EP0153660B1 - Concrete form element for the construction in permanent form - Google Patents

Abstract

In a formwork assembly for concrete wall structures side wall portions are provided at their edges with grooves and projections engageable therein for securing side wall portions together in a proper position, with the side wall portions being connected by connecting members and possibly end wall portions as required. On their inside surface, each side wall portion has engagement means to which the connecting members can be secured in the appropriate position. The engagement means may be formed by interengaging recesses and raised portions, ball portions and ball-receiving sockets or shallow detent grooves. Adhesive may also be employed for additional strength. The side wall portions may be used as insulating panels for walls, roof and floors.

Description

The invention relates to a formwork element for the shell concrete construction, in particular made of rigid foam, according to the preamble of claim 1. Such a formwork element is known from DE-U-7 120 078.

Known large-sized formwork elements (DE-B-26 18 125) can be used in a variety of ways in a network and enable cost-effective and fast construction of buildings with good external and internal thermal insulation.

From DE-U-7 335 733 a formwork element for the shell concrete construction made of rigid foam with side walls is already known, which are provided at their edges with grooves and tongues for securing the position and can be connected by webs, the side walls being provided with snap-in points on their inside , on which the webs can be positioned. The connecting elements are inserted with T-shaped or L-shaped grooves with transverse profiles and can only absorb relatively low compressive forces. From DE-U-7 625 460 a prefabricated element with at least two mutually parallel and spaced plates made of, for example, clamping material is known, in which the plates are connected by spacers to plate-like extensions by gluing. The spacers are made of steel and are directly bonded to the panels in a dimensionally stable manner.

In view of the diverse requirements for such formwork elements, improvements are desirable. In particular, the formwork elements should be stable and resistant to internal and external loads with regard to the often storey-high concrete backfilling, and should allow for cheap manufacture and space-saving transport.

The invention is therefore based on the object to formwork elements for the shell concrete construction create that can be used universally, can be produced cheaply with short cycle times, can withstand high loads, especially when filling with concrete, require little transport and storage space and can also be used as insulation boards for a wide range of uses.

The solution to the problem is characterized in claim 1.

In this way, it is possible to be able to produce the side walls and the connecting webs separately and from different materials. This makes the manufacturing forms easier and cheaper and enables short cycle times. In contrast to connecting bars made of hard foam, for example, when the formwork elements are manufactured in one piece, the concrete prevents a fire from breaking through. The storage and transport costs remain low because the individual parts first have to be assembled at the construction site or in a regional interim storage facility. This is in contrast to known formwork elements (US-A-4 223 501), in which connecting webs in the form of metal grids or sheets are inserted into the mold during manufacture. This is difficult and cumbersome and also leads to cold bridges because the metal parts end relatively close to the outer surface for secure anchoring. The also known, subsequent insertion of sheet metal connecting webs into prefabricated slots or grooves (US-A-3 788 020) leads to a serious weakening of the side walls through the slots or grooves and also creates cold bridges.

The material of the connecting bridges can also be chosen so that the dreaded acoustic bridges are avoided and the clairaudience of the buildings can be eliminated.

There are numerous possibilities for the formation of the side walls, the connecting webs and the end or intermediate walls and their mutual fastening. In a further development of the invention it can be provided that the snap-in points are undercut by a shallow depression Edges are formed, into which an adapted counterpart can be inserted in a latching manner. Conversely, the snap-in points can also be formed by a flat elevation with retracted edges onto which an adapted counterpart can be latched. A snap-in or clip connection is then created between the side wall on the one hand and the connecting elements or other parts on the other hand, which pulls the two parts against one another. In addition, an adhesive can be applied or sprayed on before snapping into place. The depression or the elevation can be relatively flat, for example a height or depth of 2 to 5 mm, so that there is practically no weakening of the side walls. The shape of the depression or elevation and the corresponding counterpart can be selected depending on the circumstances. However, a circular shape is particularly useful.

Another advantageous development of the invention provides that the locking points are formed by a ball socket or a ball for locking a ball or a ball socket. The ball or the ball socket can be arranged on an elevation or at the bottom of a depression, which expediently has a circular shape. If the connecting webs each have a contact surface at both ends, which are designed as a counterpart to the elevation or depression and / or the ball or ball socket, it is possible to additionally and extensively glue the surfaces lying against one another. The ball and the ball socket should be designed so that a certain amount of tension remains after the assembly, which ensures secure contact and a good glue point. To further enlarge the adhesive surface, the contact surfaces can be provided with extensions that extend beyond the elevation or depression.

According to a further development of the invention, the latching points can also be formed by grooves arranged at the same distance from one another, running from top to bottom and distributed over the entire inner surface of the side walls. The cross section of the grooves can be rectangular or so be that the grooves are widened at their base, for example, have the shape of a dovetail. Formwork elements designed in this way can be manufactured with practically any desired length or cut to the required size. The grooves improve the adhesion of the side walls to the concrete, so that the penetration of water into the gap between the side wall and the concrete is prevented and, moreover, no tones can occur when the side wall strikes the solidified concrete. The recess in the grooves creates webs between two adjacent grooves, the cross-section of which can advantageously be complementary to the cross-section of the grooves. The tongue and groove surface of the side walls has a shock-absorbing effect when pouring the concrete, which often falls from a relatively high height. Individual chunks are then spring-loaded and do not lead to the formwork elements being destroyed by bursting.

The side walls are preferably made of rigid foam. However, other materials can also be used. In particular, it is possible to connect side walls of different types to one another. For example, a hard foam side wall can be used on the outside of a building and a gypsum fibreboard can be used on the inside. Other combinations, also with mineral insulating materials, are possible. The material of the connecting webs is expediently chosen so that a good connection is achieved and there is no risk of fire breakdown. In addition to normal concrete, lightweight concrete (vermiculite) is also suitable. When, for example, rigid foam and concrete are bonded, curing times are considerably shorter than with a bond between two hard foam parts because the solvents can escape from the bond point more quickly. To increase the tensile strength, the connecting webs can have one or more reinforcing bars in the central area, which are either exposed or already cast with concrete. Concrete connecting webs can also have coaxial bores from both ends, which are in one end a short distance from each other. The remaining concrete residue between the two bores prevents fire penetration, but on the other hand can be easily pierced later, for example for the convenient attachment of fastening or support parts and also for the passage of lines and pipes. Finding the correct point is particularly easy when the side walls have centering points on their outside which identify the position of the connecting webs and, if appropriate, their bores.

The shaft can have at least one circumferential groove at the transition to the end plates. Reinforcing bars can be inserted correctly positioned in this groove. Two adjacent grooves allow such bars to cross.

If, according to the exemplary embodiment explained, the snap-in points are formed by grooves arranged at the same distance from one another, running from top to bottom and distributed over the entire inner surface of the side walls, the contact surfaces on the end plates of the connecting webs have an adapted shape with alternating grooves and tongues. Even if the grooves in the side walls are undercut, the corresponding tongues of the end plates can have a rectangular or square cross-section so that they can be easily inserted. A high degree of strength is achieved through large-area gluing. Because of the continuous grooves on the side walls, the connecting webs can be attached at the desired height and at any point. If the end plates are attached in such a way that they bridge the vertical or horizontal gap between formwork elements, they also serve to connect adjacent elements. Several formwork elements can be connected at the joint between a horizontal and a vertical gap.

The outside of the side walls can be provided with a raised or recessed grid, which enables parts of the formwork elements to be cut to size on the construction site. A cross grid or a pattern of parallel vertical lines can be provided. The depth of the corresponding channels or the height of the corresponding webs only has to be so large that a correct detection is possible.

When joining formwork elements on the face side, no end plates are required. At building corners, at connection points between the outer and inner walls and, for example, also on door frames or window openings, the formwork elements must be closed on the end faces. End walls or panels or intermediate walls therefore need only be provided at these points. The end walls can either be glued butt-jointed or can also be equipped with positioning elements on their side edges abutting the side walls, which interact with complementary elements of the side walls. The positioning elements can consist of pins with assigned bores or grooves with assigned springs. When using adhesive, no undercuts are expediently provided so that the end or intermediate walls can be pressed in and do not have to be pushed in, since the adhesive used would be pushed away.

The formwork elements according to the invention can be adapted to all practical requirements with the help of only one type of side wall, associated connecting webs and only one end wall. So there is no need to use special corner elements and other connecting elements of different shapes.

When using rigid foam, a fire-retardant rigid foam of class F is used to eliminate the risk of fire.

Fig. 1

die perspektivische Ansicht eines Ausführungsbeispiels für ein Schalungselement nach der Erfindung;

Fig. 2

schematisch eine geschnittene Teilansicht im Bereich der Verbindungsstelle zwischen einem Verbindungssteg und einer Seitenwand;

Fig. 3

eine komplementäre Ausführungsform der Verbindungsstelle gemäß Fig. 2;

Fig. 4

eine abgewandelte Ausführungsform für eine Verbindungsstelle zwischen einem Verbindungssteg und einer Seitenwand;

Fig. 5

eine Schnittansicht durch ein Schalungselement gemäß Fig. 1 im Bereich der Verbindungsstege;

Fig. 6

ein weiteres Ausführungsbeispiel für ein Schalungselement nach der Erfindung;

Fig. 7

eine Eckverbindung unter Verwendung von Schalungselementen und Verbindungsstegen gemäß Fig. 6;

Fig. 8

eine T-förmige Verbindungsstelle unter Verwendung von Schalungselementen und Verbindungsstegen gemäß Fig. 6;

Fig. 9

einen Deckenabschluß unter Verwendung von Schalungselementen und Verbindungsstegen gemäß Fig. 6.

Exemplary embodiments of the invention are described below with reference to the drawings. Show it:

Fig. 1

the perspective view of an embodiment of a formwork element according to the invention;

Fig. 2

schematically a sectional partial view in the area of the connection point between a connecting web and a side wall;

Fig. 3

a complementary embodiment of the connection point of FIG. 2;

Fig. 4

a modified embodiment for a connection point between a connecting web and a side wall;

Fig. 5

a sectional view through a formwork element according to Figure 1 in the region of the connecting webs.

Fig. 6

a further embodiment of a formwork element according to the invention;

Fig. 7

a corner connection using formwork elements and connecting webs according to FIG. 6;

Fig. 8

a T-shaped connection point using formwork elements and connecting webs according to FIG. 6;

Fig. 9

a ceiling finish using formwork elements and connecting webs according to FIG. 6.

The embodiment of a formwork element according to the invention shown in perspective in FIG. 1 has two side walls 10 made of fire-retardant rigid foam, which are connected to one another via two webs 11 and an end wall 12. For the form-fitting assembly of formwork elements of the same type standing side by side or one above the other, the upper and lower edges as well as the front edges of the side walls 10 and the upper and lower edges of the end wall 12 are provided with webs 13 or complementary grooves 14 which are circular in cross section with a short approach are trained. To assemble the springs 13 are inserted into the grooves 14. Trough-shaped depressions 15 on the inside of the side walls 10, which can optionally also have an undercut shape, effect an additional fixing of the side walls to the filled and solidified concrete. On the outside of the Sidewalls 10 are arranged in the form of flat grooves 16, which enable a cut to size. Centering points 17 mark the position of the connecting webs 11.

Fig. 2 shows in more detail an embodiment for the latching point between the side wall 10 and a connecting web 11. The side wall has a flat recess 18 with an undercut edge, and the foot 19 of the connecting element 11 has a complementary elevation 20 with a retracted edge, which is located below Snap or snap into the recess 18. The shape is such that a certain amount of tension remains after clipping in and thus the connecting web 11 is held securely against the wall 10. If you glue the surfaces that are next to each other with adhesive before clipping in, this results in a very secure and tensile connection.

3 shows a complementary embodiment of the connection point between the connecting web 11 and the side wall 10. Here the foot 19 contains the shallow depression 18 and the wall 10 the corresponding elevation 20.

Another embodiment for the connection between the side wall 10 and the connecting element 11 is shown in FIG. 4. The foot 19 of the connecting web 11 has a flat, central depression 21, and the wall 10 is equipped with a corresponding elevation 22. A ball 23 is arranged in the center of the depression 21 and engages in a ball socket 24 by being pressed into it. Here, too, a residual tension is exerted on the connecting element 11 after it has snapped in, so that a secure fit and good adhesion is achieved. For better load distribution and enlargement of the adhesive surface, the foot 19 of the connecting web 11 can be provided with extensions 25 indicated by dashed lines.

5 shows a cross section through the formwork element according to FIG. 1. Two connection elements 11 arranged one above the other are in accordance with the exemplary embodiment according to FIG. 2 by snapping in with the side walls 10 connected. In the exemplary embodiment shown, the connecting elements 11 consist of concrete and have central bores 26 from both sides, which end at a distance of a few centimeters from one another. The centering points 17 on the outside of the side walls 10 mark the position of the holes 26, so that later the remaining residue between the two holes 26 can be drilled through for the passage of lines or cables or the attachment of fastening and supporting elements.

In the exemplary embodiment shown in FIG. 6, the side walls 10 alternately have grooves 60 on their entire inside, which are widened at their base and thus have the shape of a rounded dovetail. The webs 61 between adjacent grooves 60 have a cross section that is complementary to the grooves 60. The associated connecting webs 11 are expediently made in one piece from concrete. They have plate-shaped end plates 62, the outer surfaces of which have webs 63 which penetrate into the grooves 60 and grooves 64 which receive the webs 61. The webs 63, which can be continuous or interrupted, have a rectangular cross section, so that the connecting webs 11 can be inserted into the side walls 10. This can be done practically anywhere and at any height of the formwork elements. A very high strength of the connection point between the connecting webs 11 and the side walls 10 can be achieved by using a suitable adhesive.

7, 8 and 9 show examples of the possibilities that are created with the design of the side walls 10 and connecting webs 11 in accordance with the exemplary embodiment according to FIG. 6. No specially designed formwork elements are required for the corner connection according to FIG. 7. It is only necessary to cut out part of the side wall 10 at the point designated 65, so that no bridge consisting of rigid foam remains in the later finished wall, which enables fire penetration. To achieve the necessary strength of the formwork elements 10 against If the concrete pours open, the connecting webs 11 are moved as close as possible to the corner, and - as shown - they can also protrude into the opening 65. The lowest connecting web 11 in FIG. 7 bridges the gap between two formwork elements and accordingly establishes a connection. An end piece 66 closes off the corner from the outside. 6 has the same grooves 60 and tongues 61 as the side walls 10 at the edges and can therefore be inserted into the side walls while achieving a non-positive connection. The grooves and springs 60, 61 of the connecting piece 66 pointing towards the interior of the formwork element, like the free grooves 60, 61 of the side walls 10, serve for resilient padding which then dampens the dynamic forces that occur when the concrete is poured in.

8 shows a T-shaped connection point between formwork elements according to FIG. 6. Again, no special designs are required. It is only necessary to remove part of the side wall 10 at the joint at 67 so that there is again no risk of fire breakdown. The connecting webs 11 are brought close to the point 67 in order to achieve the required strength or project into this.

9 schematically shows a ceiling finish using formwork elements according to FIG. 6. When the wall height is reached, the upper part of the side wall 10 is removed from the uppermost formwork element at 69 in accordance with the thickness of the dashed line 68 shown in dashed lines up to the height of the filled-in concrete 70. Before the ceiling 68 is applied, the protruding part of the end plate 62 of the uppermost connecting web 11 can be knocked off, if necessary.

6, the connecting web 11 at the transition to the end plates 62 has two circumferential grooves 71 on both sides. Horizontal and / or vertical reinforcing bars 72 can be inserted into these.

As far as "gluing" is mentioned in the above description, it means the following: Rigid foam based on polystyrene (styrofoam) is very sensitive to the collapse of the cell walls when a solvent that is effective for polystyrene is applied. Common adhesives for polystyrene therefore do not contain a solvent that could attack polystyrene. In the context of the present invention, however, an adhesive is used which contains a solvent for polystyrene in an appropriate dilution, the dilution being selected such that the cell walls of the polystyrene are only dissolved and softened to such an extent that the surface of the polystyrene is smoothed and adjusted to the surface of the webs is made possible without the cell walls of the polystyrene collapsing. This dissolving of the cell walls in the surface area of the rigid foam surprisingly leads to a solidification of the surface of the formwork element, since the rigid foam balls from which the rigid foam is made bake together, so that a welded surface layer of the rigid foam is produced in the area of the adhesive point.

With the adhesive used, it is important to use the solvent of the rigid foam in a controlled manner. This generally requires dilution with a filler or the like based on cellulose, acrylic resin or polyester resin. can exist. This filler also has the function of filling any gaps between the formwork element and the webs. The consistency of the adhesive can be adapted to the application process, with spraying, brushing and filling.

For gluing, glue can be applied to either the web or the rigid foam or to these two parts. The adhesive applied to the webs can differ from the adhesive applied to the rigid foam, in particular it can be portions of a two-component adhesive. If both sides of the surfaces to be glued are treated with glue, then the consistency of the glue for one Side, for example the webs, on the consistency of the adhesives on the other side, ie the rigid foam, may be different. For example, one side to be glued is sprayed with an aerosol, while the other side is coated with a paste, which ensures surface leveling between the surfaces to be glued.

Appropriately processed plastic waste can be used as fillers, so that the adhesive proposed according to the invention can be offered inexpensively.

The formwork system for the sheath concrete construction can be supplemented by a further element, not shown, whereby in particular horizontal formwork end walls can be formed. This element has snap-in points on its narrow sides which correspond to the corresponding snap-in points 18, 20, 23, 63, 64 of the webs and thus can cooperate with the snap-in points 18, 20, 24, 60, 61 of the wall formwork elements. These formwork elements provided to form a horizontal formwork end wall have a width which corresponds to the length of the connecting webs 11, while the length of these elements is not critical and can be, for example, 1 m, since one can form a horizontal formwork end wall from individual pieces. For this purpose, these formwork elements expediently have tongue and groove on their small narrow sides, which can have the design according to parts 13, 14. In this way it is possible to put together a continuous, horizontal formwork end wall from individual formwork elements. Such a horizontal formwork wall is inserted into the vertically running snap-in points of the narrow sides of the side wall formwork elements 10 and held by support.

In the case of the production of lintels for window or door openings, the advantage is that the horizontal formwork end wall can be moved up or down as far as the height of the window opening or door opening corresponds. It is understood that the horizontal formwork end wall is supported in a known manner from below when casting the lintel.

With the formwork element to form the horizontal formwork end walls, complicated and expensive to manufacture special formwork elements in a U-shape can be avoided. This not only leads to a reduction in costs, but also to more convenient work at the construction site, since it is easier to maintain the correct overall height with the sliding formwork elements within the side wall formwork elements than with separate U-shaped formwork elements, the use of which is due to the necessary grid dimension leads to complications.

Claims (19)

1. A shuttering element for a facing concrete construction, more particularly of expanded foam plastics, the element having side walls (10) formed on their edges with locating grooves (14) and tongues (13) and adapted to be interconnected by connecting elements (11) and possibly end walls (12, 66) secured to the inside of the side walls (10), the same being formed on their inside with catch zones (18, 20, 24, 60, 61) for securing the connecting elements (11), the same having companion contact surfaces (18, 19, 20, 21, 23, 25, 62) to the catch zones (18, 20, 24, 60, 61), the connecting elements (11) being made of concrete at least in the region of their contact surfaces, characterised in that the connecting elements (11) have at both ends dished end plates (19, 62) which are interconnected by way of a central rod or the like and are adapted to bear on or contact the side walls (10) directly.
2. An element according to claim 1, characterised in that the catch zones take the form of a shallow recess (18) or protuberance (20) having undercut edges in which a companion element (20, 18) can catch (Figs. 2 and 3).
3. An element according to claim 2, characterised in that the bearing or contact surface has widenings (19, 25) which extend beyond the protuberance (20) or recess (18).
4. An element according to claim 1, characterised in that the catch zones take the form of a spherical socket (24) or a ball for respectively engaging a ball (23) or a spherical socket (Fig. 4).
5. An element according to claim 4, characterised in that the ball (23) or socket (24) is disposed on a protuberance (22) or on the base of a recess (21).
6. An element according to claim 1, characterised in that the catch zones take the form of equidistant grooves (60) which extend continuously from top to bottom and are distributed over the entire inside surface of the side walls (Fig. 6).
7. An element according to claim 6, characterised in that the grooves (60) widen at their base.
8. An element according to claim 6 or 7, characterised in that the cross-section of the grooves (60) is complementary to the cross-section of the protuberances (61) remaining between two adjacent grooves (60).
9. An element according to any of claims 1 to 8, characterised in that the connecting elements (11) are designed optimally for tensioning in the zone between the contact or bearing surfaces (19).
10. An element according to claim 9, characterised in that the connecting elements (11) have one or more reinforcing bars in the central zone.
11. An element according to claim 9 or 10, characterised in that the connecting elemnets (11) are formed with coaxial bores (26) which extend from both ends and which terminate a short distance apart from one another (Fig. 5).
12. An element according to claim 12, characterised in that the stem of the connecting elements (11) is formed at each transition to the end plates (62) with at least one peripheral groove (71) (Fig. 6).
13. An element according to any of claims 1 to 12, characterised in that the contacting surfaces of the connecting elements (11) and side walls (10) are stuck together.
14. An element according to any of claims 1 to 13, characterised in that the side walls (10) have on their outside centring positions (17) marking the position of the connecting elements (11) and possibly of their bores (26).
15. An element according to any of claims 1 to 14, characterised in that the side walls (10) have on their outside a raised or recessed patterning (16).
16. An element according to any one of claims 1 to 15, characterised in that the end walls (12, 66) are formed on their top edge and bottom edge, like the side walls (10), with undercut grooves (14) and tongues (13).
17. An element according to claim 16, the end walls (66) have, on their side edges engaging the side walls (10), locating elements (60, 61) co-operating with matching elements of the side walls (Fig. 6).
18. A shuttering element of expanded foam plastics according to claim 1, characterised in that the end plates (19, 62) are stuck to the side walls (10) and the adhesive contains a solvent which dissolves the expanded foam plastics in such a dilution in a loading agent that the expanded foam plastics is dissolved only to the extent that its cell walls do not collapse.
19. An element according to any of claims 1 to 18, characterised by catch zones (18, 20, 23, 63, 64) so contrived on their narrow sides as to fit together with the catch zones (18, 20, 24, 60, 61) on the inside of the side wall shuttering elements (10) with the aim more particularly of forming a horizontal shuttering closure wall in the construction of a purpose-made block.

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