discrepancies between the girder 2 and the distance between the two walls 3, see Fig. 2b. The braces 4 are mounted to the walls 3, also by means of a bolt-and-nut connection 7. To each wall 3 two braces 4 are mounted, such that both girders 2 are fastened to the two walls 3. The bolts for mounting the braces 4 to the walls 3 are provided in the walls 3 at the correct height to position the joists at the desired height to serve as support for the formwork for the storey floor.
When the frame work is positioned, that is to say mounted to the walls, struts can be positioned under the joists in order to support the formwork and the storey floor to be poured. As the joists are completely fixed in the desired position, the struts are very simple to position without the necessity of balancing movable joists and of the usual shoring of the struts in combination with the joists.
The bolts for mounting the braces 4 to the walls 3 pass through slotted holes 6 in the braces, see Fig. 2a and Fig. 2b. These slotted holes comprise a sloping portion and an adjoining horizontal portion. When mounting the device to the walls 3, the bolts are substantially in the lower part of the sloping portion of the respective slotted holes 6. After the storey floor has been poured and is set, the removal of the struts is just as simple as their positioning. The device is still fixed. Subsequently, after the nuts 7 have been loosened, the device is lowered and moved forward, guided by the bolts in the slotted holes. This moving may take place by means of a hoisting structure, a preferred embodiment of which will be described below. This movement releases the device from the poured storey floor and from the formwork and is now essentially supported by the hoisting structure. By loosening the nuts 8, the braces 4 can be released from the walls 3. The device is now freely suspended in the hoisting device and may be removed and, when the walls 3 have been built to the correct height for the next storey, may be again mounted to the walls for the support of the formwork for the next storey floor.
As can be seen in Fig. 1, at one end of the outer joists 1 is provided with corner sections 9. The ends of the other joists that are at the side where the corner sections 9 are provided, are equipped with fastening pins 10. When the device is mounted to the walls 3, the joists 1, where corner sections 9 and fastening pins 10 are provided, project outside the end of the walls 3. This projecting portion is used for mounting a peripheral fence. To this end two girders 11 are placed on the joists, on which a floor 12 is fastened. To the corner sections 9 posts 15 are fastened and to the fastening pins 10 uprights 14 are fastened. The posts 15 and uprights 14 are provided with handrails 13. Girders 11, floor 12, railings 13, uprights 14 and posts 15 together form a guard fence which, when mounted forms part of the device and may therefore be placed integrally with the device, may be mounted to the wall, be removed and hoisted to the next floor to subsequently be placed there.
The device shown as example of a preferred embodiment in Figures 1-3, is further provided with a peripheral formwork 16, an adjusting beam 17 and a filling plate 18. Peripheral formwork 16 forms the enclosing formwork between the walls 3. Adjusting beam 17 serves as uppermost part of the peripheral formwork. If the height of the peripheral formwork has to be adjusted in situ, another adjusting beam 17 of a different height is provided. Since the formwork supported by the device rarely has the precise dimensions, it will in the direction parallel to the walls 3 almost always be slightly smaller than the desired size. This difference is bridged by the filling plate 18.
Fig. 4 shows the device according to an embodiment of the invention, wherein the device comprises a hoisting structure. To this end posts 15 are fastened to corner sections 9, such that posts 15 may be fixed in corner sections 9 in a vertical, as well as in a substantially horizontal position. In fig. 4 posts 15 are shown in the horizontal position. The pivoting point is then chosen such that the posts 15 in this position project above the new storey floor. At a position on the posts 15 that lies approximately in the device's centre of gravity, the posts 15 are provided with hoisting hooks 19. For reinforcement purposes, a rod 20 is provided between the hoisting hooks 19. The entire device can now be moved with the aid of a hoisting mechanism, such as a crane.
Fig. 5 shows a device according to the present invention, which is an assembly of two (sub)systems as described above, with reference also to Figures 1-4. The subsystems are embodied such that the joists of the two subsystems overlap to some extend, so that in the overlap they lie next to each other. In that case, naturally, only the outer systems are provided with peripheral formwork and guard fence. Such a device is used when the length of the floor to be poured is too great to be spanned by one sub-device. If the distances to be spanned are greater still, additional joists may be provided, supported by at least one girder of each of the two systems.
Connections and fastenings mentioned above but not specified, are considered to be known to the person of average skills in the art. Connections and fastenings are detachable to allow reuse of the components mentioned in systems of different dimensional requirements, or to make reuse more simple.

Claims

A device for the support of concrete slab formwork comprising at least one joist (1), characterised in that the at least one joist (1) is assembled with girders (2) to form a frame work.
A device according to claim 1, characterised in that at least one of the girders is removable.
A device according to claim 1 or 2, characterised in that the device is provided with fastening means (4) for fastening the girders (2) to walls (3) supporting the floor to be constructed.
A device according to claim 3, characterised in that the fastening means comprise braces (4), each provided with a horizontal surface for receiving the girders (2), and which braces (4) are to be removably fastened to a supporting wall (3).
A device according to claim 4, characterised in that the braces (4) are to be fastened to the wall (3) by means of a bolt connection that projects through a slotted hole (6) in the brace (4), wherein the slotted hole (6) is provided with a sloping portion for dismantling the device after the floor has been constructed.
A device according to one of the claims 1 to 5, characterised in that when the device is fastened to the walls (3), the at least one joist (1) is essentially parallel with the walls (3) and the girders (2) are substantially perpendicular thereto.
A device according to one of the claims 1 to 6, characterised in that the joists (1) are made of aluminium.
A device according to one of the claims 1 to 7, characterised in that the device comprises at the cross-sectional end a peripheral formwork (16, 17).
A device according to claim 8, characterised in that a filling plate (18) is provided at the peripheral formwork (16, 17) for filling up a gap between the peripheral formwork and the supporting formwork.
A device according to one of the claims 1 to 9, characterised in that at one cross-sectional end the device is provided with a guard fence (11, 12, 13, 14, 15).
A device according to one of the claims 1 to 10, characterised in that the supported formwork comprises concrete formwork floor slabs.
A device according to one of the claims 1 to 11, characterised in that the device is provided with a hoisting structure (9, 15, 19, 20) to aid with moving the device.
A device according to one of the claims 1 to 12, characterised in that the device can be dismantled so as to reuse the various components.
An assembly for the support of floor formwork, characterised in that the assembly comprises two devices according to one of the claims 1 to 13.
An assembly for the support of floor formwork, characterised in that the assembly comprises two devices according to one of the claims 1 to 13, wherein additionally joists are provided, which are supported by at least one girder (2) of each of the two devices.
A method for the support of floor formwork, wherein the method comprises the steps of:
- positioning at pre-determined positions in the walls a device or assembly according to the invention,

- positioning struts under the device or the assembly,

- providing the formwork,

- pouring the storey floor,

- after a first setting of the storey floor removing the struts from the device or the assembly to the formwork,

- removing one of the girders from the device or from each of the systems of the assembly, and

- removing the device or the assembly.