DE19602400A1 - Composite wood and concrete panel - Google Patents

Abstract

Fixing pins (19) can be used to secure the sheet metal layer (9) to the wood (13), and these can be inclined to the interface between layer and wood. They can be formed by screws, and the layer itself can be of ribbed sheet-metal, the screws being inserted obliquely at the rib roots. The ribs can be of trapezium section, with positive, negative or variable flank angles. One bottom rib edge at least can be reinforced by an angular perforated plate. The screws can have a thread at the forward end, a flange at the thread end towards the head, and an unthreaded portion between flange and head protruding into the concrete.

Description

The present invention relates to a wood / concrete Composite construction with one arranged between concrete and wood profiled layer, on a ceiling construction as well as a compound screw.

Wood / concrete composite ceilings are very economical load-bearing and Room closure components, which are wooden beams and concrete slabs combine. The load capacity, but also the deflection of the structure depends essentially on the shear connection between the concrete slab (pressure element) and the wooden beam (Tension element). The most important thing is that the thrust transmission is very stiff, d. that is, the thrust is practical can be transmitted without displacement.

Wood / concrete composite ceilings combine the advantages of wooden beams and concrete slabs and make some additional ones Advantages:

• - high load capacity
• - low deflection, no swinging
• - improved sound insulation
• - good fire resistance
• - diverse appearance
• - Economics

Etc.

Essential for achieving good structural properties - as described above; high load capacity and low deflection - is the rigidity of the bond between the concrete slab and wooden beams. Even slight shifts under Load between these two support elements cause the Compound effect practically disappears.  

Now it turns out that slim composite elements, such as nails and screws, which are loaded on thrust, in the wood relatively cause large shifts, and that the bond rigidity is therefore relatively low. This fact can be countered by using screws with large diameter or by pulling the screws will. Nails can only be subjected to tensile loads to a limited extent if they have a corresponding profile of the Have surface.

A trapezoidal steel sheet is known from CH-PS 416 032, which on the one hand is the transfer of thrust between wooden beams and concrete slab. On the other hand it is the (lost) formwork of the concrete slab. At the same time it also the reinforcement of this concrete slab, respectively. the Trapezoidal profile, which for the usual spacing of the wooden beams the whole load of concrete slab, load and payload across Direction of the wooden beams. These trapezoidal profiles are extremely inexpensive support elements, which the material Make optimal use of steel sheet. When using the profiled sheet as a transmission element for the thrust forces the same first from the wooden beam to the profile sheet and then be transferred from this to the concrete.

The thrust transmission wood-profile sheet-concrete must be as a whole to be viewed as. Depending on the geometry of the profile sheet can do this alone the composite function of concrete profile sheet take over or additional devices are required which then also with those for the transmission of the Thrust forces can be combined with a wooden girder profile sheet.

The ideal profile sheet for this purpose is the one with negative Flank slope of the beads, so-called holorib sheet. Becomes  normal profile sheet, d. H. Profile sheet with positive Slope, used, creates a pulling force between sheet metal and concrete, which by suitable sheet metal parts must be included.

The object of the present invention is the transmission the shear forces from the wooden beam to the profile sheet.

According to the invention, the object is achieved by means of a Wood / concrete composite according to the wording, especially after Claim 1 solved.

Preferably for the composite of the profiled layer with wood pin-like elements such. B. screws used. Even with the slightest stress on the very thin profile sheet (generally 0.75 mm) on thrust, this deforms to an inadmissible degree. Also one that is subject to thrust Screw deforms relatively strongly in wood. It must therefore are aimed to stress the screws in tension and these tensile forces without large deformations on the sheet transfer. This is preferably accomplished in the edge of a single one Deep corrugation of the profiled sheet. This bead can be larger by a folded sheet metal angle Thickness will be reinforced.

In order to load screws in a shear assembly on train, must they are inclined to the direction of the thrust to be picked up will. A push-pull system is then created instead the shear load.

Further preferred embodiments of the invention Wood / concrete composite are in the dependent claims 2 characterized to 10.  

In addition, one is specially designed to absorb shear forces designed screw for the wood / concrete according to the invention Composite described according to the wording of 11.

The invention will now, for example, and under With reference to the accompanying figures explained.

Show:

Fig. 1 is a perspective view of the basic structure of a wooden / concrete composite based on a ceiling structure,

Fig. 2 in cross section, the interface wood-concrete under Miteinbezug a profiled metal sheet and the composite of the invention profile sheet metal timber,

Fig. 3 shows a further variant of the wood / concrete composite in section according to the invention,

Fig. 4 in cross-section, a total solution of a wood / concrete composite,

Fig. 5 shows a further embodiment of a total solution of a wood / concrete composite,

Fig. 6 erfingungsgemäß constructed in longitudinal section connecting bolts, suitable for wood / concrete composite,

Fig. 7 shows a further embodiment of wood / concrete composite using a special composite screw,

Fig. 8 shows a further variant embodiment shown a wood / concrete composite, using the same composite member as shown in Fig. 7,

Fig. 9 shows a further embodiment of a wood / concrete composite,

FIG. 10 is again a further embodiment of a wood / concrete composite,

Fig. 11 is a wood / concrete composite construction, using a so-called nail plate and

Fig. 12 shows a further embodiment of a wood / concrete composite, using a perforated disc in the screw head.

For a better understanding of the present invention, an example of a ceiling construction 1 is shown in perspective in FIG. 1. The construction is described from top to bottom, with a floor or a so-called screed 3 being laid at the top. Special constructions such as underfloor heating, parquet floors, slab floors, etc. are dispensed with at this point, since they are immaterial to the essence of the present invention. As a rule, the floor or the construction is built on an impact sound insulation 5 . This, in turn, rests on a concrete slab 7 which, as for example in the aforementioned Swiss Patent 416 032, rests on a profiled sheet or corrugated sheet 9 . The profiled sheet 9 lies primarily on wooden beams 13 , between which wooden beams 13, for example, sound insulation 11 can be arranged. For this purpose, materials such as foamed plastic materials, fibrous panels, etc. are suitable for forming the sound insulation. Finally, a suspended ceiling 15 is shown. Of course, the ceiling construction can be designed differently and one or the other ceiling layer or component can optionally be dispensed with.

As mentioned at the beginning, it is now good for achieving Structural properties such as high load capacity and low Deflection essential that the rigidity of the composite between the concrete slab and the wooden girder is large. Already minor Cause displacements under load of these two support elements, that the composite effect is practically eliminated.

The bond with the concrete arranged above the profiled sheet is characterized by profiling, d. H. through the beads with both achieved negative as well as positive slope. Compared to the underlying wooden structure, the Composite preferably achieved by means of so-called composite screws. This prevents the occurrence of the Shear forces can deform the sheet, being in this Composite system, for example tensile forces through the composite screws and the pressure forces due to the support of the profile sheet transferred to the wood.

In FIGS. 2 and 3 a section of the structure 1 is shown in FIG. Shown in which both figures, the two mentioned composite screws now 19 are shown. Fig. 2 shows a profile sheet 9 , which is arranged between the concrete slab 7 and the wooden beam 13 , with a bead 15 with a negative slope. Fig. 3 shows an alternative bead 17 with a positive slope. The composite screws 19 are preferably arranged obliquely in the deep edge 16 of the beads 15 or 17 . The profile plate with a negative flank pitch of the beads, which is ideal for transmitting the thrust forces, such as the so-called Holorib plate shown in FIG. 2, is known from the above-mentioned CH-PS 416 032. When using similar plates, such as FIG Slope, there is a tensile force between sheet metal and concrete, which must be absorbed by suitable sheet metal parts, such as shown in Fig. 3 and designated by the reference number 23 . Also in the construction according to FIG. 2, the shear forces can be transmitted with an inserted profile 21 made of thick sheet steel to the inclined screw in the axial direction thereof, and from this to the wood as a tensile load.

Total solutions of the two constructions according to FIGS. 2 and 3 are shown in FIGS. 4 and 5. Here, Fig. 4 shows variously formed pickled steel sheet profiles 16, 24 and which may serve 26 on the one hand, to transfer the thrust forces to the obliquely set screws 19 on the other hand, in order to enhance the stiffness of the composite between concrete plate 7 and timber carrier 13. In the case of the profiled sheet 26 , it has proven to be advantageous to additionally set a composite screw 19 ' running perpendicular to the composite surface.

Fig. 5 shows a normal trapezoidal profiled metal sheet with a positive edge gradient, in turn reinforced with inlaid profiles 23, as already known from FIG. 3.

Ordinary screws with sheet metal threads can be used as anchoring in the wood 13 , but then a relatively modest rigidity arises and a large number of screws must be used. Screws with deeper rolled threads with narrow thread flanks result in a significantly improved bond rigidity. But their anchoring in wood can be so large that the screws break under the head when the thread is attached. In addition, the tightening torques are so large, especially with hard wood and in branches, that the screw can turn off in the area of the upper thread attachment. An optimal screw design must therefore be sought for a screw with a non-constant diameter, as shown for example in FIG. 6. Two of the composite screws shown in FIG. 6 in longitudinal section then also have an area 33 in the area of the head 31 , with an enlarged diameter, compared to the front area 35 seen in the direction of insertion, which is preferably equipped with a bolster tip 46 . Of course, the composite screws shown in FIG. 6 are only examples which are intended to show in which direction the design of this screw should be optimized. Of course, the design of the screw can be refined or adapted to the respective requirements. For example, the design of the head shown is not limited to the illustration shown.

In Figs. 7 and 8 show alternative solutions for the composite wood-profile plate and concrete are shown. The two representations of FIG. 7 show the composite by means of a so-called SFS composite screw, as described in European Patent No. 432 484. The advantage of this composite screw, designated by the reference number 37 , is that it has an anchoring shaft section 38 beyond the screw-in thread, which section is separated from the thread on the front by means of a flange 39 . Thus, the composite screw 37 is only screwed in as far as the flange 39 , and the anchoring or reinforcing section 38 projects into the concrete slab 7 . This additionally reinforces or anchors the composite screw 37 in the concrete slab. In the illustrations, FIG. 7 now shows the use of the SFS composite screw 37 mentioned in a conventional profiled sheet 9 , while FIG. 8 shows a so-called Holorib sheet with a negative flank pitch.

In Fig. 9, a further possible measure is shown to transmit to the screw forces from the timber to the profiled sheet 9. This is done by means of adhesive, an adhesive layer 41 being shown schematically in FIG. 9. This adhesive is additionally secured with ordinary chipboard screws 19 ' against lifting. However, this bond can be critical, as it is almost rigid in the short term, but in the long term there is the possibility of creeping under load. In addition, since the sheets are oiled upon delivery, they have to be cleaned with a solvent, which is not always unproblematic on a construction site.

Another possibility is, as shown in FIG. 10, to use ordinary wire pins or grooved nails 42 . In this case, however, a multiple of nails or wire pins is required to achieve an acceptable shear stiffness, since the force transmission to the thin sheet is particularly problematic. The thrust is transferred from the wood to the nail on the profiled sheet 9 and from there to the concrete. Therefore, only profile sheets with a negative slope of the bead flanks can be used.

Another quite possible economical alternative is shown in FIG. 11, wherein a nail hole plate 43 is used. The nail hole plate is angled and the profiled sheet 9 is fastened to the nail plate 43 together with, for example, grooved nails 42 or screws. Of course, the use of a profiled sheet with a positive flank of the beads is also possible if the perforated plate is designed accordingly, so that the lifting forces acting on the concrete can be absorbed.

Finally, a further variant is shown in FIG. 12, a perforated disk 45 being additionally used in the region of the deep edge 16 of the bead 15 when the compound screw 19 is screwed in. The advantage of this variant is that the screw 19 can be used for sheets with different flank angles on the bead. In addition, the disc 45 deforms so that a better power transmission from the screw to the profile plate is possible.

One option is also to replace it with a washer to use a composite screw, the geometry of which Screw head is designed so that it in the angle the low edge of the corresponding bead fits. However, there is then the disadvantage that one for each profile sheet used certain composite screw type with corresponding screw head geometry must be used.

The wood / concrete composite constructions shown in FIGS. 1 to 12 are of course only examples which can be modified, modified or supplemented in any manner. For example, it is possible to design the profile of the sheet, ie the individual profiles in the sheet, differently than as shown in the figures described above. Another example is shown as a representative of other possible profile constructions in FIG. 13. In particular, there was no discussion of the choice of material for the composite screws used or of the profiled sheet, since this choice of material per se is not essential for the essence of this invention. Steel sheet is generally used for profiled sheet metal, although it is of course also possible to use non-ferrous and coated light metals as well as correspondingly stiff deformed foils made of reinforced plastic. The configuration of the beads can also be different, so it is of course also possible to use rectangular beads or other types of beads with round edges.

The basic idea of the present is essential to the invention Invention that the corrugated sheet used between concrete and wood with the wood through fasteners at least is largely rigidly connected.

Claims (12)

1. Wood / concrete composite construction with a profiled layer arranged between concrete and wood, characterized in that the profiled layer ( 9 ) is formed protruding into the concrete ( 7 ), and with the wood by means of connecting means ( 19, 19 ', 37, 42 ) is firmly connected. 2. Construction, in particular according to claim 1, characterized in that the profiled layer ( 9 ) with the wood ( 13 ) by means of pin-like elements ( 19, 19 ', 37, 42 ) is connected. 3. Construction, in particular according to claim 1 or 2, characterized characterized in that for the connection of the profiled Layer with the wood pin-like elements are provided which is angled to the boundary layer between profiled Layer and wood are arranged trending. 4. Construction, in particular according to one of claims 1 to 3, characterized in that it is in the connecting means are screw-like or pin-like elements. 5. Construction, in particular according to one of claims 1 to 4, characterized in that the profiled layer is a corrugated sheet or a profiled sheet and the pin-like elements in the area of the profile approach or in the region of the deep edge ( 16 ) of the respective bead in the direction against the profile into the wood at an oblique angle, firmly connect the profile plate to the wood. 6. Construction, in particular according to one of claims 1 to 5, characterized in that the profiled layer is a corrugated sheet with trapezoidal beads ( 15, 17 ) with negative or positive or variable flank pitch, and that preferably at least one of the bead edges lying on the wood is reinforced by means of an angled angle element ( 21, 23, 24, 26 ), and that the pin-like element firmly connects the profiled layer with the wood through reinforcement and corrugated sheet. 7. Construction, in particular according to one of claims 1 to 6, characterized in that the profiled layer is additionally reinforced by means of a perforated plate and / or a nail plate ( 43 ), the connecting elements both the perforated plate or the nail plate and the profiled layer join together with the wood. 8. Construction, in particular according to one of claims 1 to 7, characterized in that the connecting means are composite screws, consisting of a front thread ( 37 ), a flange arranged at the head end of the thread ( 39 ) and a threadless arranged between flange and head Shank ( 38 ) intended to protrude into the concrete. 9. Construction, in particular according to one of claims 1 to 8, characterized in that the profiled layer with the wood at least in some areas by means of an adhesive connected is. 10. Construction, in particular according to one of claims 4 to 9, characterized in that the screw-like element arranged in the deep edge of the bead has a perforated disk ( 45 ) in the region of the head, through which the screw extends and which thus results from the screw being screwed in is deformed to be adapted to the flank angle of the low edge. 11. Compound screw for a wood / concrete composite construction according to one of claims 1 to 10, characterized in that the threads have at least two zones, a front zone ( 35 ) with a smaller diameter and a rear zone ( 33 ), close to the screw head ( 31 ) with an enlarged diameter and optionally a bolster tip ( 46 ). 12. Ceiling construction, characterized in that it is a Wood / concrete composite construction according to one of claims 1 to 10 has.