METHOD FOR PRODUCING A COMPOSITE ELEMENT AND COMPOSITE ELEMENT

Description

[0001] The invention relates to a method for producing a composite element.

[0002] Furthermore, the invention relates to a composite element comprising a first element with a recess and at least one second element connected to the first element, which second element comprises a hardened material and a reinforcement.

[0003] Various methods for producing composite elements, as well as composite elements of the type mentioned above, have become known from the prior art. Such composite elements are used, for example, in building construction to connect elements made of different materials, such as wooden elements with concrete elements. The disadvantage of such composite elements is that they always require concreting on site, which, on the one hand, makes industrial production like that of a prefabricated house impossible. On the other hand, concreting on site is also associated with considerable time and expense.

[0004] FR 2 780 427 A1 discloses a method according to the preamble of claim 1 and a composite element according to the preamble of claim 7.

[0005] This is where the invention comes in. The object of the invention is to provide a method of the type mentioned above that can be implemented particularly efficiently.

[0006] Furthermore, an efficiently manufactured composite element of the type mentioned above is to be specified which has a high load-bearing capacity.

[0007] The first object is achieved according to the invention by a method according to independent claim 1, in which a first element is provided with a recess, after which a reinforcement partially projecting from the recess is positioned in the recess, after which the recess is filled with hardenable material, in particular concrete, after which the hardenable material hardens in the recess to form a second element, so that the reinforcement is positively connected to the first element via the hardened material.

[0008] With the method according to the invention, a connection between the first element and the second element can also be made in advance, for example in a prefabricated component factory, so that industrial production of the composite element is possible. A connection of the composite element with other components of a building on a

[0009] The reinforcement can be installed on the construction site via the reinforcement protruding from the recess. A composite element manufactured according to the invention thus comprises a first element with a recess and a second element comprising a hardened material and reinforcement, usually made of steel. The first element and the second element are positively connected via the recess.

[0010] To ensure good force transmission, it is advantageous to fill the recess with a shrinkage-compensated, hardenable material, especially shrinkage-compensated concrete. This ensures a positive fit for force transmission even during hardening.

[0011] It is envisaged that a first element is provided with a recess, which recess extends essentially along a longitudinal direction and has a cross-section that varies along the longitudinal direction and has arrow-shaped shear cams. The usually plate-shaped element can then be connected to the reinforcement in a shear-resistant manner along the longitudinal direction by the hardened material. This means that the composite element can be advantageously used in particular as a ceiling element, especially since the element, which is usually made of wood, can absorb the tensile forces in a lower region of the composite element in the event of deflection and a concrete beam, a concrete slab or the like that is connected to the first element in a shear-resistant manner via the reinforcement can absorb compressive forces in an upper region of the composite element. This results in a lightweight yet load-bearing composite element for forming ceiling elements in buildings.

[0012] It has proven useful to position a displacement body, preferably a filling material, a hollow body and / or formwork, on the first element adjacent to the recess, after which hardenable material, in particular fiber concrete, preferably micro-fiber concrete, is applied to the part of the reinforcement protruding from the recess, such that the reinforcement is essentially enclosed in the hardenable material. This makes it easy to form a structural element for a building with a hollow space enclosed between the hardened material and the first element. The hollow space can be used, for example, to accommodate cables and the like. Alternatively, the displacement body can also be a thermally insulating material, thus achieving a thermally insulating and simultaneously stable structural element. Furthermore, the displacement body itself can be a load-bearing structural element, for example a reinforced concrete element.In this case, the method according to the invention provides a stable connection between the reinforced concrete element and the composite element in a simple manner.

[0013] It is advantageous if the curable material is applied in such a way that, after the curing of the curable material, the displacement body is fixed relative to the first element. This enables a particularly advantageous combination of a prefabricated composite element with a wide variety of displacement bodies, allowing the creation of a wide variety of components.

[0014] The material used to fill the recess can be the same as the material used to enclose the reinforcement; however, different materials can also be used, such as concrete of different grades. Furthermore, the material used to enclose the reinforcement can be applied immediately after filling the recess or at a later time, for example, on a construction site as cast-in-place concrete.

[0015] It is advantageous if the first element has several parallel recesses, in each of which a reinforcement is positively connected to the first element via a hardenable material. This easily creates a composite element that exhibits high strength beyond the hardened material typically made of concrete, even if the first element is not made of a high-strength material. Because the stability or strength of the composite element can be achieved through the hardened material, the first element can also be made of a material of lower strength, such as wood, plastic, or the like.As a result, the method according to the invention can be used to form load-bearing components for buildings which, on the one hand, can have an attractive exterior due to the first element, and, on the other hand, also ensure high strength and stability thanks to the cured material, which is usually made of concrete. For example, a building ceiling can be easily formed in this way, which consists exclusively of wood or the like on a visible underside and which is positively connected to a second element formed as a reinforced concrete beam by the reinforcement and the cured material. Such a wood-concrete ceiling can be completely prefabricated, thus eliminating the need to construct formwork on a construction site.The method according to the invention thus forms a wood-concrete composite element which can be produced significantly more cost-effectively, reliably and quickly than with prior art methods.

[0016] A composite element constructed according to the invention can be used in a variety of ways. Use of the composite element formed by the method according to the invention, particularly as a ceiling in a building, is particularly advantageous if a first element is used with a recess having a cross-section configured such that a positive connection of the cured material to the first element can be subjected to a tensile force perpendicular to a surface of the first element in which the recess is located.In this way, for example, a wooden ceiling supported by reinforced concrete girders can be easily achieved. The first element, designed as a wooden ceiling and arranged on the underside of the composite element, is supported by the second element, designed as a reinforced concrete girder and positioned on a non-visible upper side, via a form-fit connection created by the cross-section. Stability is ensured even if the cured material shrinks slightly during curing. This type of recess cross-section can be achieved in a variety of ways. Typically, a dovetail-shaped cross-section is used.

[0017] It is advantageous if the first element is formed by providing at least two sub-elements which are connected to the first element, wherein the sub-elements are connected in particular via a connecting element, preferably a mandrel, which is connected at a first end to a first sub-element and at a second end to a second sub-element and extends through the recess. After the first element has been formed in this way, a reinforcement is then positioned in the recess, usually adjacent to the mandrel, and the recess is filled with the hardenable material. The hardenable material encloses the mandrel and thus, upon hardening, forms a connection with the first element via the mandrel, which connection has a high shear strength. A connection between the mandrel and the first element orThe sub-elements forming the first element can be connected by a positive connection, for example, by drilling holes into the sub-elements into which the mandrel extends. The sub-elements can also be connected only via the mandrel, so that the sub-elements are spaced apart by the recess.

[0018] The mandrel, which can also be referred to as a shear mandrel, ensures a load-bearing connection between the first element and the hardened material, both in a longitudinal direction and vertically or perpendicular to the longitudinal direction of the recess.

[0019] Although the connecting element is preferably designed as a mandrel with a roughly circular cross-section and a diameter of approximately 10 mm to 20 mm, the connecting element can of course also have other shapes and cross-sections to form a multi-directional load-bearing connection between the first element and the cured material. Typically, the connecting element partially protrudes into the recess, is fixed in the first element, and is made of a material with greater strength than the material of the first element or greater strength than wood. The connecting element is preferably made of a metal or a fiber composite material.

[0020] The method according to the invention can be implemented industrially with a high degree of automation, for example, in a precast concrete plant. Therefore, it is advantageous to use a composite element produced using a method according to the invention in a process for manufacturing a building in order to achieve advantageous and process-reliable production.

[0021] The composite element can be connected to other components of a housing in a variety of ways. A high level of flexibility with regard to different application and connection options is easily achieved if the recess in a precast concrete plant is filled with hardenable material in a first step, which hardens in the recess, after which the composite element is transported to a construction site and arranged adjacent to other components. After that, in a second step, further hardenable material is applied to a part of the reinforcement protruding from the recess, so that when this hardenable material hardens, the composite element is connected to the other components via the second hardenable material. Concrete is generally used as the hardenable material. Concrete applied on site is also known as in-situ concrete or cast-in-place concrete.also referred to as topping concrete when the concrete in the second step is applied to concrete placed in the recess in the first step.

[0022] In this process, on the one hand, hardenable material is introduced into the recess at the factory or in advance to connect the reinforcement to the first element. On the construction site, the reinforcement protruding from the recess is connected to other components of the building using additional hardened material. The hardenable material that is introduced into the recess at the factory can be the same as that used on the construction site. However, different hardening materials can also be used. Connection to other components on the construction site can be made using reinforcement that is connected to the reinforcement of the second element using hardenable material introduced at the construction site, usually in-situ concrete. Furthermore, the connection can be made by means of a form fit using the in-situ concrete or topping concrete.

[0023] Alternatively, the building can be constructed without concreting on site if all hardenable material is applied in advance, for example, in a precast plant. Afterward, the composite element is transported to a construction site where it is joined to other building components essentially without the use of a water-based building material. This enables the construction of a building in which composite elements designed according to the invention, for example as wood-concrete composite elements, are provided using a dry construction process, which can thus be implemented particularly quickly and regardless of weather conditions.

[0024] The further object is achieved by a composite element according to independent claim 7, in which the at least one second element protrudes at least partially from a recess of the first element and is positively connected to the first element in the recess, wherein the composite element is produced in particular using a method according to the invention.

[0025] The positive connection between the first element and the second element, which is made of a cured material, enables cost-effective and reliable prefabrication of the composite element, for example, in a precast plant. At the same time, the composite element is highly rigid and has an attractive appearance, even if the first element is not made of a high-strength material. The recess typically has a constant cross-section in the first element, extending along a straight line.

[0026] Typically, a cross-section of the recess is designed such that a positive connection between the cured material and the first element can be loaded with a tensile force perpendicular to a surface of the first element in which the recess is located. For example, the composite element can be advantageously used to form ceilings of a building if the composite element comprises a visually appealing first element of low strength and a load-bearing second element of high strength. This makes it particularly easy to form a wooden ceiling supported by one or more reinforced concrete beams.

[0027] Such a cross-section can be designed in a variety of ways. Typically, a cross-section capable of withstanding tensile force can be easily achieved if the distance between the side surfaces of a cross-section of the recess increases, at least in some areas, with increasing distance from a surface in which the recess is located. This ensures positive force transmission even if the cured material shrinks slightly, for example, during curing.

[0028] Simple and reliable production of the recess is possible if the recess has a dovetail cross-section. If the first element is made of wood, plastic, or similar, for example, the recess can then be easily and automatically formed with high precision using milling.

[0029] It has proven useful for the first element to consist essentially of wood, in particular of several cross-glued single-layer boards. Wood has proven advantageous in buildings because this material can be used to achieve an attractive appearance and a pleasant indoor climate. Until now, the formation of a wooden ceiling in a building with load-bearing reinforced concrete girders was only possible with great effort and expense, by subsequently attaching or suspending a wooden intermediate ceiling onto a concrete ceiling. In contrast, with a composite element according to the invention, a wooden ceiling can be formed at the same time as a load-bearing part of the building, by designing the composite elements according to the invention with a first element designed as a wooden ceiling and second elements designed as reinforced concrete girders. The second elements are usually elongated orin the form of a beam and with an approximately constant cross-section along a longitudinal extent.

[0030] The first element may in particular contain one or more of the materials solid wood, glued laminated timber, board stacked timber, laminated veneer lumber, veneer plywood, construction beech, single- or multi-layer OSB boards, in particular Magnum Board, or consist of one of these materials.

[0031] Due to the form-fitting connection between the timber floor and the reinforced concrete beam, the timber floor can also assume a load-bearing function, thus reducing the strength of the reinforced concrete beam. Furthermore, in-situ concrete poured on site can also have a load-bearing effect and contribute to the building's strength. This, in turn, results in reduced weight and thus lower material costs. Particularly when the first element comprises several cross-laminated single-layer panels or is constructed as a cross-laminated timber panel, the first element can achieve both an attractive appearance and make a certain contribution to the overall load-bearing capacity of the composite element.

[0032] To achieve high strength and stability, it has proven advantageous to design the reinforcement as a lattice girder, with two lower chords and one upper chord, and the lower chords positioned in the recess. This makes it easy to achieve a high area moment of inertia and thus high strength and stiffness of the second element or the entire composite element.

[0033] According to the invention, the recess has a cross-section that varies along its length. This creates a so-called shear cam made of hardened material in the recess, which creates a positive connection in the longitudinal direction with the first element, thus also enabling the transmission of forces in the longitudinal direction. This creates a connection between the first element or wood and the hardened material or concrete with high shear strength or high flexural rigidity and strength. Such composite elements can be advantageously used particularly for lightweight components that bridge large spans with low deflection, for example, ceilings of halls or the like.

[0034] Typically, the recess is elongated and closed off at the sides. This ensures ease of manufacture. It also allows, for example, several recesses to be arranged roughly parallel in a composite element, which can be filled sequentially without curable material flowing from one recess into an adjacent one.

[0035] A cross-section that is discontinuous over a length of a usually elongated and laterally closed recess can be formed in a variety of ways. According to the invention, the recess is designed, at least in some regions, with tapered side edges in plan view to enable particularly good transmission of thrust forces. This results in arrow-shaped thrust cams. In this context, it is advantageous if at least two arrow-shaped thrust cams are provided and arranged in opposite directions in the recess to ensure good transmission of forces in the longitudinal direction. Rectangular or round thrust cams can also be provided to enable good transmission of forces in the longitudinal direction. Typically, two to ten thrust cams are provided along the length of the recess.

[0036] Advantageously, the recess extends over a large part of the length of the composite element, preferably over more than 70%, in particular more than 80%, of the length of the composite element. Typically, the recess extends substantially over the entire length of the composite element. Normally, the recess runs approximately along a straight line.

[0037] It is advantageous if the reinforcement has two bottom chords positioned in the recess, with the distance between the bottom chords not being constant along the length of the recess. The bottom chords can then have a distance from each other that, in the case of a recess formed along a longitudinal direction with a discontinuous cross-section, increases and decreases almost synchronously. This creates a particularly shear-resistant connection between the cured material and the recess.

[0038] In particular, it can be provided that the distance between the bottom chords is, at least in some areas, greater than a minimum distance from the side edges of the recess. This simply ensures that hardened material in the recess cannot be displaced along the recess, thus ensuring a shear-resistant connection.

[0039] It has proven effective for the lower chords to be at an angle to each other, at least in some areas, in a plan view, in particular at an angle of 1 degree to 170 degrees, preferably 10 degrees to 45 degrees. The lower chords can then be designed, in particular, with corresponding shear cams, so that the distance between the side edges of the recess and the lower chord closest to the respective side edge can be approximately constant. This ensures high bending strength with low weight.

[0040] Furthermore, in order to achieve a high flexural rigidity or a particularly shear-resistant connection, it is provided that the recess has wider and narrower regions, namely shear cams, along a longitudinal direction, wherein a metal part connected to the reinforcement and formed by a steel stirrup is provided in the recess, which extends into the wider regions.

[0041] According to the invention, it is provided that the metal part at least partially follows a contour of a side edge of the recess, namely is partially approximately parallel to the side edge of the recess.

[0042] Furthermore, it is provided that a steel stirrup is positioned in the recess, which is aligned at least in some areas at an angle of 45 degrees to 135 degrees, in particular 80 degrees to 100 degrees, to a longitudinal direction of the recess and is connected to the lower chords of the reinforcement. The steel stirrup can thus, in particular, ensure a spacing between the lower chords, so that a local widening of the lower chords or a locally larger spacing between the lower chords can be mechanically stabilized by means of the steel stirrup.

[0043] To achieve high shear strength, it is advantageous if a connecting element, in particular a mandrel, is rigidly connected to the first element, which partially projects into the recess. The connecting element is preferably connected to the first element on two sides and is surrounded by the cured material in the recess. Typically, the connecting element, designed as a mandrel, is positively connected to both the first element and the cured material. The cured material is thus positively connected to the first element via the mandrel, both longitudinally for the transmission of shear forces and vertically.If, for example, the first element is constructed as a wooden element and the cured material is constructed as a concrete beam above the wooden element, this creates a load-bearing connection in the vertical direction, with the wooden element being supported by the concrete beam via the dowel, and a composite element with high shear strength and flexural rigidity, as both the wooden element and the concrete beam contribute to the rigidity. This makes the composite element particularly suitable for large spans or as a self-supporting component. Typically, the dowel extends through the recess and is connected to the first element at its ends on opposite sides of the recess, usually with a positive fit.

[0044] The reinforcement can be designed in a variety of ways, for example, as a metal element, particularly as a steel element. To create lightweight components and components in a wide variety of shapes, it is advantageous for the reinforcement to be designed as textile reinforcement, particularly with glass or carbon fibers. In particular, the reinforcement can be designed as a lattice-like textile reinforcement to achieve high strength with low weight. Such textile reinforcement is generally thin and flexible, allowing even small and / or twisted composite elements with a narrow recess to be produced.

[0045] The cured material can, in principle, be formed in a variety of ways. For use of the composite element in buildings, it has proven particularly effective to achieve high stability if the cured material consists primarily of concrete, especially fiber-reinforced concrete, preferably micro-fiber-reinforced concrete.

[0046] In order to construct a flat element as a composite element according to the invention during the construction of a building, it has proven advantageous to connect a plurality of second elements to the first element, wherein the second elements are connected to the first element via a plurality of recesses. The plurality of second elements then achieves a high degree of rigidity and strength of the composite element. The first element can be designed as a visually appealing element with low strength, for example, as a wooden ceiling or the like.

[0047] To achieve the most even stress distribution possible in the composite element, it is advantageous if the recesses are approximately parallel and preferably regularly spaced. This easily prevents uneven deformation.

[0048] A composite element according to the invention can be manufactured industrially, thus cost-effectively and with high process reliability. Therefore, in a building with a composite element, it is advantageous if the composite element is designed according to the invention.

[0049] As stated, the composite element according to the invention can be easily designed such that the first element is visually appealing and of low strength, while the required strength and rigidity are provided by the second element, which essentially supports the first element. It is therefore advantageous if the first element forms a ceiling of an interior space, which is essentially supported by at least one second element. Typically, the first element is then formed from wood, preferably from cross-laminated timber, in particular from cross-laminated single-layer panels. In this case, the cross-laminated single-layer panels can also contribute to the stability of the building, although this is not required.

[0050] Typically, the second element is positioned above the first element. The second element is typically designed as a load-bearing element, usually made of reinforced concrete. The first element is thus supported by the second element via the form fit or suspended from a building support formed by the second element.

[0051] A cost-effective and stable construction is possible if the at least one second element is designed, for example, in the form of an I-beam. This makes it easy to construct a building in which load-bearing elements are formed by reinforced concrete components such as reinforced concrete beams, with a wooden ceiling suspended from the reinforced concrete beams of a ceiling at a lower end, forming a first element of a composite element according to the invention.

[0052] To achieve particularly high strength and stability, at least one second element can contain a steel girder. Depending on the required strength, reinforcement such as a lattice girder encased in the concrete of the second element may also be sufficient.

[0053] It has proven useful for the second element to be connected to the first element at a lower end and to a floor of a storey above at an upper end. The second element usually forms a reinforced concrete beam, from which a ceiling of a room below hangs or is connected via a form fit, and on which a floor of a room above is positioned at the top. If the second element is designed as an L-shaped beam, for example, a space between the second element can be used for a thermally insulating material or for routing cables, for example installation lines. Furthermore, the preferably elongated second elements, which are designed as beams, can have openings arranged perpendicular to a longitudinal extent of the same, through which openings cables can be routed.Unlike conventional screed, this type of construction allows for the subsequent installation of cables or the provision of outlets in a floor. This is not possible with conventional screed. Instead, the positions of cables and the like that emerge from the floor must be definitively determined in advance, meaning that the cable routing must also be determined in advance. Therefore, a construction method according to the invention achieves increased flexibility, particularly after the completion of a building.

[0054] To dampen vibrations and reduce sound transmission between floors, the second element is usually connected to the floor using an elastic adhesive.

[0055] It is advantageous if pipes are positioned in the second element to enable heating or cooling of the building through the composite element. The pipes can also be pre-arranged in the second element during the production of the composite element, thus enabling the creation of underfloor heating and / or cooling at very low cost and with high process reliability.

[0056] A stable construction of the building is easily achieved if the second element is designed as a beam which is supported at the ends, preferably by side walls.

[0057] The side walls can generally be constructed from a variety of materials, such as brick or concrete. However, it can also be provided that the composite element is supported on side walls that consist primarily of wood, in particular of several cross-laminated single-layer panels. By using wood or cross-laminated timber panels, a building with wooden walls and a wooden ceiling and walls can be easily constructed. Due to the use of reinforced concrete, this building is highly stable, can be manufactured cost-effectively and reliably, and has an attractive appearance.

[0058] Further features, advantages, and effects of the invention will become apparent from the following exemplary embodiment. Reference is made to the drawings, which show: Fig. 1 a first embodiment of a composite element not according to the invention Fig. 2 a part of a floor of a building with a composite element according to Fig. 1 ; Fig. 3 another composite element not according to the invention; Fig. 4 . a floor of a building with a composite element according to Fig. 3 ; Fig. 5 bis 8 further composite elements not according to the invention; Fig. 9 bis 11 Sections from ceilings of buildings with composite elements not according to the invention; Fig. 12 bis 15 various sections through support areas of building ceilings with composite elements not according to the invention; Fig. 16 bis 20 further composite elements not according to the invention; Fig. 21 a detail of a composite element according to the invention

[0059] Fig. 1 shows a composite element 1 not according to the invention in a sectional view. Fig. 1 In the embodiment shown, a first element 2 is formed by a cross-laminated timber panel 14, which has five cross-glued single-layer wooden panels. As can be seen, a recess 5 is provided in the panel-shaped first element 2, wherein a cross-section of the recess 5 has side surfaces 19 in an upper region, which have an increasing distance from one another with increasing distance from a surface 10 in which the recess 5 is arranged. Such a cross-section is also called a dovetail cross-section and is generally introduced into the first element 2 by milling. A lattice girder 6 protruding from the recess 5 is fixed in the recess 5 by means of concrete 4 as a hardenable material. The lattice girder 6 has two lower chords 12 and an upper chord 11.

[0060] The Fig. 1 The composite element 1 shown can be manufactured entirely in-house or in a precast concrete plant in an automated manner and with a high level of process reliability. For this purpose, a corresponding recess 5 is milled into the cross-laminated timber panel 14 or the first element 2, after which the lattice girder 6 is positioned in the recess 5 and the recess 5 is filled with concrete 4 in order to fix the lattice girder 6 in the recess 5. Due to the dovetail-shaped cross-section of the recess 5, a positive connection is created between the second element 3 formed by the concrete 4 and the lattice girder 6 and the first element 2, which can also be loaded by a tensile force perpendicular to the surface 10. As a result, the composite element 1 according to the invention can be used, for example, to form a ceiling 13 if the second element 3 is supported at the end so that the first element 2 hangs from the second element 3.

[0061] Fig. 2 shows a section of a ceiling 13 of a building, which is covered with a Fig. 1 illustrated composite element 1. As can be seen, the cross-laminated timber panel 14 forms a wooden ceiling in which several approximately parallel and regularly spaced dovetail-shaped recesses 5 are positioned. A lattice girder 6 is arranged in each of the dovetail-shaped recesses 5 and is positively connected to the cross-laminated timber panel 14 via concrete 4. The lattice girders 6 with the concrete 4 arranged in the recesses 5 thus form supports to which the cross-laminated timber panel 14 is fastened via the dovetail cross-section. Displacement bodies 30, which are U-shaped in cross-section and designed as prefabricated concrete elements 9, are positioned between the girders or the second elements 3. The displacement bodies 30 serve as a support surface for a floor 16 of a room arranged above. At the same time, the displacement bodies 30 form a formwork, so that on a construction site, in-situ concrete orTop-up concrete 27 can be poured onto parts of the lattice girders 6 projecting from the recess 5 in order to connect the cross-laminated timber panel 14 via the concrete 4, the lattice girder 6 and the in-situ concrete or top-up concrete 27 with the precast concrete elements 9, so that a stable ceiling 13 is formed.

[0062] Cavities in the precast concrete elements 9 are used here for piping 18 to guide lines 29 such as installation lines. Compared to state-of-the-art concrete ceilings, a Fig. 2 The ceiling 13 shown can be constructed on a construction site with very little concreting effort, since only the concrete topping 27 needs to be applied to the parts of the lattice girders 6 protruding from the recess 5, while all other parts can be prefabricated. This makes it possible to construct a building with a very high degree of prefabrication. Furthermore, a self-supporting ceiling 13 is easily achieved, which has a visually appealing wooden underside and reinforced concrete girders.

[0063] Fig. 3 shows a further composite element 1 not according to the invention, which is usually completely manufactured in advance in a precast plant by positioning formwork above and to the side of the recess 5, after which the lattice girder 6 is completely cast in concrete 4. With a composite element 1 designed in this way, concreting on a construction site is no longer necessary, which is why, for example, a ceiling 13 can be manufactured entirely using dry construction. In order to be able to subsequently lay cables 29 in the ceiling 13 easily, recesses 24 are provided in the concrete 4, through which cables 29 can also be guided transversely to a longitudinal extension of the girders made of concrete 4 or reinforced concrete, wherein the girders are usually elongated and protrude from one side wall 7 of a building to the next side wall 7 of the building.

[0064] Such a ceiling 13 is for example in Fig. 4 As can be seen, even with such a ceiling 13, a cavity 21 is achieved between an upper side of a floor 16 of a storey of a building and a lower side of a ceiling 13 of a storey below, in which cavity 21, for example, piping 18 can be positioned. Directly below the floor 16 formed by prefabricated slabs 23, on or in a

[0065] Pipes 20 are arranged on a fiber mat 22 to heat or cool an interior space. As shown, the second elements 3, constructed as supports and made of concrete 4 or reinforced concrete, have recesses 24 here so that pipes 29 can also be laid transversely or perpendicularly to a direction in which the supports run. In this embodiment, the first element 2 is also constructed as a wooden ceiling, consisting of cross-bonded single-layer boards and having a thickness of approximately 100 mm.

[0066] A connection between a base 16 positioned above the second elements 3 and the second elements 3 is made via an elastic adhesive 17, which reduces vibrations. This achieves effective sound insulation.

[0067] Fig. 5 shows a further embodiment of a composite element 1 not according to the invention, wherein a thermal insulation 8 is arranged between the first element 2 and the second element 3. Such a composite element 1 is usually manufactured by, in a first step, forming a composite element 1 according to Fig. 1 is formed, after which the thermal insulation 8 is positioned adjacent to the recess 5 on the first element 2, which here is also designed as a cross-laminated timber panel 14, after which topping concrete 27 is applied, which covers the reinforcement designed as a lattice girder 6 and the thermal insulation 8. When the topping concrete 27 hardens, the thermal insulation 8 is fixed in a form-fitting manner by the hardened topping concrete 27 and thus connected to the cross-laminated timber panel 14 and the second element 3 formed by concrete 4 and lattice girder 6. A wood-concrete composite panel formed in this way can advantageously be used as a thermally insulating ceiling 13 in a building, without the need for on-site concreting.

[0068] Fig. 6 shows a composite element 1 according to Fig. 5 , wherein a displacement body 30 is positioned adjacent to the recess 5 on only one side and spaced apart from the recess 5 on an opposite side, so that installation pipes can be arranged between the recess 5 and the insulating material, which are also enclosed in the topping concrete 27, which is applied in the second step after positioning the displacement body 30. The displacement body 30 can of course be designed in a variety of ways, for example to achieve certain physical properties such as sound insulation, thermal insulation 8 or particularly high stability.

[0069] Fig. 7 shows a further composite element 1 not according to the invention, in which an area above the first element 2, also designed here as a cross-laminated timber panel 14, is completely filled with concrete topping 27. Furthermore, transverse reinforcement 28 is also provided in order to achieve a particularly high strength of the composite element 1 or a ceiling 13 of a building.

[0070] To achieve a very high strength of a ceiling 13, the reinforcement can also be designed as a steel beam 15 instead of a lattice girder 6. Such a ceiling 13 of a building is in Fig. 8 Concrete 4 is typically constructed as microfiber concrete, ensuring high strength and low shrinkage upon curing.

[0071] Fig. 9 shows a further embodiment of a ceiling 13 of a building with a composite element 1 not according to the invention according to Fig. 3 in sectional view. In the Fig. 9 In the ceiling 13 shown, a floor 16 of an upper storey is formed by prefabricated slabs 23, typically precast concrete slabs, which are connected to the second element 3, designed as a reinforced concrete beam, via an elastic adhesive 17 in order to reduce vibrations. Furthermore, pipes 20 are arranged beneath the prefabricated slabs 23 in a bulk material 31, generally a bulk material available under the name Liapor Ground, so that the ceiling 13 can be used for heating or cooling purposes. The bulk material 31 is arranged between the prefabricated slabs 23 and the first element 2, designed as a cross-laminated timber panel 14, in order to achieve favorable structural properties.

[0072] Fig. 10 shows a section of a further ceiling 13 with a composite element 1 not according to the invention. Fig. 10 The ceiling 13 shown contains a second element 3 with reinforcement, which has four lower chords 12 and three upper chords 11, which are connected by steel elements (not shown) of the lattice girder 6. This achieves a very high strength, so that even with a low ceiling thickness, a large span can be achieved. Fig. 10 The ceiling 13 shown includes floor elements constructed as prefabricated slabs 23, on which a floor covering 32 is positioned. Here, too, a connection is made using an elastic adhesive 17 to reduce vibrations.

[0073] Another example is in Fig. 11 Deviating from the Fig. 10 In the ceiling 13 shown, the floor 16 of this ceiling 13 is formed by cross-glued single-layer panels or a cross-laminated timber panel 14 and a floor covering 32.

[0074] Fig. 12 shows a section of a ceiling 13 with a composite element 1 not according to the invention, in which the composite element 1 is mounted on a side wall 7 formed by a cross-laminated timber panel 14, in a sectional view through a second element 3 designed as a support. As can be seen, the second element 3 partially projects into the side wall 7, so that forces from the ceiling 13 or the floor 16 can be transmitted to and dissipated from the side wall 7 via the second element 3 designed as a support. The first element, also designed here as a wooden ceiling, is supported by the second element 3 or hangs from the second element 3.

[0075] Fig. 13 shows another section through the Fig. 12 illustrated ceiling 13 in an area between two second elements 3 or between two second elements 3. As can be seen, in this area the first element 2 designed as a wooden ceiling projects into the side wall 7.

[0076] Fig. 14 shows a further ceiling 13 of a building with a composite element 1 not according to the invention. As can be seen, pipes 20 for heating or cooling are arranged above the second elements 3 in concrete slabs 33 in order to ensure efficient heat transfer.

[0077] Fig. 15 shows an area in which a ceiling 13 of a building rests on side walls 7, the side walls 7 being formed by masonry 25 or bricks. As can be seen, the first element 2, designed as a wooden ceiling, projects into the side wall 7 here too. A connection between the ceiling 13 and the side wall 7 is further established via the second elements 3, designed as reinforced concrete beams. An elastic material is arranged between the ceiling 13 and the masonry 25 in order to achieve shell decoupling. In order to fix the ceiling 13 in the masonry 25, a space between the masonry 25 and the composite element 1 is filled with a cast concrete 26.

[0078] Fig. 16 shows a further composite element 1 not according to the invention, wherein the recess 5 has a variable cross-section along a longitudinal direction 39, so that shear cams are formed in the recess. As can be seen, the projecting and subsequently tapered side edges 38 of the recess 5 on a surface 10 of the first element 2 form a shear cam 37 for transmitting forces in the longitudinal direction 39 between the first element 2 and the hardened concrete 4 in the recess 5.

[0079] One in Fig. 16 The recess 5 shown with a dovetail-shaped cross-section and additional push cams 37 can be produced, for example, by milling a dovetail-shaped recess along the longitudinal direction 39 into the first element 2, which is usually made of wood, preferably laminated veneer lumber, in particular construction beech, after which the push cams 37 are introduced, for example by milling. The push cams 37 can have a cross-section that remains constant in the vertical direction or in a direction perpendicular to the surface 10 of the first element 2.

[0080] In Fig. 17 is a Fig. 16 illustrated composite element 1 or a first element 2 of a corresponding composite element 1 is shown in a plan view. As can be seen, the six approximately arrow-shaped shear cams 37 form positive connections between the first element 2 and the concrete 4 at several positions, so that shear forces can be easily transmitted and high flexural rigidity and flexural strength are achieved. Six arrow-shaped shear cams 37 are provided, with three shear cams 37 being oriented along the longitudinal direction and three shear cams counter to the longitudinal direction, so that several shear cams 37 are arranged in opposite directions in the recess 5 in order to enable uniformly good transmission of forces along the longitudinal direction 39.

[0081] As shown, the orientation of the arrow-shaped thrust cams 37 is advantageously selected such that, in a plan view, the thrust cams 37 taper toward a center of the composite element 1, or the arrow-shaped thrust cams 37 point toward a center of the composite element 1. This enables optimal stress distribution in the wood and in the concrete 4 when the first element 2 is designed as a wood element and the cured material as concrete 4.

[0082] Fig. 18 shows a further composite element 1 not according to the invention or a first element 2 of a corresponding composite element 1 in plan view, wherein the push cams 37 are approximately rectangular. It is understood that other shapes of the push cams 37 are also possible. Furthermore, the corners of the push cams 37 can, of course, also be rounded to avoid stress peaks.

[0083] A cross-section of the Fig. 16 bis 18 The cross-section of the composite elements 1 shown thus changes along the longitudinal direction 39, whereby the cross-section can also be designed as a dovetail cross-section. Typically, a depth of the cross-section or a distance of a lower edge of the cross-section from the surface 10 of the first element 2 remains approximately constant over a length of the recess 5 or along the longitudinal direction 39. Fig. 19 und 20 show further inventive

[0084] Composite elements 1 in a sectional view. Here, a positive connection between the first element 2 and the concrete 4 is not achieved via a cross-section of the recess 5 with tapered side surfaces 19, but via a connecting element designed as a mandrel, which is also referred to as a shear mandrel 34. The shear mandrel 34, which is usually made of a high-strength material such as metal, in particular steel, or a fiber material such as glass fiber or a fiber composite material, is positively connected to the first element 2 by positioning the shear mandrel 34, which can have a diameter of 16 mm, for example, in bores 40 in the first element 2. The concrete 4 encloses the shear mandrel 34, so that a load-bearing connection is achieved between the concrete 4 and the first element 2 both in the longitudinal direction 39 and perpendicular to a surface 10 of the first element 2 or in the vertical direction.Here too, reinforcement is provided in the concrete 4, which in the example shown has lower chords 12 and an upper chord 11 and is connected to a transverse reinforcement 28.

[0085] The Fig. 20 Composite element 1 shown essentially corresponds to the one shown in Fig. 19 illustrated composite element 1, however here the first element 2 itself is divided into two parts and consists of a first partial element 35 and a second partial element 36, which are connected via the shear pin 34. During production of this composite element 1, the shear pin 34 is positioned in a bore 40 in the first partial element 35, after which the second partial element 36 is moved to the first partial element 35, wherein the shear pin 34 is inserted into a bore 40 in the second partial element 36. In this process, the first partial element 35 is connected to the second partial element 36. As a result, the shear pin 34 is positively connected in all directions to the first partial element 35 and the second partial element 36. Subsequently, the reinforcement is placed in the recess 5, the recess 5 is filled with concrete 4 and the partial elements 35, 36 are connected. This results in a connection between the first element 2 and the hardened material that is load-bearing in all directions.

[0086] In the Fig. 19 und 20 In the illustrated embodiments, the cross-section of the recess 5 is rectangular. A dovetail-shaped cross-section is not required here for transmitting forces in the vertical direction, since vertical forces can also be transmitted via the connecting element designed as a shear pin 34. Of course, even when using a shear pin 34, the cross-section of the recess 5 can, in principle, be of any desired shape, in particular, even dovetail-shaped.

[0087] Fig. 21 shows a detail of an embodiment of a composite element 1 according to the invention before the completion of the second element 3, so that the recess 5 in the first element 2 and the reinforcement are clearly visible. As can be seen, the recess 5 has an arrow-shaped area in which the reinforcement is positioned, which reinforcement here also has an upper chord, a lower chord and a lattice girder. Connected to the reinforcement is a metal part formed by a steel stirrup 41, which, as shown, extends into the arrow-shaped area of ​​the recess 5, which area here forms a local widening of the recess 5, in order to achieve a particularly good connection between the first element 2, which here is also essentially formed by a wooden panel, and the second element 3, which is still to be formed, for the transmission of shear forces. Of course, this composite element 1, like the one in Fig. 17shown along the longitudinal direction 39 have a plurality of arrow-shaped areas or arrow-shaped shear cams 37, in each of which a corresponding reinforcement is arranged in order to connect the concrete 4 to the first element 2 in a shear-resistant manner.

[0088] As can be seen, the steel bracket 41 extends in regions along the oblique side edges 38 of the arrow-shaped region of the recess 5 and the oblique regions of the steel bracket 41 are connected by a part of the steel bracket 41 which is aligned approximately normal to a longitudinal direction 39 of the recess 5.

[0089] In addition to a steel stirrup 41, the lower chords 12 of the reinforcement could of course also extend into the widening or into the arrow-shaped area.

[0090] By means of such a particularly shear-resistant connection, the formation of stable ceiling elements is ensured, even for large spans, with a low weight of the composite element 1.

[0091] All illustrated embodiments of composite elements 1 can be manufactured partially or entirely in a precast concrete plant or entirely on-site and can be used in combination with piping 18, insulation materials, displacement bodies 30, and precast panels 23 to form structures of various types. The use of composite elements according to the invention therefore provides a high degree of flexibility.

[0092] Using a composite element 1 according to the invention, a wooden ceiling in a building can be formed in a particularly cost-effective and process-reliable manner. This allows visually appealing ceilings 13 to be formed at low cost and without the need for concreting on site, even in buildings that have reinforced concrete elements as load-bearing components.

Claims

1. Method for producing a composite element (1), characterized in that a first element (2) with a recess (5) is provided, which recess (5) extends substantially along a longitudinal direction (39) and has a cross section that is variable over the longitudinal direction (39) with arrow-like shear cams (37), which are designed as recesses having wider and narrower regions along the longitudinal direction (39), after which a reinforcement is positioned in the recess (5), partly protruding from the recess (5), after which the recess (5) is filled with curable material, in particular concrete (4), after which the curable material cures in the recess (5), forming a second element (3), so that the reinforcement is connected to the first element (2) in form-fitting manner by the cured material, wherein a metal part formed by a steel clip (41) is positioned in the recess (5), at least an area of which metal part is aligned at an angle of 45 degrees to 135 degrees, in particular 80 degrees to 100 degrees, relative to a longitudinal direction (39) of the recess (5) and is connected to bottom chords (12) of the reinforcement, and extends into the wider regions of the shear cams (37), characterized in that the metal part formed by a steel clip partially extends along inclined lateral edges (38) of the arrow-like shear cams (37), wherein inclined regions of the steel clip (41) are connected by a part of steel clip (41) that is aligned approximately normally to a longitudinal direction (39) of the recess, so that a locally greater distance between the bottom chords (12) is stabilised mechanically by means of the steel clip (41).

2. Method according to Claim 1, characterized in that a displacement body (30), preferably a filling material, a hollow body and / or formwork, is positioned adjacent to the recess (5) on the first element (2), after which curable material, in particular fibre concrete, preferably micro-fibre concrete, is applied to the part of the reinforcement that protrudes from the recess (5), so that the reinforcement is substantially encased in the curable material, wherein the curable material is preferably applied in such a way that after curing of the curable material the displacement body (30) is fixed in place relative to the first element (2) by said material.

3. Method according to Claim 1 or 2, characterized in that the first element (2) is formed by providing at least two sub-elements (35, 36) which are connected, wherein the sub-elements (35, 36) are connected in particular via a connecting element, preferably a mandrel, which is connected to a first sub-element (35) at a first end and connected to a second sub-element (36) at a second end and extends through the recess (5).

4. Method for constructing a building, characterized in that a composite element (1) produced according to one of claims 1 to 3 is used.

5. Method according to Claim 4, characterized in that in a first step in a precast plant the recess (5) is filled with curable material, which cures in the recess (5), after which the composite element (1) is transported to a construction site and arranged adjacent to further construction components, after which in a second step additional curable material is applied to a part of the reinforcement that protrudes from the recess (5), so that the composite element (1) is connected to the further construction components via the second curable material as this curable material cures.

6. Method according to Claim 4, characterized in that all curable material is applied in advance, in a precast plant, for example, after which the composite element (1) is transported to a construction site where the composite element (1) is connected to other construction components of the building substantially without use of a water-containing building material.

7. Composite element (1), having a first element (2) with a recess (5) with a cross section that is variable along a longitudinal direction (39), wherein the recess (5) has arrow-like shear cams (37) with wider and narrower regions along a longitudinal direction (39), and at least one second element (3) connected to the first element (2), which second element includes a cured material and a reinforcement, wherein the at least one second element (3) protrudes at least partially from a recess (5) in the first element (2) and is connected in form-fitting manner to the first element (2) in the recess (5), wherein the composite element (1) is produced in particular in a method according to any one of Claims 1 to 6, wherein a metal part formed by a steel clip (41) is positioned in the recess (5), which metal part extends into the wider regions and at least part of which is aligned at an angle of 45 degrees to 135 degrees, in particular 80 degrees to 100 degrees, relative to a longitudinal direction (39) of the recess (5) and is connected to bottom chords (12) of the reinforcement, characterized in that the metal part formed by a steel clip is partially aligned approximately parallel to an inclined side edge (38) of the arrow-like shear cams (37) of the recess (5), so that a locally greater distance between the bottom chords (12) is stabilised mechanically by means of the steel clip (41).

8. Composite element (1) according to Claim 7, characterized in that the reinforcement is constructed as a lattice girder (6), wherein two bottom chords (12) and one top chord (11) are provided, and the bottom chords (12) are positioned in the recess (5).

9. Composite element (1) according to Claim 7 or 8, characterized in that in a plan view at least regions of the recess (5) are designed with converging side edges (38).

10. Composite element (1) according to any one of Claims 7 to 9, characterized in that the recess (5) is elongate and closed at the sides.

11. Composite element (1) according to any one of claims 7 to 10, characterized in that at least two shear cams are orientated inversely.

12. Composite element (1) according to any one of Claims 7 to 11, characterized in that the reinforcement is embodied as a textile reinforcement, in particular with glass and / or carbon fibres.

13. Building with a composite element (1), characterized in that the composite element (1) is embodied according to any one of Claims 7 to 12, wherein the first element (2) preferably forms a ceiling (13) of an interior space, which is substantially supported by at least one second element (3).

14. Building according to Claim 13, characterized in that the at least one second element (3) is designed approximately in the form of an I-beam.

15. Building according to Claim 13 or 14, characterized in that pipes (20) are positioned inside the second element (3) to enable the building to be heated and / or cooled by the composite element (1).