SURFACE BODY, IN PARTICULAR THE FLOOR SLABS OF A BUILDING, COMPLETING SEVERAL SURFACE ELEMENTS MADE OF WOOD

Abstract

The invention relates to a planar body (1), in particular a floor slab of a building, comprising several planar elements (10) arranged adjacent to one another in a first plane (E1) and at least a second plane (E2). According to the invention, shear-locking elements (12) are formed in the surfaces (11) of at least some of the planar elements (10) between the first plane (E1) and the second plane (E2), forming a planar interlock that prevents the planar elements (10) from sliding against one another. The invention also relates to a method for manufacturing such a planar body (1).

Description

[0001] The invention relates to a planar body, in particular a floor slab of a building, comprising several planar elements arranged adjacent to one another in a first plane and at least a second plane. The invention further relates to a method for manufacturing such a planar body, in particular a floor slab of a building. STATE OF THE ART

[0002] Multi-story buildings are typically constructed from floor slabs, which form individual accessible levels and between which several vertical support elements extend. These floor slabs are usually made of reinforced concrete, but the use of concrete is inherently associated with high CO2 emissions, whereas the use of wood for floor slabs sequesters CO2. Therefore, it is desirable to avoid using reinforced concrete for floor slabs wherever possible and to use wood, with the aim of giving the floor slabs a load-bearing capacity comparable to that of a reinforced concrete floor slab.

[0003] The floor slab should not be significantly thicker than conventional reinforced concrete floor slabs. Furthermore, if the floor slabs have larger spans, particularly where the supporting elements are spaced further apart (e.g., 8 meters), then large-span timber elements must be provided, which are difficult to handle or even unavailable. The timber element forming the beam-free floor slab must therefore be constructed from several elements, preferably joined together in two or more planes. The joint pattern between the elements in these at least two planes typically forms a regular connection. At the load transfer points below the floor slab, the elements usually have additional support heads at their upper ends, which may also be made of wood.Furthermore, horizontal load-bearing beams running between the support elements under the floor slab are known as girders, which, however, should also be avoided in order to improve the installation of building services, such as cables and pipes, and especially to enable easier repurposing of a building, thereby further improving its lifespan and thus its CO2 balance.

[0004] From EP 2 787 140 A1, for example, a floor slab in timber-concrete composite construction is known, which allows the proportion of concrete to be reduced, wherein a top slab of the floor slab is made of concrete and a bottom slab of a wood-based material. Spacers are provided between the two slabs, with the top slab and the bottom slab being joined together by means of an adhesive bond.

[0005] EP 2 989 263 B1 discloses a floor slab for a building, in which column heads are arranged on the underside of the load transfer points, allowing the load from the floor slab to be distributed more evenly via the column elements. The column head is to be made of wood, with the objective here, too, of producing wooden floor slabs that allow for large column spacings even in multi-story buildings and that do not require steel or reinforced concrete elements. The technical teaching focuses on the wooden column head with two diverging main grain directions of the wood material, which are to run in the plane of the floor slab. However, the floor elements cannot be designed to be shorter than the spacing of the column elements that ultimately support the floor slab of the building.

[0006] For roof structures, for example, one-dimensional support beams with end supports are known, constructed from several elements, particularly elongated ones, which are glued together. However, it has recently become increasingly apparent that the adhesive strength of glue decreases over time, so that the beam, or so-called truss, can consequently lose its strength. The disposal or reuse of glued timber structures is viewed critically with regard to the widely pursued circular economy. Therefore, the structural element should not only be manufactured without concrete to achieve a good CO2 balance, but it should also be constructed from surface elements that are joined together without adhesives and do not require supporting beams on the underside. REVELATION OF THE INVENTION

[0007] The object of the invention is to further develop a surface body made of surface elements, in particular made of wood, wherein the surface elements individually have smaller dimensions than the entire resulting surface body, i.e. the floor slab, wherein the surface elements are to be advantageously connected to one another in such a way that a high load-bearing capacity is achieved with a low overall height of the surface body.

[0008] This problem is solved starting from a surface body according to the preamble of claim 1 and starting from a method according to the preamble of claim 15 with the respective dependent claims. Advantageous embodiments of the invention are specified in the dependent claims.

[0009] The invention includes the technical teaching that shear-locking means are formed in the surfaces of at least a part of the surface elements between the first plane and the second plane, which prevent slippage by forming a preferably planar positive locking in the contact plane of the overlapping surface elements.

[0010] The core idea of ​​the invention is a preferably and in particular planar form-fit in the surfaces of the surface elements, i.e. in the contact plane of the planar surface elements lying on top of each other, so that the surface elements of the first plane cannot slide off each other in any direction relative to the surface elements of the second plane, without the use of any adhesive or without the use of screw bolts or the like, which would prevent the surface elements from sliding off each other.

[0011] The shear barriers are created by a geometric design of the surfaces of the surface elements, such that they interlock. When the surface elements of the two planes are brought together, the shear barriers can be designed to be complementary with respect to their opposing surfaces. This results in the formation of a surface body with a number of surface elements, where the individual surface elements have smaller main dimensions than the resulting surface body, particularly relevant for a floor slab of a building with large spans, such as 8 meters or more. The surface body in the context of the present invention primarily relates to a floor slab, so the term "surface body" can also be substituted for "floor slab" in this context.

[0012] It has been found that by incorporating just a few shear-locking agents into the surfaces of the panel elements, a highly resilient positive-locking effect is created, resulting in a virtually monolithic or monolithic behavior of the panel structure. This allows a building floor slab to be constructed from a number of panel elements capable of supporting high loads even across larger unsupported areas, provided there is a greater distance between supporting elements below the floor slab. Therefore, the use of adhesives can be dispensed with, eliminating the need to consider aging effects and a decrease in adhesive strength. Wood is particularly suitable as a material for the panel elements, which can, however, also be made of composite materials or plastics, for example.For example, surface elements can also consist of mixed materials, such as wood-plastic composites or mineral wood mixtures. Combinations of these materials are also conceivable to form the surface body, for example, from surface elements made of different materials.

[0013] It is also conceivable that surface elements primarily subjected to compressive loads are made of concrete, a concrete-wood composite, or, more generally, a mineral wood composite. Surface elements of the same body can be made from a combination of concrete-based and wood- or plastic-based materials if they are primarily subjected to tensile loads. It is also conceivable that surface elements are provided from reclaimed concrete elements, for example, from existing stock that have been cut or ground to size. This also avoids the CO2-intensive production of new concrete elements. The same applies to the production of shear barriers, which can also be made from recycled concrete.

[0014] Preferably, the surface elements are made of wood, so that the largest possible proportion of carbon can remain stored in the floor slabs of a building. The effect of a planar interlock is to be understood as follows: the interlock is not limited to a single load-bearing direction, but rather exists in the plane. This plane is referred to here as the planar plane, which results from the contact area between the surface elements of the first and second planes and can be defined by two principal axes.

[0015] The shear locking devices enable the formation of a positive fit between the surfaces by means of linear contact between the surfaces in the planar plane, the contact of which, forming the positive locking effect, has a length-to-width ratio of at least 1:2 and / or at least 1:5 and / or at least 1:10 and / or at least 1:15 and / or 1:20 or more. This linear contact between the surfaces is formed, for example, by means of joints, edges, locking strips, wedges, wedge elements, plates, discs, and the like, which preferably have an elongated extent that creates the length-to-width ratio specified above.Therefore, the invention does not focus on simple bolts for connecting the surface elements of the first level and the surface elements of the second level, since the use of mostly cylindrical pins, bolts, screws and the like creates local shear stress peaks that do not allow the required load-bearing capacity of the surface body, especially not when the surface element forms a floor slab of a building.

[0016] The shear barriers are preferably arranged distributed across the surfaces of the surface elements, preventing the sliding of the surface elements against each other in two axes of the plane of the surface body. The arrangement and design of the shear barriers can be optimized using computer-aided design (CAD) by determining the load situation of the surface body, particularly the floor slab of the building, in order to avoid stress concentrations in the surface elements and especially in the shear barriers. The shear barriers can be designed to achieve the most uniform shear stress possible and optimal force distribution across the surface body through a two-axis load transfer. The two axes in the plane of the surface body are, in particular, perpendicular to each other.This allows the surface elements to be joined together without the need for material bonding agents, particularly because the material bonding effect is achieved through the shear barrier elements. The number of shear barrier elements therefore increases with decreasing distance to the load transfer point.

[0017] Furthermore, connecting elements can still be provided that extend at an angle or, in particular, perpendicularly to the plane of the surface elements and at least partially penetrate both superimposed surface elements, so that the surface elements of the first plane and the surface elements of the second plane are held together by the connecting elements in the thickness direction. The connecting elements can, for example, be made of steel pins or wooden pins that are either screwed in or, preferably, driven into prepared bores in the surface elements in such a way that they remain self-retaining in the surface elements and connect the surface bodies to each other in their thickness direction. However, the connecting elements do not bear any load in the horizontal direction in the plane of the surface, even if they could act as small shear barriers, as they serve only to secure the surface elements to one another.As already explained above in connection with the ratio of length to width of the contact area of ​​the surfaces in the planar plane to each other, a positive locking mechanism required according to the invention cannot be provided, since stress peaks arise with screws or pin elements that would limit the load-bearing capacity of the surface body.

[0018] The surface body has, in particular, load transfer points under which the support elements can be arranged, with the shear restraints having a path aligned with the load transfer points. Especially high stresses and shear forces arise at the load transfer points between the at least two planes in the surface body, since an external force is introduced into the surface body at these points, for example, by support elements. The load introduced at the load transfer point is distributed throughout the surface body, so that the path of the shear restraints can advantageously be aligned with the load distribution originating from the load transfer point. For example, the shear restraints can encircle the load transfer points in a ring or polygon shape, or they can be locally confined, for example, arranged in an island-like fashion around the load transfer points.If the shear barrier means have a longitudinal extension and thus form barrier edges, the course of the barrier edges can be aligned in such a way that the shear stresses occurring between the surface bodies in the first plane and in the second plane are oriented perpendicular to the course of the barrier edges.

[0019] According to a first embodiment, the shear locking devices can have locking strips, with grooves being provided in the surfaces of the surface elements. The locking strips fit into these grooves, creating a positive fit in the planar plane of the surface elements. For example, the locking strips project with one side into the grooves of the first surface elements and with a second side into the grooves of the second surface elements, thereby also creating locking edges at the edges of the grooves that transfer the shear stress against the locking strips. A polygonal enclosure of the load transfer points is advantageous if the locking strips can be provided more easily as straight elements compared to arcuate locking strips.However, it is also conceivable that the locking strips have a rectangular shape, even a polygonal shape, a circular disk shape, a plate shape or a star shape, so that the grooves in the surface elements are designed to complement this.

[0020] The locking strips can therefore also form disc elements, flat cylinders, ovals, star shapes, plate elements and the like in an elongated shape, which are also distributed at points between the surfaces of the overlapping surface elements in complementary recesses of both surfaces, the recesses forming the aforementioned grooves.

[0021] Alternatively or additionally to the insertion of locking strips into designated grooves in the surfaces of the surface elements, the shear barriers can also be formed, for example, by means of a contour topography in the surfaces of the surface elements. Contour edges or surfaces can also be formed with a contour topography, which can act as a barrier against shear stresses in the planar plane of the surface bodies. The contour topography is located in the surfaces of the surface elements of the first and second planes, with the respective opposing contour topography being complementary to the second contour topography. If the contour topography has a raised area on the surface in one region, the surface of the opposing surface element has a complementary depression.The topographic features can also form around the load transfer points, and these features can have one or more elevation levels where the barrier edges are formed, or the barrier edges define the boundaries of these elevation levels. The barrier edges define barrier surfaces that run perpendicular to the planar extension plane of the overlapping surfaces of the surface elements.

[0022] The height planes can also be distributed concentrically, annularly, or polygonally around the load transfer points, thus enabling the principle of creating locking edges on the surfaces of the overlapping surface bodies. In this way, the height planes can be bounded by locking edges which, due to the complementary height topographies between the surface elements, create a positive fit in the planar plane of the surface elements.

[0023] The shear locking devices can have a height corresponding to 2% to 30%, 5% to 25%, or 10% to 20% of the thickness of the surface body. For example, the height of the shear locking devices can be determined by the height of the locking strips or twice the depth of the associated grooves. Alternatively, the height of the shear locking devices can be determined by the maximum height difference of the topography, in particular between the elevation levels.

[0024] The surface elements are butted together in each of the two planes to form the surface body. This butt joint of the surface elements creates a joint with a joint profile that is offset between the surface elements of the first plane and the surface elements of the second plane, or runs perpendicular to each other, whereby an angle of less than 90° or a zigzag profile is also quite conceivable. The joint profile of the butt joint of the surface elements, and thus the joint itself, can be independent of the path of the shear barriers. The shear barriers can therefore also intersect the joint profile or run parallel to it without impairing their shear barrier effect.

[0025] The invention further relates to a method for producing a planar body, in particular a floor slab of a building, comprising several planar elements, wherein the method comprises at least the following steps: introducing shear-locking means into the surfaces of at least a part of the planar elements between the first plane and the second plane; arranging the planar elements in the first plane and in the second plane forming a planar interlock between the planar elements in the two planes by means of the shear-locking means, so that sliding of the planar elements against each other is prevented and the planar body acquires monolith-like properties. PREFERRED EXAMPLE OF THE INVENTION

[0026] Further measures improving the invention are described in more detail below, together with a description of a preferred embodiment of the invention, with reference to the figures. The figures show: Fig. 1 a perspective, schematic view of two surface bodies with supporting elements arranged between them, the surface bodies forming respective floor slabs of a building; Fig. 2 a sectional view through a surface body with a number of surface elements arranged in two planes and between which shear locking means are placed, formed by locking strips; Fig. 3 a cross-sectional view of a surface body according to Fig. 1, where, for example, in Fig. 2 the shear barrier means are formed by a height topography in the surfaces between the surface elements; Fig. 4 an exploded view of a surface body with several surface elements, wherein the shear locking means are formed with locking strips and Fig. 5 a view of two planes of surface elements with shear barriers formed by a height topography.

[0027] Fig. Figure 1 shows schematically and in perspective view two floor slabs 1 of a building, which are formed by corresponding surface bodies 1. Several support elements 15 extend between the superimposed surface bodies 1.

[0028] The surface bodies 1 or floor slabs 1 are constructed from a plurality of surface elements 10, which are joined together at the joints, forming corresponding joints 21. The surface elements 10 extend in a first plane E1 and in a second plane E2 below, with the respective joints 21 between the surface elements 10 in the two planes E1 and E2 being offset from one another. The surface elements 10 have smaller main dimensions than the main dimensions of the surface body 1, so that free spans between the support elements 10 can be achieved with smaller surface elements 10. For example, the distance between the support elements 15 can be 6 m to 8 m, whereas the length of the surface elements 10 is, for example, 1 m or 3 m in the main dimension.

[0029] The Fig. 2 and Fig. Figure 3 shows a cross-section through the surface bodies 1 with surface elements 10, which are arranged one above the other in the two planes E1 and E2 and are joined at the joints 21. Support elements 15 are also indicated below the surface bodies 1.

[0030] Between the surface elements 10 of the first plane E1 and the second plane E2, shear barriers 12 are formed that prevent planar sliding of the surface elements 10 against each other. Planar sliding refers to a relative movement of the surface elements 10 in their plane of extension relative to each other, in particular in the joint between the two planes E1 and E2. The shear barriers 12 are designed such that they create a shear barrier in this plane, and thus in their entire planar, surface extension, at least in at least two axes that are perpendicular to each other.

[0031] To enable the surface elements 10 to be held together, connecting means 13 are provided, which can be formed, for example, from steel pins or wooden pins, and which are inserted, in particular pressed, into corresponding bores in the surface elements 10.

[0032] The exemplary embodiment according to Fig. Figure 2 shows shear locking means 12 in the form of locking strips 16, which are inserted into associated grooves 17 in the surfaces 11 of the surface elements 10. The exemplary embodiment shows at least two different directions of extension of the locking strips 16, namely in the section plane and perpendicular to the section plane. This makes it clear that the shear locking means 12 provide not only a unidirectional, but also a planar effect of a positive locking.

[0033] According to the embodiment in Fig. 3. The shear locking means 12 are formed via a height topography 18, such that the surfaces 11 of the surface elements 10 interlock via the height topography 18. The height topography 18 is shown with a profile that is only to be understood as an example, but the respective interlocking by forming locking edges 20 can be understood from the profile. The locking edges 20 formed prevent the two surfaces 11 of the surface elements 10 from sliding relative to each other in the plane.

[0034] Fig. Figure 4 shows an exploded view of the surface body 1 with a number of surface elements 10, wherein the shear locking devices 12 are formed with locking strips 16 that are inserted into corresponding grooves 17 in the surfaces 11. The flying view of the exploded view thus shows the locking strips 16, which are geometrically adapted so that they can be inserted precisely into the grooves 17. The grooves 17 can, for example, have a depth corresponding to half the height of the locking strips 16, so that the locking strips 16 can engage halfway into a groove 17 in surface elements 10 of the first plane E1 and with the other half into a groove 17 of the surface elements 10 in the second plane E2. In this way, an interlocking connection is formed, by which the shear locking devices 12 are created and act in the planar plane between the surface elements 10.

[0035] The illustration shows that the shear barriers 12 are designed specifically around the load transfer points 14 in the surface body 10. This allows the high shear forces at the support points, resulting from the load transfer, to be transmitted, so that the geometric design of the shear barriers 12, in this case the arrangement of the barrier strips 16, ensures a load introduction into the surface body 1 as required, without resulting in excessive load distribution. The joint profile 22 between the surface elements 10 of the first level E1 and the second level E2 is perpendicular to each other and is independent of the profile of the shear barriers 12.

[0036] Fig. Figure 5 shows an alternative embodiment for forming the shear barriers 12 between the surface elements 10 of the surface body 1. The surface elements 10 of the respective planes E1 and E2 are shown unfolded, with the surface elements 10 from plane E1 being unfolded onto the surface elements 10 of plane E2 to complete the surface body 1. The height topography 18 is formed by several cascading height levels 19, each bounded by a respective barrier edge 20. For example, the height topography 18 on the surface elements 10 in the first plane E1 shows respective elevations that protrude from the surface, and the height topography 18 of the surface elements 10 in the second plane E2 shows depressions that are complementary to the elevations.When the surface elements 10 from the two planes E1 and E2 are brought together, the height planes 19 of the surface elements 10 of plane E1 engage in the recesses of the height planes 19 of the surface elements 10 of the second plane E2. The respective locking edges 20 of the height planes 19 consequently form an interlocking, as is also the case in . Fig. 3 is already visible.

[0037] The surface elements 10 have a joint profile 21 relative to each other, which is designed such that it differs between the two planes E1 and E2, in particular being approximately perpendicular to each other. The orientation of the joints 21, rotated approximately 90° in each case, also corresponds to the representation according to Fig. 4, in which the joint line 22 of the surface elements 10 of the first level E1 and the second level E2 is perpendicular to each other.

[0038] The invention is not limited in its implementation to the preferred embodiment described above. Rather, a number of variants are conceivable, which utilize the solution presented even in fundamentally different designs. All features and / or advantages arising from the claims, the description, or the drawings, including design details or spatial arrangements, can be essential to the invention, both individually and in various combinations. Reference symbol list: 1. Surface body, floor slab 10 surface elements 11 Surface 12 thrust restraint devices 13 Connecting agents 14 Load transfer point 15 support elements 16 Locking strip 17 Nut 18 Elevation topography 19th level 20 locking edge 21 joint 22 Joint pattern E1 first level E2 second level QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 2 787 140 A1

[0004] EP 2 989 263 B1

[0005]

Claims

[1] Surface body (1), in particular floor slab (1) of a building, comprising several surface elements (10) which are arranged adjacent to one another in a first level (E1) and at least a second level (E2), characterized by , that in the surfaces (11) at least a part of the surface elements (10) between the first plane (E1) and the second plane (E2) shear locking means (12) are formed which prevent the surface elements (10) from sliding against each other by forming a preferably planar positive locking. [2] Planar body (1) according to claim 1, characterized by , that the shear locking means (12) are arranged distributed over the surfaces (11) of the surface elements (10) so that the sliding of the surface elements (10) against each other in the two axes of the extension plane of the surface body (1) is prevented. [3] Planar body (1) according to claim 1 or 2, characterized by, that the shear locking means (12) form a linear contact for the formation of the positive locking between the surfaces (11) which has a length-to-width ratio of at least 1:2 and / or at least 1:5 and / or at least 1:10 and / or at least 1:15 and / or at least 1:

20. [4] Planar body (1) according to any one of claims 1 to 3, characterized by , that connecting means (13) are provided, wherein the surface elements (10) of the first level (E1) and the surface elements (10) of the second level (E2) are connected by the connecting means (13). [5] Planar body (1) according to any of the preceding claims, characterized by , that the surface body (1) has load transfer points (14) which can be arranged under the support elements (15), wherein the shear barrier means (12) have a profile which is aligned with the load transfer points (14). [6] Planar body (1) according to any of the preceding claims, characterized bythat the shear barriers (12) at least partially enclose the load transfer points (14) in a ring-shaped or polygonal shape along their course. [7] Planar body (1) according to any of the preceding claims, characterized by , that the shear locking means (12) have locking strips (16), wherein grooves (17) are provided in the surfaces (11) of the surface elements (10) in which the locking strips (16) are inserted and create the positive locking in the planar plane of the surface elements (10). [8] Planar body (1) according to any of the preceding claims, characterized by , that the shear barrier means (12) are formed by means of a height topography (18) in the surfaces (11) of the surface elements (10), wherein the height topography (18) in the surfaces (11) of the surface elements (10) of the first level (E1) is complementary to the height topography (18) in the surfaces (11) of the surface elements (10) of the second level (E2). [9] Planar body (1) according to claim 8, characterized by, that the height topography (18) in the surfaces (11) of the surface elements (10) has at least one or more height levels (19). [10] Plane body (1) according to claim 9, characterized by , that the height planes (19) are bounded by means of barrier edges (20) which, due to the complementary height topographies (18) formed between the surface elements (10), create the form fit in the planar plane of the surface elements (10). [11] Planar body (1) according to any of the preceding claims, characterized by , that the surface elements (10) are made of wood, of a wood-plastic composite or of a mineral wood mixture or a combination thereof, in particular by combining several surface elements (10) made of different materials to form a surface body (1). [12] Planar body (1) according to any of the preceding claims, characterized by, that the shear locking means (12) have a height in their geometric design which corresponds to 2% to 30% and / or 5% to 25% and / or 10% to 20% of the thickness of the surface body (1). [13] Planar body (1) according to any of the preceding claims, characterized by , that the joints (21) between the surface elements (10) form a joint profile (22) which is offset from each other and / or perpendicular to each other between the surface elements (10) of the first level (E1) and the surface elements (10) of the second level (E2). [14] Planar body (1) according to any of the preceding claims, characterized by , that the joint of the surface elements (10) against each other forms a joint profile (21) which is independent of the profile of the shear barrier means (12). [15] Method for producing a planar body (1), in particular a floor slab of a building, comprising several planar elements (10), wherein the method comprises at least the following steps: - Introducing shear barrier devices (12) into the surfaces (11) of at least part of the surface elements (10) between the first plane (E1) and the second plane (E2), - Arranging the surface elements (10) in the first plane (E1) and in the second plane (E2) forming a planar positive fit between the surface elements (10) in the two planes (E1, E2) by means of the shear locking means (12), and - Preventing the surface elements (10) from sliding against each other and forming monolith-like properties of the surface bodies (1).

Images