WO2019157544A1

WO2019157544A1 - Method for producing composite floors, and composite floor

Info

Publication number: WO2019157544A1
Application number: PCT/AT2019/060051
Authority: WO
Inventors: Klaus Engelhart
Original assignee: Klaus Engelhart
Priority date: 2018-02-13
Filing date: 2019-02-12
Publication date: 2019-08-22
Also published as: AT520303A4; AT520303B1; CA3091031A1; CN111712606B; EP3752688A1; EP3752688B1; CN111712606A

Abstract

The invention relates to a method for producing composite floors, in which timber elements (1) are placed directly next to one another on supports and connected to one another, and a composite floor is produced by applying a concrete layer (4). A low flexure is achieved according to the invention in that the connecting elements (2) are fastened to the timber elements (1) and then reinforcing elements (3) are placed on the connecting elements (3), wherein the reinforcing elements (2) are connected to the connecting elements (2) in a play-free manner.

Description

Method for producing composite ceilings and composite ceiling

The invention relates to a method for the production of composite ceilings, in which wooden elements are placed directly next to each other on supports and connected to each other, wherein by applying a concrete layer, a composite ceiling is produced.

The present invention also relates to a composite ceiling, with a plurality of juxtaposed wooden elements, on which fasteners are attached, and with a concrete layer, which is arranged on the wooden elements and which is provided with reinforcing elements.

As wooden elements in the above sense wooden beams should be included, which may be constructed in one piece or glued from boards, but also plate-shaped elements, which may be constructed, for example, multi-layered. In any case, a single wood element typically spans the area between two supports and as a rule several wood elements are arranged next to one another.

It is already known to construct building ceilings as so-called composite ceilings, in which typically a lower section of wood and an overlying section of concrete are produced. An advantage of such composite ceilings is that the wood layer serves as a lost formwork and thus the production is simplified. The wood layer represents a structural advantage for the room below the ceiling. In terms of strength and rigidity, composite ceilings make use of the high tensile strength of wood and the fact that the entire cross-section of the wood can absorb tensile forces, which in contrast to a pure concrete pavement, in which tensile forces can essentially only be absorbed by the reinforcement. In the case of a composite floor, the wood is essentially subjected to tension and the concrete is subjected to pressure, so that the advantageous properties of these building materials are optimally utilized.

DE 198 18 525 A discloses a wood-concrete composite element in which a wood layer is composed of a plurality of square timbers, which is connected via connecting elements with a concrete layer. In addition, reinforcing elements are provided within the concrete layer. These are already necessary to avoid cracks in the concrete layer due to shrinkage during curing. With such a composite ceiling, the advantages described above can be achieved. The strength and in particular However, the rigidity of such a composite ceiling is inadequate for some applications. Therefore, in some cases too much thickness of the material layers is required to meet the given requirements.

Similar variants are also known from WO 2009/150589 A, EP 0 352 566 A and DE 102 54 043 A.

A particular disadvantage of the known solutions lies in the fact that the wood layer due to the poor connection with the concrete layer also leads to a pressure load on the wood, which can typically only be insufficiently absorbed compared with a tensile load.

The object of the present invention is to avoid these disadvantages and to provide a method for producing a composite ceiling and a special composite ceiling, so that the strength and rigidity of the composite ceiling can be increased under otherwise identical conditions.

According to the invention, this is achieved by a method in which connecting elements are fastened to the wooden elements and then reinforcement elements are placed on the connecting elements, the reinforcing elements are connected without play to the connecting elements.

The composite ceiling according to the invention is characterized in that the reinforcing elements are connected to the connecting elements without play, independently of the concrete layer.

The essential advantage of the present invention is that the transmission of shear forces between wood and concrete is effected not only by the connecting elements, as is the case in the prior art, but also by the reinforcing elements, wherein the connecting elements as Zwi - act members. An essential aspect of the invention is that the connecting elements and the reinforcing elements are connected to each other directly and without the possibility of relative movement, so that the force transmission begins to act already with a minimal deformation of the composite ceiling. In the case of an indirect connection via the concrete layer as in the prior art, a limited relative movement between wood and concrete can take place without any significant shearing forces being transmitted. As a result, at the beginning of a load, the wood layer and the concrete layer can be deformed without appreciable forces being transmitted between them, which leads not only to a reduced strength, but also to an increased deflection under load. In the solution according to the invention, such a transfer of shear forces takes place at the boundary between concrete and wood even with minimal deflection and therefore with minimum load. Therefore, in principle, the composite ceiling can be treated as a homogeneous support, except that the elastic modulus may vary in the thickness direction.

It is also an important aspect of the invention that the forces are introduced from the wood layer via the connecting elements over a large area in the concrete layer. As a result, the materials can be optimally utilized to optimize the carrying capacity. The wood layer is loaded solely or at least predominantly on train, the entire cross section is available for receiving the load. An unfavorable compressive stress is thereby avoided.

It has proven to be particularly favorable when a connecting element is used in each case for the connection of two adjacent wooden elements. It is in itself possible to provide fasteners only for connecting a wooden element with the reinforcement. However, the double use of the connecting elements is particularly advantageous.

In this context, it is particularly advantageous if a connecting element is inserted into a groove which is formed by two adjacent wooden elements. As a result, a force transmission between a connecting element and the adjacent wooden elements is effected not only by the nails or clamps with which the connection is made, but also in a form-fitting manner via the flanks of the groove and the connecting element fitting thereto.

It is particularly preferred if the reinforcing elements are inserted in receiving grooves of the connecting elements. As a result, in particular on the construction site, the connection can be produced in a simple manner by placing the reinforcing elements, typically in the form of conventional reinforcing steel grids, on the connecting elements and hammering them into the grooves. In this case, it is helpful if the receiving grooves of adjacent connecting elements are aligned accordingly, so that only minimal deformation of the reinforcing steel grids is required in order to establish the connection.

A particularly rigid structure of the composite floor can be achieved by connecting a reinforcement element to a plurality of connecting elements.

In particular, when using one-piece solid wood beams as wood elements, it can after laying to minor height variations in the middle Area of the ceiling come because the individual bars are not completely straight. A completely flat underside of the ceiling can be ensured, in particular, by aligning the wooden elements in the vertical direction before fastening the connecting elements. This can for example be done so that individual beams that project downwards, are placed in the middle to push them slightly upwards.

The wood elements are preferably provided with a hydrophobic protective layer before the concrete layer is applied. As a result, a substantial reduction in the water absorption of the wood elements during production can be achieved, which reduces the risk of undesired deformations.

It is preferable to carry out the construction of the composite ceiling largely at the construction site, that is, first placing the wood elements on the supports, then attaching the connecting elements, and then connecting the reinforcing elements to the connecting elements, after which the concrete layer is applied. However, it is also possible to carry out parts of these activities in one factory and to deliver the composite ceiling half-finished or finished to the construction site. For example, several wooden elements can already be connected to larger units with connecting elements when they are delivered to the construction site. Optionally, then even reinforcing elements or even the concrete layer can be applied. In this way, the work on the site can be simplified and accelerated.

It has proved to be particularly favorable if the wooden elements are designed as solid wood beams. As a result, a particularly cost-effective solution can be achieved.

A structurally particularly favored embodiment variant of the invention is characterized in that the wooden elements are chamfered on their upper side, so that two adjacent wooden elements form a V-shaped groove extending in the longitudinal direction. As a result, a non-positive and positive connection with the connecting elements can be achieved. This is advantageous, in particular, when the connecting elements are designed as V-shaped profiles.

A statically particularly advantageous solution provides that the connecting elements are arranged parallel to the wooden elements. As a result, thrust forces can be transmitted over the entire length of the wood elements to the concrete layer. According to a preferred embodiment of the invention, the connecting elements are formed as profiles which have longitudinally extending webs in which receiving grooves are provided. In addition to optimum power transmission, the necessary spacing of the reinforcing elements from the boundary of the concrete layer can be ensured in this way. Particularly preferably, the webs extending in the longitudinal direction have recesses between the receiving grooves. This additionally improves the adhesion within the concrete.

Preferably, the reinforcing elements are designed as Baustahlgitter. As a result, the reinforcement can be produced simply and in all directions.

A particularly favorable embodiment variant of the invention provides that milling cuts are provided in the wood elements on a surface facing the concrete layer. In this way, the shear forces between the wooden elements and the concrete layer are transmitted not only via the connecting elements, but also directly on the boundary surface, so that an additional increase in strength and flexural rigidity can be achieved. It is particularly advantageous if the milled cuts are wedge-shaped. The wedges are provided in particular in the end regions in such a way that the base in the position of use rises towards the center and on the side facing the end a support surface is provided which absorbs the pushing forces from the concrete layer when the composite ceiling is loaded. In particular, this allows increased safety in the event of fire if the connecting elements fail due to excessive heating.

The cut-outs explained above also provide additional safety in the event of a fire if the connecting elements begin to fail due to extreme heating after prolonged exposure to fire, since then the shear forces can still be transferred.

Preferably, a sealing element is provided between two adjacent wooden elements. This prevents concrete water from seeping through between the two wooden elements during manufacture and creating unsightly discoloration on the underside. As a sealing element, for example, a bead of fire-retardant intumescent acrylic is applied to the bottom of the V-shaped groove.

The fire resistance can be increased in particular by providing a fire protection element between two adjacent wooden elements. This is in particular designed to be intumescent, ie it foams at Er- heat and prevents fire from burning into the gap between two wooden elements and prematurely destroying the wooden beams or exposing the connectors to heating that causes failure.

In the following, the present invention will be explained in more detail with reference to the exemplary embodiments illustrated in the figures. Show it:

1 schematically shows a first embodiment variant of a composite ceiling according to the invention in an oblique view with partially broken away components;

Fig. 2 is a detail of the embodiment of Fig. 1;

3 shows a further detail with partially illustrated concrete layer;

FIG. 4 is a plan view of the composite ceiling of FIGS. 1 to 3; FIG.

Fig. 5 shows schematically a composite ceiling according to the invention of Fig. 1 to

4 in an oblique view with supports;

Fig. 6 shows another detail;

7 shows an oblique view of a second embodiment variant from below;

8 shows the embodiment of Figure 7 in an end view. and

Fig. 9 shows a detail of another embodiment.

In Fig. 1, a portion of a composite ceiling according to the invention is shown with partially omitted components.

The composite ceiling consists of several wooden elements 1, which are designed as wooden beams arranged parallel to each other. In each case between two wooden elements 1, a connecting element 2 is provided on the upper side, which is designed as a profile running parallel to the wooden elements 1.

Reinforcing elements 3 in the form of structural steel gratings are connected to the connecting elements 2 in such a way that the reinforcing elements 3 run just above the wooden elements 1 parallel to them.

As can be seen from FIG. 3, a concrete layer 4 is provided above the wooden elements 1, which surrounds the reinforcing elements 3. In the illustration of Fig. 3, this is broken away at the front to represent the remaining components can. The wooden elements 1 have a substantially rectangular cross-section, wherein the upper two corners are chamfered, so that in each case two adjacent wooden elements 1 form a V-shaped groove 5 with a triangular cross-section. In this groove, an equally V-shaped profile with legs 6a, 6b is adapted in each case, which forms a connecting element 2. At the two ends of the profile in each case a web 7 is integrally formed, which in the longitudinal direction alternately upwardly projecting portions 7a and therebetween horizontally projecting mounting portions 7b.

The connecting elements 2 are connected by nails 8 with the wooden elements 1, which are driven on the one hand obliquely into the V-shaped groove 5 and on the other hand vertically through the mounting portions 7b in the wooden elements 1. Alternatively, screws or clamps are possible. In addition, gluing of the connecting elements 2 with the wooden elements 1 can be provided.

In an alternative, not shown embodiment, a connection element 2 can also be placed flat on the top of a wooden element 1, to ensure the intimate connection of the wood element 1 with the concrete layer.

At the top of the upwardly projecting portions 7a receiving grooves 9 are provided, in which the reinforcing elements 3 are received by clamping, so that they are even before insertion of the concrete without play with the connection elements 2 and thus connected to the wood elements 1. It is essential for the invention that due to the tight fit, there is always adhesion and positive locking between the reinforcing elements 3 and the connecting elements 2, so that an immediate force transmission is ensured.

The reinforcing elements are typically hammered into the receiving grooves 9 during production.

The wood elements 1 have milled recesses 10, which are machined on the concrete layer 4 facing upper sides 11 in end portions 12 of the wood elements 1. The milled recesses 10 are wedge-shaped and have a base 13 rising to the middle of the wood elements 1, so that in the direction of the ends 5 a support surface 14 is formed, can be transferred to the shear forces from the concrete layer 4. In this way, the concrete layer 4 can also be supported on the wooden elements 1 via the sections projecting into the milled-in sections 10 and thus transmit additional shear forces. These shear forces act outwards, so that the support surfaces 14 can transfer them effectively. Typically, the composite floor according to the invention is mounted at its ends on supports 15 shown only in FIG.

In the embodiment variants shown in FIGS. 7 and 8, a fire protection element 17 in the form of a spring is inserted between two adjacent wooden elements 1, which prevents a fire from rapidly spreading upwards from the bottom view 16 between the two wooden elements 1 , Preferably, the fire protection element 17 is formed intumescent.

Alternatively or additionally, a sealing element 18 may be provided in the region of the bottom of the groove 5, which prevents concrete water from seeping down between the two wooden elements 1 when the concrete is applied, and the substrate 16 is impaired by discoloration. This sealing element 18 may also have an intumescent section in order to additionally provide fire protection. Alternatively, the sealing element 18 may be arranged in the form of a bead of sealing material at the bottom of the groove 5.

The embodiment shown in FIG. 9 differs only in the embodiment of the connecting elements 2, which is why only one is shown. There are only the upwardly projecting portions 7a executed, but not horizontally projecting mounting portions. Thus, recesses 19 are present between the upwardly projecting sections 7a and thus also between the receiving grooves 9, which ensure a continuous traction in the concrete, also transversely to the connecting elements 2.

The composite ceiling can be produced by placing the wooden elements 1 individually on supports 15 and then applying the connecting elements 2 and the reinforcing elements 3, after which the concrete layer 4 is produced. However, prefabrication may also take place, so that a plurality of interconnected wooden elements 1 are already placed on the supports 15 and thereafter the connecting elements 2 and the reinforcing elements 3 are already mounted. The concrete layer 4 may optionally already be applied and cured.

Claims

PATENT APPLICATIONS

1. A method for the production of composite ceilings, in which wood elements (1) are placed directly adjacent to each other on supports and interconnected, wherein by applying a concrete layer (4) a composite ceiling is produced, characterized in that connecting elements (2 ) are fastened to the wooden elements (1) and then reinforcing elements (3) are placed on the connecting elements (2), the reinforcing elements (3) being connected without play to the connecting elements (2).

2. The method according to claim 1, characterized in that a connecting element (2) is used in each case for the connection of two adjacent wooden elements (1).

3. The method according to claim 2, characterized in that a connecting element (2) is inserted into a groove (5) which is formed between two adjacent wooden elements (1).

4. The method according to any one of claims 1 to 3, characterized in that the reinforcing elements (3) in receiving grooves (9) of the connecting elements (2) are used.

5. The method according to any one of claims 1 to 4, characterized in that a reinforcing element (3) with a plurality of connecting elements (2) is connected.

6. The method according to any one of claims 1 to 5, characterized in that the wood elements (1) are aligned in the vertical direction before attaching the connecting elements (2).

7. The method according to any one of claims 1 to 6, characterized in that the connecting elements (2) with the wood elements (1) are glued.

8. The method according to any one of claims 1 to 7, characterized in that the wood elements (1) before applying the concrete layer (4) are provided with a hydrophobic protective layer.

9. The method according to any one of claims 1 to 8, characterized in that the connecting elements (2) after placement on the supports (15) are attached to the wood elements (1).

10. The method according to any one of claims 1 to 9, characterized in that between the wood elements (1) a sealing element is introduced.

11. The method according to any one of claims 1 to 10, characterized in that between the wood elements (1) a fire protection element is introduced.

12. Composite ceiling, with a plurality of juxtaposed wooden elements (1), with a concrete layer, which is arranged on the wooden elements (1) and which is provided with reinforcing elements (3), characterized in that on the wooden elements (1) connecting elements (2) are attached, and that the reinforcing elements (3) independent of the concrete layer (4) are connected without play with the connecting elements (2).

13. A composite floor according to claim 12, characterized in that a plurality of wood elements (1) by at least one connecting element (2) are connected miteinan-.

14. Composite ceiling according to one of claims 12 or 13, characterized in that the wood elements (1) are designed as solid wood beams.

15. Composite ceiling according to one of claims 12 to 14, characterized in that the wooden elements (1) are chamfered on its upper side, so that each two adjacent wooden elements (1) form a V-shaped groove extending in the longitudinal direction (6).

16. A composite ceiling according to claim 15, characterized in that the connection elements (2) are designed as V-shaped profiles.

17. Composite ceiling according to one of claims 12 to 16, characterized in that the connecting elements (2) are arranged parallel to the wood elements (1).

18. Composite ceiling according to one of claims 12 to 17, characterized in that the connecting elements (2) are formed as profiles, which have longitudinally extending webs (7), in which receiving grooves (9) are provided.

19. A composite ceiling according to claim 18, characterized in that the longitudinally extending webs (7) between the receiving grooves (9) have recesses (19).

20. Composite ceiling according to one of claims 12 to 19, characterized in that the reinforcing elements (3) are designed as a structural steel grid.

21. A composite ceiling according to any one of claims 12 to 20, characterized in that in the wooden elements (1) milling cutouts (10) on one of the concrete layer (4) facing surface (11) are provided.

22. Composite ceiling according to claim 21, characterized in that the recesses (10) are wedge-shaped.

23. Composite ceiling according to one of claims 21 to 22, characterized in that the milled recesses (10) are respectively provided in end regions (12) of the wooden elements (1).

24. Composite ceiling according to one of claims 12 to 23, characterized in that the connecting elements (2) are glued to the wood elements (1).

25. A composite ceiling according to any one of claims 12 to 24, characterized in that the connecting elements (2) are connected by nails, staples or screws with the wooden elements (1).

26. Composite ceiling according to one of claims 12 to 25, characterized in that the wood elements (1) are provided with a hydrophobic protective layer.

27. Composite ceiling according to one of claims 12 to 26, characterized in that between two adjacent wooden elements (1) a sealing element (18) is provided.

28. Composite ceiling according to one of claims 12 to 27, characterized in that between two adjacent wooden elements (1) a fire protection element (17) is provided.

2019 02 12

Ba