EP2821561B1 - Wooden structural part and composite wood-concrete structure - Google Patents

Description

The invention relates to a wood component for a wood-concrete composite construction, wherein for surface bonding of the wood component with concrete in the composite surface to the concrete at least one engageable with the concrete and / or fillable recess is provided, which for receiving shear forces between concrete and Wooden component has at least one substantially transversely to the composite surface oriented edge.

Furthermore, the invention relates to a wood-concrete composite construction of at least one such timber component and a bearing element and a profile insert for a wood-concrete composite construction.

Wood-concrete composite structures have long been known from the prior art and consist of wooden elements or wooden components, which are shear-resistant connected to a adjacent to a composite surface of the timber component concrete component. Wood-concrete composite structures are used in the construction industry in particular, where the advantages of the building material wood should be combined with the advantages of the building material concrete. Such a construction is based on the basic idea of assigning the compressive forces to the wood in the composite cross section, above all the tensile forces and the concrete.

Wood-concrete composite construction can be used as a supporting and / or raumabschließendes component both in new construction as well as in the upgrading of existing wood or wood material constructions.

In the context of the present invention, the term timber component is to be understood as meaning all load-bearing and / or space-enclosing wooden structures which can be combined with concrete to form a wood-composite construction. These can be both ceiling and wall-forming constructions.

In the ceiling formation u.a. the so-called beam construction, consisting of a beam layer and possibly arranged thereon wooden formwork, and the so-called board stack construction of juxtaposed standing, nailed or doweled side boards used.

In addition, so-called cross-plywood or cross-ply constructions are increasingly being used. These are cross-glued layers of boards arranged side by side, similar to the construction of conventional plywood panels. Due to their areal structure, such wooden components are suitable for both ceiling and wall-forming constructions.

In order to exploit the advantages of a wood-concrete composite construction, it must be ensured that a permanent connection exists between the timber component and the concrete component, so that both longitudinal and lateral forces can be absorbed by the composite element and the composite element under all load situations static unit is to be regarded.

To absorb shear forces between the concrete and wooden component, it is known from the prior art to provide in the composite surface of the wooden component recesses, preferably so-called cervical, which are filled with concrete or are in engagement with the concrete. In order to introduce the thrust forces, which run essentially parallel to the composite surface, into the wooden component, the recesses have, as abutments for the concrete, substantially flanks aligned transversely to the composite surface. In the context of the present invention, the term transverse means not only a flank orientation perpendicular to the composite surface, but also any inclined flank orientation different from 0 ° or 180 °.

In order to prevent lifting of the concrete slab due to the Extensitätsmoments arising in the region of the recess or to absorb transverse forces between wood and concrete component, are from the prior art Various connection means known, which are firmly connected on the one hand with the concrete and on the other hand with the wood component. In addition to adhesive joints are mainly mechanical fasteners such as screws, dowels, nails u. Like. For use. For example, in the distributed over the wooden component recesses long wood screws or dowels are screwed in, which protrude perpendicular to the composite surface over the wood cross-section and anchor-like with the concrete engaged. In addition to single screws and dowels, composite systems of crossed pairs of screws or dowels inclined at 45 ° to the composite surface are also known.

Furthermore, it is off DE 298 24 534 U1 a board stack element known between the slats sheets or squared timbers are arranged, which protrude as webs in the concrete slab. The bond between wood and concrete takes place via so-called cross-tie anchors, which are inserted into recesses of the webs.

However, such fasteners are usually associated with very high manufacturing and material costs and also allow only a low degree of prefabrication. In particular, there is a risk that the connecting means projecting beyond the wooden component will be damaged when transporting a plurality of stacked wooden elements. Even walking the wooden elements on the site and laying the concrete reinforcement is hampered by the protruding fasteners.

Out DE 298 16 002 U1 is a composite construction is known in which the simultaneous absorption of shear and shear forces is achieved by a positive connection between concrete and wood. For this purpose, the wood-concrete composite construction in the area of the composite surface reinforced concrete strips, glued profiled slats or milled depressions, which extend transversely to the clamping direction of the composite structure. The strips or recesses have in cross section a conical shape and thus an undercut, which serves to accommodate Querzugkräften.

All of the aforementioned connecting means have in common that they produce a rigid bond between the concrete and the wooden component. As a result, the webs, strips, recesses and / or connecting means for anchoring the concrete or fixation of the strips and / or webs according to the composite stress, d. H. be arranged according to the course of the shear forces on the composite structure, with varying distances from each other, otherwise the utilization rate of the composite construction in a configuration with a constant distance would be much lower. Accordingly, the arrangement of the recesses and composites must be recalculated for each concrete composite construction. In addition, the rigid composite construction in the range of larger spans borders on their performance, since the power transmission potential in the region of the recesses is locally limited.

In order to allow at least an equidistant arrangement of the profile strip connecting means regardless of the course of the longitudinal thrust forces proposes DE102 54 043 B4 a wood-concrete composite structure, in which profiled for producing a non-positive composite wood ribs with a negative edge slope, ie with an undercut, are arranged on the composite surface to the concrete, but in contrast to the profiled slats in DE 298 16 002 U1 parallel to the main support direction of the composite cross section. For fixing the projecting into the concrete ribs on the wooden component pin or screw-shaped connection means or surface gluing are provided. Due to the multi-part construction of the manufacturing and manufacturing effort but also here correspondingly expensive.

The EP 1 582 644 A1 relates to a wood-concrete composite construction. In order to ensure the most stable connection between the materials wood and concrete, in dovetail recesses of the timber component appropriately adapted connectors, z. B. made of sheet steel, inserted, the projections extend beyond the wooden part and in the concrete layer. This document discloses a timber component according to the preamble of claim 1 and a wood-concrete joint construction according to the preamble of claim 15.

Object of the present invention is therefore to improve wood components and wood-concrete composite structures of the type mentioned in that a flat, durable and sustainable bond between concrete and wood can be achieved regardless of the specific course of the longitudinal thrust forces. Furthermore, the cost and time compared to the known wood-concrete composite structures be further reduced while achieving a high degree of prefabrication.

This object is achieved by a timber component according to claim 1 and a wood-concrete composite construction according to claim 15. Advantageous embodiments of the invention are the subject of the respective subclaims.

According to the invention, the wooden component is distinguished by the fact that a bearing element made of an elastically deformable material is provided on the at least one edge of the recess oriented essentially transversely to the composite surface. In accordance with the invention, it has been recognized that a certain longitudinal displaceability between the concrete and the wooden component can be achieved by a bearing element of an elastically deformable material on the flank, ie in that region of the recess in which the pressure forces from the concrete are introduced directly into the timber component , which results in an effective redistribution of shear forces within the timber component. In particular, a failure of the connecting means in the region of maximum stress, ie in the region of the recesses, can be avoided because the redistribution of the shear forces the load capacity of the wood component is used in otherwise less stressed areas with. Due to the redistribution, furthermore, the arrangement of the recesses can take place independently of the specific course of the longitudinal thrust forces. In particular, the recesses or composite means can be arranged substantially at equal intervals. Since all composite means or recesses experience approximately the same stress through the bearing elements of an elastically deformable material, the computational effort for determining the exact number and distribution of the recesses in a concrete composite construction is significantly reduced. The wood component is therefore universally applicable for various applications and less prone to error in its manufacture. Since, in particular, a differentiated distance arrangement of the composite means over the length of the carrier element is eliminated, a total of a fast and systematic production process can thus be ensured.

In order to achieve sufficient deformability of the bearing element in the range of normal serviceability of the timber component, the bearing element consists of an elastically deformable material. It is conceivable, for example, an elastomeric plastic, rubber and / or bitumen. By a suitable choice of material, the degree of deformability and thus the degree of redistribution of forces can be specifically influenced. Furthermore, it may be provided that the deformability in the limit state of the load-bearing capacity of the construction passes into a plastic or ductile deformability in order to fully exploit the rearrangement capability.

Depending on the configuration of the recess of the wood component, the bearing element may be formed substantially rod, strip, rail-shaped or the like. Thus, as recesses about milled, transverse to the main support direction Kerven conceivable, on the edges of elongated, strip or rail-shaped bearing elements, so for example rail profiles of an elastomeric plastic or bitumen strips are arranged.

In order to ensure the scheduled adjustment between concrete and wooden component and thus the redistribution of the longitudinal thrust forces, the bearing element according to a further advantageous embodiment of the invention cavities and / or chambers which allow a deformation of the bearing element with a corresponding force.

According to a further advantageous embodiment, the bearing element with the edge, in which the thrust forces are introduced from the concrete into the timber member, firmly connected. Preferably, the bearing element is glued to the flank, nailed, stapled and / or screwed. Of course, other mounting options are conceivable. Accordingly, the bearing elements on the timber component factory pre-assemble, which can increase the degree of prefabrication of wood-concrete composite construction.

Since the bearing element is arranged on the flank and thus within the recess, there are no connecting means beyond the wooden component, so that a transport of several stacked wooden components is easily possible.

According to a further advantageous embodiment of the invention, the at least one recess is formed as Kerve, in particular as milled into the wood component Kerve. The milling of the Kerve allows a particularly simple and fast production of the wood component.

Alternatively, according to a further advantageous embodiment of the invention on the composite surface to the concrete at least two laterally spaced, preferably glued and / or screwed and / or nailed webs, strips, slats, boards or the like may be provided, between which the at least one recess is formed. For fixing the webs, strips, slats, boards and the like, for example, screw, nail or glue connections are conceivable.

According to a further advantageous embodiment of the invention, the at least one recess for receiving transverse tensile forces between concrete and wooden component at least one, preferably in cross-section wedge-shaped, undercut. The undercut creates a toothing between the wood component and the concrete engaging with the recess, so that a lifting of the concrete from the timber component is avoided.

In order to achieve a combination effect for absorbing shear and transverse pulling forces between concrete and wooden component, according to a further advantageous embodiment of the invention at the composite surface to concrete at least two layers arranged crosswise from each other at least two laterally spaced apart, preferably glued and / or screwed and / or nailed bars, strips, slats, boards or the like provided between which at least one recess is formed. By this arrangement arise between the crosswise arranged layers of spaced boards at the same time also undercuts. Such a structure is preferably suitable when using so-called cross-plywood or cross-ply constructions. These are cross-laminated boards analogous to the production of a conventional plywood. The arrangement described above can for example be achieved in that the two upper layers of the cross-laminated timber are not formed over the entire surface, but that the individual boards are set to gap, so that between the resulting recesses and undercuts concrete can be introduced. Accordingly, the tensile forces resulting from the composite effect can be removed by the teeth of the concrete with the upper board layers.

In order to avoid overstressing the joint between the upper board layers and the remaining timber component cross-section, a bearing element of an elastically deformable material is provided on at least one flank of the two upper board layers, preferably on at least one flank of each board of the two layers, so that tensile stresses between concrete and wood cross-section can be evenly distributed to almost all crossed board layers. In particular, if at least one flank of each board of the two upper layers has a bearing element made of an elastically deformable material, a biaxial load transfer in the wood-concrete composite construction can advantageously be achieved due to the crossed arrangement.

According to a further advantageous embodiment of the invention, at least one recess has a profile insert adapted to its cross section, which preferably lines the recess completely, but at least in the region of the flank, the undercut and / or the bottom. In an advantageous manner, the profile insert adapted to the cross section of the recess can be used to fix the deformable bearing element on the region of the profile insert assigned to the flank. Vorzugsswiese, the profile insert a sufficient rigidity or dimensional stability in order to wear the bearing element can. Conversely, the profile insert should also be sufficiently flexible or deformable in order to be able to introduce it, if necessary, into undercuts of the recess.

According to a further advantageous embodiment of the invention, it can be provided that the profile insert at least partially covers the composite surface in the edge region of the recess, so that the profile insert is also supported on the composite surface.

By lining the recess with the profile insert is further achieved that the wood surfaces in the region of the recess, in particular relatively strong absorbent end grain areas are isolated from the otherwise immediately adjacent concrete. This prevents the freshly introduced during filling of the recess concrete is deprived of moisture by the wood, which is essential for the setting process and therefore for a good quality concrete, otherwise threaten local strength losses. In the known from the prior art wood-concrete composite constructions with Kerven or recesses, the suction effect of the end wood is thereby avoided that a film or an additional, viscous concrete vat are introduced into the recesses. Through the profile insert this operation and the corresponding cost of materials can be saved.

Advantageously, the profile insert is adapted to the shape, in particular to the cross section of the recess. It is conceivable, for example, that the profile insert is trough-shaped or U-shaped and is inserted from above into the recess or Kerve. Preferably, the profile insert is also adapted to the contour of the example wedge-shaped undercut. The length of the profile insert is also measured advantageously according to the length of the recess or Kerve.

In order to increase the degree of prefabrication of the wood-concrete composite construction, the profile insert, preferably with bearing element fixed thereto, can already be introduced into the recesses or cages at the factory.

For the above-described Kreuzlagenholz- or cross-plywood constructions are also advantageously adapted to the board width and length, U-shaped profile inserts. These can, for example, in a simple way, with the U-opening facing downwards, placed over the boards placed on the gap. Accordingly, the profile inserts for the second uppermost board position with the U-opening pointing upwards, preferably before applying or gluing the top board layer, inserted into the recesses formed by the board gaps.

According to a further advantageous embodiment of the invention, the bearing element can be either fixed on the side facing the wood component or on the concrete facing side of the profile insert, in particular glued and / or laminated.

Preferably, the profile insert made of plastic and / or metal. It is conceivable, for example, a metal sheet, preferably a galvanized sheet steel. In addition to the low material costs, these materials can be easily adapted to the shape of the recess. Furthermore, metal sheets advantageously have a sufficient rigidity or dimensional stability for receiving and fixing the bearing element, but are at the same time sufficiently flexible or deformable in order to be able to be introduced into undercut areas, if appropriate.

It is further conceivable that the profile insert is fixed to the wood component, in particular via at least one screw connection. The screw connection, if present, preferably takes place in the region of the undercut, so that the undercut is automatically reinforced by the screw connection. Accordingly, it is possible to absorb greater transverse tensile forces via the undercut. As screws suffice, for example, short full-thread screws with a length of about 5 cm, which are significantly cheaper than the usual for receiving transverse tensile forces composite screws or dowels with a length of at least 20 cm.

Another aspect of the invention relates to a wood-concrete composite construction with at least one concrete part and at least one timber component according to the invention, wherein the concrete component is engaged with at least one recess in the composite surface of the timber component. In order to absorb shear forces between the concrete and the wooden component, the recess has at least one flank aligned essentially transversely to the composite surface. According to the invention, it is provided that at least one bearing element made of an elastically deformable material is arranged on the at least one flank for redistributing the thrust forces within the timber component.

Other objects, advantages, features and applications of the present invention will become apparent from the following description of an embodiment with reference to the drawings.

Fig. 1

einen Querschnitt durch ein erstes Ausführungsbeispiel einer erfindungsgemäßen Holz-Beton-Verbundkonstruktion,

Fig. 2

eine Detailansicht des Querschnitts gemäß Fig. 1,

Fig. 3

eine isometrische Ansicht der Profileinlage der Holz-Beton-Verbundkonstruktion gemäß Fig. 1,

Fig. 4

eine isometrische Ansicht eines zweiten Ausführungsbeispiels einer erfindungsgemäßen Holz-Beton-Verbundkonstruktion ohne Beton,

Fig. 5

einen Querschnitt durch die Holz-Beton-Verbundkonstruktion gemäß Fig. 4, und

Fig. 6

einen Längsschnitt durch die Holz-Beton-Verbundkonstruktion gemäß Fig. 4.

Show it:

Fig. 1

a cross section through a first embodiment of a wood-concrete composite construction according to the invention,

Fig. 2

a detailed view of the cross section according to Fig. 1 .

Fig. 3

an isometric view of the profile insert of the wood-concrete composite construction according to Fig. 1 .

Fig. 4

an isometric view of a second embodiment of a wood-concrete composite construction according to the invention without concrete,

Fig. 5

a cross section through the wood-concrete composite construction according to Fig. 4 , and

Fig. 6

a longitudinal section through the wood-concrete composite construction according to Fig. 4 ,

The Fig. 1 and 2 show a first embodiment of a wood-concrete composite structure 100 according to the invention, which consists of a wooden component 1 and a so that over the composite surface 4 area connected concrete component or concrete 30. To absorb tensile forces, the timber component 1 has a plurality of recesses 2, in particular cervicals 3, which are filled with concrete 30 or with which the concrete 30 is engaged. In this case, any shear forces between the concrete 30 and the timber component 1 are taken up by the flanks 5 of the recesses 2 which are oriented essentially transversely to the composite surface.

According to the invention, a bearing element 10 made of an elastically deformable material is provided on each of the flanks 5. This preferably consists of an elastomeric plastic, whereby between concrete 30 and wooden component 1 a certain, on the material properties of Lagerelements 10 scheduled to be adjusted Verschieblichkeit.ergibt. This in turn causes an effective redistribution of the thrust forces and thus a uniform stress of the wood cross-section achieved in accordance with the invention. Furthermore, it is achieved that the recesses 2, which in the first embodiment according to the Fig. 1 and 2 as in the wood component 1 milled Kerven 3 are formed, regardless of the course of the longitudinal thrust forces can be distributed evenly over the wood cross section.

Since by the ve.rformbaren bearing elements all composite means or recesses 2 experience the approximately same stress, and the computational effort to determine the exact number and distribution of the recesses 2 in the concrete composite construction is significantly reduced. The wooden component 1 is thus universally applicable for various applications and less prone to error in its production.

In addition, the recesses 2 and 3 cerves each have a wedge-shaped undercut 6 in cross-section. This serves to absorb transverse tensile forces, which result from the composite action between concrete 30 and wooden component 1, so that a lifting of the concrete 30 from the timber component 1 is avoided. The undercuts 6 each show from the two ends of the timber component 1 for reasons of static reasons to its center.

In particular Fig. 2 can be seen, the recesses 2 and 3 cerves are in the region of the edge 5, the undercut 6 and the bottom 7 lined with a shape adapted to their profile insert 20, which also the composite surface 4 in the edge region 4a, 4b of the recess 2 at least partially covers. This ensures that the timber component 1 is isolated from the adjacent concrete 30 in the recesses 2, in particular in the areas of the highly absorbent forehead wood, so that the wood can not extract moisture from the concrete 30 when filling the cerverts 3. For the hydration of the cement is thus always sufficient moisture available, so that the concrete 30 on the entire cross section can achieve a sufficiently good quality and in particular locally sufficient pressure and strength properties.

In particular Fig. 3 can be seen, the profile insert 20 also serves to fasten or for receiving the bearing element 10. This is the first embodiment according to the Fig. 1 and 2 at the the timber component 1 facing side of the profile insert 20, in the region of the edge 5, glued.

The profile insert 20 with attached bearing element 10 may be formed in particular as a pre-assembly and accordingly constitutes an independent idea of the invention. Advantageously, this pre-assembly can be inserted in a single operation in the milled canned 3. The insertion into the cervix 3 can be done either at the construction site or already at the factory in the production of the timber component 1, which increases the degree of prefabrication of the composite structure accordingly.

In the present first embodiment according to the Fig. 1 to 3 the profile insert 20 consists of a galvanized steel sheet, which is adapted in cross section to the contour of the cervix 3. In the longitudinal extent, the length of the profile insert 20 corresponds to the length of the recess 2 or Kerve 3. In the flank 5 associated region of the profile insert 20 is glued as a bearing element 10, a plastic strip made of an elastomeric polymer. Conceivable, however, are other, in particular mechanical or chemical types of connection, such as screwing, nailing or laminating.

In addition to galvanized steel sheet but other materials for the profile insert 20 are of course conceivable, such as plastic or other metal sheets. Also, the bearing element 10 may be made of other materials, such as rubber or bitumen. In addition to the strip shape further rail, rod or strip-shaped bearing elements 10 are conceivable. Furthermore, the deformability of the bearing element 10 can also be realized by means of chambers and cavities within the bearing element 10.

In order to strengthen the wood cross section locally in the region of the recess, additional screws 40 or the like may be introduced into the wood. In particular Fig. 2 can be seen, the screw 40 is advantageously introduced in the region of the undercut 6 in the timber member 1 and there serves at the same time for fixing the profile insert 20 on the timber member 1 and for receiving the resulting transverse tensile forces.

The timber component 1 with incorporated profile insert 20 and bearing element 10 fixed thereto, according to the exemplary embodiment of FIG Fig. 1 and 2 , continues to offer benefits in terms of transportation. Thus, in such a wooden component 1, without concrete 30, neither screws nor other connecting means emerge from the construction, so that several of these elements can be transported in batches one above the other. In addition, such elements can easily be committed to the construction site without the risk that protruding fasteners could break off or be damaged in any other way. Furthermore, there are advantages for the installation of concrete reinforcement. This can be easily positioned on the wooden components 1 according to the invention with simple spacers, without a complicated laying around any protruding connecting means around.

The 4 to 6 show a second embodiment of a wood-concrete composite construction according to the invention 100. This is based on a timber component 1 in cross-plywood or cross-laminated timber construction, ie a wooden construction with cross-glued boards analogous to the production of a conventional plywood. With the construction shown here can be advantageously a combination effect for receiving shear and Querzugskräften can be achieved.

To form recesses 2 and corresponding undercuts 6, the two upper board layers of the cross-ply wood according to 4 to 6 not arranged over the entire surface. Rather, the individual boards 8 are set to gap, so that form between the boards 8 and board layers cavities with concrete (not shown here) can be filled. Due to the generated toothing of the concrete with the upper board layer, the tensile forces arising from the composite effect can be effectively removed.

According to the present embodiment 4 to 6 the individual boards 8 or board layers are glued or glued together. Conceivable, however, are other means of connection such as screwing or nailing.

In order to avoid overstressing the glued joint 9 between the boards 8 of the two upper layers and the rest of the cross section due to the bonding effect, the boards 8 are correspondingly arranged on at least one longitudinal side of the boards 8 in accordance with the first embodiment Fig. 1 to 3 - Formed bearing elements 10 arranged. Due to the deformability results here also about the material properties of the bearing element adjustable displaceability between concrete and cross laminated wood, so that the shear stress is distributed evenly on almost all crossed board layers. The crosswise arrangement results in addition to the uniform stress of the glue joints 9, the additional advantage of a biaxial load transfer. In addition, as already explained above, the tensile forces resulting from the composite action are removed by the toothing of the concrete with the upper board layer.

Also in the second embodiment according to the 4 to 6 Profile inserts 20 are provided, on which the bearing elements 10 are fixed and which at least partially line or cover the recesses 2.

For cross-ply constructions according to 4 to 6 are advantageously adapted to the board width and length, U-shaped profile inserts, such as galvanized sheet steel. These can, as far as the topmost board layer is concerned, simply be slipped over the gap-set boards 8 with the U-opening facing downwards. Accordingly, the profile inserts for the second uppermost board layer, preferably before the application or gluing of the top board layer, with the U-opening facing up into the gaps formed between the boards 8 inserted. For fixing the bearing elements are also various connection means conceivable, such as screw or adhesive or laminating.

LIST OF REFERENCE NUMBERS

1

timber member

2

recess

3

bird's mouth

4

composite surface

5

flank

6

undercut

7

Bottom of the recess

8th

board

9

bonded joint

10

bearing element

20

profile insert

30

concrete

40

screw

100

Wood-concrete composite structure

Claims (15)

1. Wooden structural part (1) for a composite wood-concrete structure (100), wherein for the purpose of a large-area connection of the wooden structural part (1) to the concrete (30) at least one recess (2) is provided in the bonding surface (4) to the concrete (30) which can be brought in mesh and/or can be filled with the concrete (30) and which for the purpose of receiving shear forces between the concrete (30) and the wooden structural part (1) comprises at least one shoulder (5) that is aligned so as to be substantially oblique to the bonding surface (4), characterized in that a bearing element (10) that is made of an elastically deformable material is provided at the at least one shoulder (5) for the purpose of redistributing the shear forces within the wooden structural part (1).
2. Wooden structural part (1) according to claim 1, characterized in that the elastically deformable material consists of an elastomeric synthetic material, rubber and/or bitumen, for example.
3. Wooden structural part (1) according to claim 1, characterized in that the bearing element (10) is configured so as to be substantially bar-shaped, strip-shaped, rail-shaped or the like.
4. Wooden structural part (1) according to one of the preceding claims, characterized in that the bearing element (10) comprises chambers and/or cavities.
5. Wooden structural part (1) according to one of the preceding claims, characterized in that the bearing element (10) is fixedly connected to the shoulder (5), preferably is bonded, nailed, clasped and/or screwed to the shoulder (5).
6. Wooden structural part (1) according to one of the preceding claims, characterized in that the at least one recess (2) is configured as a birdsmouth (3), in particular one that is milled into the wooden structural part ( 1 ).
7. Wooden structural part (1) according to one of the preceding claims, characterized in that, at the bonding surface (4) to the concrete (30), it comprises at least two webs, bars, rails, boards (8) or the like, which are arranged at a lateral distance to one other, preferably by being glued on and/or screwed on and/or nailed on, and between which the at least one recess (2) is formed.
8. Wooden structural part (1) according to one of the preceding claims, characterized in that the at least one recess (2) comprises at least one undercut (6), preferably one that has a wedge-shaped cross-section, for the purpose of receiving transverse tensile forces between the concrete (30) and the wooden structural part (1).
9. Wooden structural part (1) according to one of the preceding claims, characterized in that, for the purpose of receiving shear forces and transverse tensile forces, at least two layers are provided at the bonding surface (4) to the concrete (30) that are arranged crosswise on top of one other and are comprised of respectively at least two webs, bars, rails, boards (8) or the like, which are preferably glued on and/or screwed on and/or nailed on and which are arranged at a distance from one other, forming at least one recess (2) with at least one undercut (6) in between them.
10. Wooden structural part (1) according to one of the preceding claims, characterized in that at least one recess (2) comprises a profile insert (20) that is adjusted to its cross-section and that lines the recess (2) preferably completely, but at least in the area of the shoulder (5), the undercut (6) and/or the base (7).
11. Wooden structural part (1) according to claim 10, characterized in that the profile insert (20) covers the bonding surface (4) in the edge area (4a, 4b) of the recess (2) at least in certain parts.
12. Wooden structural part (1) according to claim 10 or 11, characterized in that the profile insert (20) is fixedly arranged at the wooden structural part (1), in particular by means of at least one screw connection.
13. Wooden structural part (1) according to one of the claims 10 to 12, characterized in that the profile insert (20) consists of a synthetic material and/or metal, in particular a sheet metal, preferably made of a galvanized steel sheet.
14. Wooden structural part (1) according to one of the claims 10 to 13, characterized in that the bearing element (10) is fixedly arranged, in particular glued on and/or laminated, at the profile insert (20) in the area that is allocated to the shoulder (5), preferably on that side of the profile insert (20) which is facing the wooden structural part (1).
15. Composite wood-concrete structure (100), comprising at least one concrete structural part (30) and at least one wooden structural part (1) according to one of the preceding claims, wherein the concrete structural part (30) is in mesh with at least one recess (2) in the bonding surface (4) of the wooden structural part (1), which for the purpose of receiving shear forces between the concrete (30) and the wooden structural part (1) comprises at least one shoulder (5) that is aligned so as to be substantially oblique with respect to the bonding surface (4), characterized in that a bearing element (10) that is made of an elastically deformable material is provided at the at least one shoulder (5) for the purpose of redistributing the shear forces within the wooden structural part (1).

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