Semi-finished component, timber-concrete composite structural element, use, and method

Abstract

The invention relates to a semi-finished component (104, 204, 404) for manufacturing a timber-concrete composite structural element (100, 200, 400), the semi-finished component comprising a stacked arrangement (106) which has a plurality of bottom chord elements (108, 109) made of wood and a plurality of rib elements (110, 310), wherein the plurality of bottom chord elements (108, 109) and the plurality of rib elements (110, 310) are arranged side by side in a stacking direction (112) and are adhesively bonded to one another, such that the bottom chord elements (108, 109) and the rib elements (110, 310) together form a bottom face (114) and an opposite top face (116) of the stacked arrangement (106), wherein the rib elements (110, 310) comprise, at the top face (116), projecting portions (122) which project beyond the bottom chord elements (108, 109) in order to be at least partially embedded in concrete, wherein the plurality of bottom chord elements (108, 109) and the plurality of rib elements (110, 310) are arranged alternately side by side in the stacking direction (112), and the rib elements (110, 310) are made of a wood-based material. The invention also relates to the use of the semi-finished component (104, 204, 404), as well as to a timber-concrete composite structural element (100, 200, 400) and to a method for manufacturing same.

Description

[0001] September 4, 2025

[0002] Semi-finished product, timber-concrete composite element, use and process

[0003] The present invention relates to a semi-finished component for the production of a timber-concrete composite building element, in particular a timber-concrete composite slab or a timber-concrete composite precast element. The present invention further relates to a timber-concrete composite building element, in particular a timber-concrete composite slab or a timber-concrete composite precast element. The present invention further relates to a use of the semi-finished component for the production of a timber-concrete composite building element. The present invention further relates to a method for the production of a timber-concrete composite building element.

[0004] Composite timber-concrete slabs are a known technology. However, their construction is more complex and therefore more expensive than that of concrete slabs. Key cost drivers include the measures required to bond the timber to the concrete. Furthermore, existing systems do not optimally utilize the mechanical properties of their components and their interaction.

[0005] EP 1 582 644 discloses a timber-concrete composite slab in which the bond between timber and concrete is achieved by notches in the timber in combination with screws connecting the timber and concrete. The use of screws involves considerable labor and material costs. Furthermore, the notches reduce the cross-sectional area, necessitating greater overall thicknesses to meet structural requirements. EP 0 528450 discloses a timber-concrete composite slab in which the bond between timber and concrete is achieved using timber-concrete composite screws, which involves even greater labor costs. Systems with bonded expanded metal or other mechanical fasteners are also known, which likewise result in complex manufacturing and / or assembly processes.EP 0952 271 discloses a wood-concrete composite element comprising a wood component made of numerous boards joined together in a cross-laminated timber (CLT) construction and a concrete component. Composite webs made of solid wood are inserted between several boards of the wood component to embed it in the concrete component. However, solid wood has only moderate transverse tensile strength and also natural weaknesses, such as knots, which can lead to cracking of the composite web and thus failure of the bond between the concrete and wood, and consequently of the entire component. According to EP 0 952 271, composite sheets or composite webs made of plastic, steel mesh, or woven fabric can also be used instead of solid wood composite webs. These can be attached to the CLT, for example, by gluing or screwing.However, this leads to more complex manufacturing due to the diverse and costly materials, especially when it comes to bonding them together.

[0006] From EP 1992 755, a timber-concrete composite component is further disclosed, comprising a compression flange made of concrete and one or more tension flanges made of wood-based material or timber. The one or more tension flanges have recesses facing the compression flange into which webs are inserted, connecting the tension flanges to the concrete compression flange. These recesses reduce the cross-sectional area and thus weaken the tension flanges.

[0007] Against this background, the present invention aims to provide a wood-concrete composite building element and a semi-finished product for its manufacture, which at least partially reduces or avoids the disadvantages described above.

[0008] This problem is solved according to the invention by a semi-finished product for the production of a timber-concrete composite building element, in particular a timber-concrete composite slab or a timber-concrete composite precast element, with a stacking arrangement,

[0009] SE / SE 240712WO

[0010] 4 September 2025 comprising several bottom chord elements made of wood and several web elements, wherein the several bottom chord elements and the several web elements are arranged side by side in a stacking direction and glued together, so that the bottom chord elements and web elements together form a bottom and an opposite top of the stacking arrangement, wherein the web elements have areas projecting beyond the bottom chord elements on the top side for their at least partial embedding in concrete, wherein the several bottom chord elements and the several web elements are arranged alternately side by side in the stacking direction and wherein the web elements are made of wood-based material.

[0011] Solid wood is a highly inhomogeneous material, exhibiting significant inhomogeneities in cross-section, particularly due to knots or irregular grain patterns. Compared to web elements made of solid wood, web elements made of engineered wood have more consistent properties, thus reducing the risk of failure of the wood-concrete composite element produced with the precast element due to inherent weaknesses in solid wood, such as knots.

[0012] Engineered wood products also have the advantage of better resource utilization compared to solid wood. For example, a larger proportion of the original wood can be used in the production of engineered wood products than when cutting solid wood.

[0013] Furthermore, engineered wood products can be manufactured from lower-grade and recycled wood that exhibit the same or even higher load-bearing capacity as higher-grade solid wood. In particular, the web elements made of engineered wood can exhibit significantly higher tensile strength in the panel direction (i.e., in the longitudinal direction) and in the vertical direction (i.e., from the bottom to the top of the stacked semi-finished part) than the transverse tensile strength of solid wood.

[0014] This way, resources can be saved and the semi-finished product can be produced more cheaply.

[0015] SE / SE 240712WO

[0016] September 4, 2025 Furthermore, a surprising advantage arises from the alternating arrangement and bonding of web elements made of wood-based material and bottom chord elements made of wood:

[0017] When a solid wood bottom chord element is subjected to tensile stress, homogeneous, fiber-parallel stresses occur in homogeneous areas of the wood with parallel grain direction across the entire cross-section. However, in areas of inhomogeneity, such as knots or inhomogeneous grain patterns, significant deviations and deflections of the stress distribution occur, since knots, for example, possess only a fraction of the strength and stiffness of undisturbed wood. Consequently, the stresses increase due to redirection into the remaining cross-section of the bottom chord element, and this redirection, combined with oblique grain directions, results in stresses perpendicular to the otherwise normal grain direction of the wood. This can lead to premature failure of the bottom chord element, as the wood initially cracks in the knot area when the load increases, and the loads from this area are redistributed into the remaining cross-section.This redistribution leads to high local transverse tensile stresses as well as additional bending stresses from the deformation in the cracked wood cross-section, causing the wood to crack perpendicular to the grain and the crack to spread further along the grain, resulting in very rapid overall failure of the wood cross-section.

[0018] It was found that such premature failure of the bottom chord element can be prevented by alternating the arrangement of glued web elements made of wood-based material and bottom chord elements made of wood.

[0019] Due to the more homogeneous properties of the wood-based material, the web elements exhibit quite high strength even perpendicular to the grain of the wood in the bottom chord elements. The double-sided bonding of the bottom chord elements to adjacent web elements prevents localized cracking of the bottom chord elements perpendicular to the grain in areas of inhomogeneity such as knots, or warping.

[0020] SE / SE 240712WO

[0021] September 4, 2025. In the event of failure, bottom chord elements are prevented from failing due to such inhomogeneity. In particular, the load in the bottom chord element can be better distributed across the remaining cross-section via the glued web elements, and the low transverse tensile strength of the solid wood is compensated for by the high strength of the engineered wood used in the web elements. This leads to a significant increase in load-bearing capacity, allowing the bottom chord elements and, if applicable, web elements to be dimensioned smaller and therefore more cost-effectively. With web elements made of solid wood, this effect would not occur, or would only occur to a greatly reduced extent, due to the low transverse tensile strength of solid wood.

[0022] The precast element is intended for the production of a timber-concrete composite structure. This timber-concrete composite structure could, in particular, be a timber-concrete composite slab. For this purpose, one or more precast elements can be positioned and joined with cast-in-place concrete to form a timber-concrete composite structure, especially a timber-concrete composite slab. It is also conceivable that the precast element is used to produce a precast timber-concrete composite element, which is then positioned and, for example, grouted with concrete around its edges.

[0023] The semi-finished product features a stacking arrangement comprising several bottom chord elements made of wood and several web elements. The bottom chord elements and web elements extend, in particular, in a longitudinal direction that runs transversely to the stacking direction. The bottom chord elements and web elements extend, in particular, parallel to each other in their longitudinal direction. The bottom chord elements can, in particular, be in the form of boards or squared timber. Preferably, the bottom chord elements have a rectangular cross-section transverse to their longitudinal direction.

[0024] The stacking arrangement can, for example, have a width in the stacking direction in the range of 0.5–2.5 m, preferably 0.75–2 m, and in particular 1–1.5 m.

[0025] SE / SE 240712WO

[0026] 4 September 2025 The stacking arrangement can, for example, have a length in the longitudinal direction (span) in the range of 1 - 15 m, preferably 2.5 - 10 m, in particular 5 - 8.5 m.

[0027] The bottom chord elements are made of wood, in particular solid wood. The bottom chord elements can, in particular in the longitudinal direction, have several connected, in particular finger-jointed, solid wood sections.

[0028] The bottom chord elements, in combination with the webs arranged between them, serve as tension chords to absorb tensile forces in the finished timber-concrete composite element. The sections of the webs that project beyond the bottom chord act as spacers between the bottom chord and the concrete top chord in the finished timber-concrete composite element, connecting the precast element to a layer of concrete. For this purpose, the webs have sections on their upper surface that project beyond the bottom chord elements, allowing for at least partial embedding in the concrete.

[0029] The multiple bottom chord elements and the multiple web elements are arranged alternately side by side in a stacking direction and connected to each other, so that the bottom chord elements and web elements together form a bottom and an opposite top of the stacked arrangement. The bottom and the top are therefore formed by the respective surfaces of the alternately arranged bottom chord elements and web elements.

[0030] The alternating arrangement of the bottom chord elements and web elements means that each bottom chord element is bonded to web elements on both sides, which – as described above – allows for a more even distribution of tensile forces and a limitation of crack lengths.

[0031] The top side is the side of the stacked arrangement that faces the concrete layer in the finished wood-concrete composite element. On this top side...

[0032] SE / SE 240712WO

[0033] On September 4, 2025, the web elements protrude beyond the bottom chord elements and can thus serve as spacers between the bottom chord elements and the concrete layer in the finished timber-concrete composite element, and, through the at least partial embedding of the protruding areas in the concrete layer, as a connection between the stacking arrangement and the concrete layer.

[0034] The underside of the stacked arrangement is preferably essentially flat. In this way, for example, a flat underside can be achieved for a timber-concrete composite slab manufactured from the precast element.

[0035] The alternating arrangement of the bottom chord elements and web elements fully integrates the web elements into the stacking arrangement without weakening the cross-section of the bottom chord elements. This results in a statically very efficient cross-section for the bottom chord elements without any weakening.

[0036] The alternating bottom chord elements and web elements are bonded together. The bond between the bottom chord elements and the adjacent web elements is preferably substantially full-surface. This prevents the bottom chord elements from splitting perpendicular to the grain. Without such bonding, solid wood can split on one side under high loads, particularly in areas of weakness, such as a knot. Due to the low tensile strength perpendicular to the grain and the typical diagonal grain of solid wood, such a crack propagates through the wood, potentially leading to total failure. Bonding the bottom chord elements to the web elements prevents this mechanism and increases the load-bearing capacity of the bottom chord elements. In particular, bonding the bottom chord elements to the web elements inhibits crack propagation and thus limits crack lengths.

[0037] SE / SE 240712WO

[0038] September 4, 2025 Furthermore, the adhesive bonding can optimize the swelling properties of the stack arrangement in the presence of moisture, since the different swelling properties of the bottom chord elements and web element partially block each other, and the adhesive bonding also acts as a moisture barrier.

[0039] In addition, the bottom chord elements and adjacent web elements can also be connected to each other in a form-fit and / or force-fit manner, for example by being screwed or nailed together, for example by means of steel nails or hardwood nails.

[0040] The web elements are made of wood-based material. The wood-based material is, in particular, a panel material. Preferably, the wood-based material of the web elements contains wood chips.

[0041] The wood-based material preferably contains wood particles, for example wood chips or wood fibers, and a binder, for example a resin, in particular a synthetic resin such as melamine resin. In particular, the web elements can be made of particleboard, especially particleboard P5 or P7 according to EN 712, of OSB (Oriented Strand Board), especially OSB / 3 or OSB / 4 according to EN 300, or of flakeboard. Preferably, the wood-based material consists of at least 50 wt.%, and more preferably at least 80 wt.%, of wood particles. Furthermore, the wood-based material preferably contains a binder with a content in the range of 2–12 wt.%.

[0042] The wood-based material can also be a panel material composed of veneer layers, in particular plywood or laminated veneer lumber (LVL).

[0043] The wood fibers of the wood-based material, particularly in OSB or plywood, are preferably oriented in at least two main directions of the web elements, especially in the longitudinal direction and the vertical direction, i.e. in the direction

[0044] SE / SE 240712WO

[0045] September 4, 2025, from the underside to the top of the stack arrangement. Alternatively, the wood fibers of the engineered wood product, particularly in particleboard or fiberboard, can be oriented randomly. Due to this fiber orientation, such materials exhibit higher shear strength, shear stiffness, and transverse tensile strength compared to natural wood. In this way, a more shear-resistant and durable connection between the bottom chord elements and the concrete layer can be achieved via the web elements.

[0046] The aforementioned problem is further solved according to the invention by a wood-concrete composite element comprising the previously described precast element or an embodiment thereof and a concrete layer, wherein the projecting areas of the web elements are embedded, in particular cast, at least partially into the concrete layer. The precast element, in particular its bottom flange elements, and the concrete layer are connected to each other, in particular in a shear-resistant manner, by the projecting areas of the web elements of the precast element being embedded, at least partially, in the concrete layer.

[0047] The timber-concrete composite element can be, in particular, a timber-concrete composite slab. The concrete layer can be produced using cast-in-place concrete. Alternatively, the timber-concrete composite element can be a prefabricated timber-concrete composite element, especially a slab element, which is provided with a concrete layer during manufacturing before being transported to the installation site.

[0048] The timber-concrete composite element has a concrete layer. The concrete layer can consist of normal concrete, in particular with compressive strengths C20 / 25 to C30 / 37. If required, concrete with a higher strength class can also be selected. Furthermore, the concrete layer can consist of steel fiber reinforced concrete. Preferably, a low-shrinkage concrete mix is ​​used for producing the concrete layer. The concrete layer preferably has a thickness in the range of 20–150 mm, preferably 40–100 mm, and particularly 50–80 mm. In this way, a

[0049] SE / SE 240712WO

[0050] On September 4, 2025, a good compromise between weight and load-bearing capacity was achieved in combination with the semi-precast element. The concrete layer or the concrete mix used for its production preferably has a maximum aggregate size of < 30 mm, more preferably < 25 mm, and particularly < 16 mm.

[0051] Reinforcement can be embedded in the concrete layer. This helps to limit the crack widths in the concrete layer. The reinforcement can, in particular, comprise a reinforcing steel mesh or individual reinforcing bars. Preferably, the reinforcement extends beyond the concrete layer in the longitudinal direction. This allows the timber-concrete composite element to be embedded longitudinally in cast-in-place concrete, for example, in a ring beam.

[0052] The aforementioned problem is further solved according to the invention by using the previously described semi-finished product or an embodiment thereof for the production of a timber-concrete composite element, in particular the previously described timber-concrete composite element or an embodiment thereof. In particular, during the production of the timber-concrete composite element, the protruding areas of the web elements are partially embedded in concrete.

[0053] The aforementioned problem is further solved according to the invention by a method for producing the previously described wood-concrete composite element or an embodiment thereof. In the method, the previously described semi-finished element or an embodiment thereof is provided. Furthermore, in the method, at least an upper part of the projecting areas of the web elements of the semi-finished element is embedded in uncured concrete, so that when the concrete cures, a concrete layer is formed in which at least the upper part of the projecting areas of the web elements is embedded.

[0054] The process optionally allows for the insertion of a filling material and / or one or more installation lines and / or empty conduits between the protruding

[0055] SE / SE 240712WO

[0056] The installation lines and / or conduits can be arranged in the areas from September 4, 2025. They can run, for example, in the stacking direction and / or longitudinally. The arrangement of the fill material or the one or more installation lines or conduits for it can take place before or after embedding at least the upper part of the protruding areas of the web elements of the precast element in uncured concrete.

[0057] In one embodiment of the process, the semi-prefabricated element is positioned with the protruding sections of the web elements facing upwards, and the uncured concrete is applied to the timber-concrete composite element. In this embodiment, any filler material is preferably placed between the protruding sections before the concrete is applied. In this way, the filler material can act as a spacer between the bottom chord elements and the concrete.

[0058] The prefabricated element can be positioned on-site, for example, on one or more supports, particularly the walls of a building. Alternatively, the concrete can be poured in place. In this way, a timber-concrete composite slab can be constructed on-site.

[0059] However, it is also conceivable that the wood-concrete composite element is manufactured as a prefabricated wood-concrete composite element, which is then transported to its place of use.

[0060] In an alternative embodiment of the process, the precast element is oriented with the protruding web elements facing downwards and immersed with at least the upper part of the protruding web elements into uncured concrete. In this way, the distance between the bottom chord elements and the concrete layer can be adjusted by the immersion depth of the web elements in the uncured concrete, independent of any filler material between the protruding areas. This embodiment thus allows the production of timber-concrete composite elements without filler material between the

[0061] SE / SE 240712WO

[0062] September 4, 2025, protruding areas or the subsequent insertion of filler material between the protruding areas. This design is particularly advantageous for the production of precast wood-concrete composite elements.

[0063] The following describes various embodiments of the semi-finished product, the timber-concrete composite element, the method, and its use, with each embodiment applying independently to the semi-finished product, the timber-concrete composite element, the method, and its use. Furthermore, the individual embodiments can be combined with one another as desired.

[0064] In one embodiment, the bottom chord elements are made of solid structural timber. This material is particularly advantageous for the tension chord function of the bottom chord elements in the timber-concrete composite component.

[0065] The bottom chord elements can be designed as a single piece of solid wood extending along the longitudinal direction, covering essentially the entire length of the stacking arrangement. Alternatively, the bottom chord elements may consist of several solid wood pieces joined along the longitudinal direction by means of tension-transmitting longitudinal joints, such as finger joints or scarf joints.

[0066] The solid wood of the bottom chord elements preferably has a strength class in the range C14 to C30, more preferably C16 to C24, according to EN 338:2016 or an equivalent grading class.

[0067] In one embodiment, the bottom chord elements have a width in the stacking direction of 40–200 mm, preferably 60–150 mm, and particularly 75–120 mm. The use of relatively narrow bottom chord elements between each pair of web elements ensures that stresses occurring in the bottom chord elements are distributed more evenly across the web elements to which they are bonded. In particular, this prevents stresses from being distributed at a natural weak point.

[0068] SE / SE 240712WO

[0069] From September 4, 2025, transverse forces occurring in a bottom chord element, for example due to a branch, are transferred via the web elements located near the narrow bottom chord elements. Furthermore, the lengths of any cracks that may occur in the bottom chord elements are limited by the nearby web elements.

[0070] In particular, the closely spaced web elements in the stacking direction create a strong bond between the bottom chord elements and the concrete layer. The preferably full-surface bonding of the web elements and bottom chord elements achieves a close spacing of the adhesive layers in the stacking direction, further strengthening the bond and, in particular, preventing the bottom chord elements from cracking perpendicular to the grain. This increases the load-bearing capacity of the timber-concrete composite element produced with the precast component.

[0071] In one embodiment, the bottom chord elements have a height in the range of 40–160 mm, preferably 50–100 mm, and particularly 50–70 mm. The height of the bottom chord elements extends, in particular, transversely to the stacking direction, from the underside to the top of the stacked arrangement. It has been found that with the proposed prefabricated element, good load-bearing capacities of the resulting timber-concrete composite element can be achieved with relatively small cross-sections of the bottom chord elements. In this way, the prefabricated elements can be manufactured with less material and thus more cost-effectively.

[0072] In one embodiment, the web elements have a width in the stacking direction of 10–25 mm, preferably 12–20 mm, and particularly 14–18 mm. It has been found that these web element widths are sufficient for securely connecting the bottom chord elements to the concrete layer when using web elements made of wood-based material. Furthermore, these relatively small widths ensure that the bottom chord elements constitute a larger relative proportion of the stacking arrangement in the stacking direction, thereby improving the load-bearing capacity of the timber-concrete composite element produced from the precast element.

[0073] SE / SE 240712WO

[0074] On September 4, 2025, the wood of the bottom chord elements exhibits a significantly higher modulus of elasticity, for example, three times higher, than the engineered wood used in the web elements, such as OSB. The larger proportion of bottom chord elements in the overall bottom chord thus results in greater longitudinal stiffness. The relatively narrow widths of the web elements described above are particularly advantageous in combination with the previously described narrow widths of the bottom chord elements. This combination of width ranges simultaneously achieves good stress distribution and crack length limitation, as well as high longitudinal stiffness.

[0075] The dimensions of the bottom chord elements, in particular their height, and / or the dimensions of other load-bearing parts can be adapted to the desired load-bearing capacity and span, i.e., length of the semi-finished part in the longitudinal direction.

[0076] In one embodiment, the areas of the web elements projecting beyond the bottom chord elements on the upper side have a height in the range of 20–600 mm, preferably 50–600 mm, more preferably 200–500 mm, and particularly 250–400 mm. In other words, the web elements preferably project 20–600 mm, more preferably 50–600 mm, and more preferably 200–500 mm, and particularly 200–400 mm, beyond the bottom chord elements on the upper side. In this way, sufficiently deep embedding in the concrete can be achieved during the manufacture of the timber-concrete composite component. Furthermore, the concrete layer can be spaced apart from the bottom chord elements, allowing the concrete layer and the bottom chord elements to be positioned outside the neutral axis, resulting in improved load-bearing properties of the timber-concrete composite component or enabling a reduction in material thickness for the same load-bearing capacity.

[0077] In one embodiment, the protruding areas of the web elements are provided with a profile, in particular in an upper part of the protruding

[0078] SE / SE 240712WO

[0079] September 4, 2025. Areas. In particular, the web elements can have a profiled web edge. In this way, a shear-resistant connection in the longitudinal direction can be achieved between the bottom chord elements and the concrete layer of the timber-concrete composite element to be produced with the precast element. In particular, a positive fit between the web elements and the concrete layer can be achieved in this way, so that the stacked arrangement and the concrete layer are load-bearingly connected. In addition, such a profile can be easily incorporated into the web elements.

[0080] The profiling can be such, for example, that the web elements have recesses at their edges, particularly in the form of a cam profile. The concrete poured into the recesses creates a positive fit, especially in the longitudinal direction. The recesses preferably have a depth (or the cams between them a height) in the range of 5–80 mm, more preferably 10–40 mm, and particularly 15–25 mm. This ensures that the resulting positive connection between the concrete layer and the web elements can effectively absorb tensile forces in the longitudinal direction.

[0081] The recesses can be rectangular. A rectangular shape is easy to produce and provides good absorption of tensile forces in the longitudinal direction. Tensile forces perpendicular to the concrete surface are absorbed to a limited extent by friction and interlocking of the concrete against the vertical sides of the rectangular recesses. For better absorption of such tensile forces, the depth of the recesses in this case is preferably at least 10 mm, and more preferably at least 15 mm.

[0082] Preferably, one or more of the recesses have a dovetail shape, which improves the embedding in the concrete and allows tensile forces occurring perpendicular to the concrete surface, i.e. in the vertical direction of the web elements, to be absorbed more effectively.

[0083] SE / SE 240712WO

[0084] September 4, 2025 However, the inclined flanks of a dovetail shape can lead to a force acting along the longitudinal direction being partially redirected into a vertical force in the height direction of the web element, which results in a transverse tensile stress, particularly in the shear-stressed cross-section of the cam between the recesses.

[0085] In a further embodiment, one or more of the recesses have a rectangular shape with one or more undercuts. The one or more undercuts preferably each have an undercut surface that particularly preferably runs parallel to the upper surface of the web edge. In particular, the recess can have one or more undercuts on both sides. As with the dovetail shape, the undercuts achieve better embedding in the concrete, enabling it to better absorb tensile forces acting transversely to the concrete surface. However, compared to a dovetail shape, the rectangular shape with one or more undercuts does not, or only to a minimal extent, cause a redirection of a longitudinal force into a vertical force, thus reducing tensile stresses in this direction as well as transverse tensile stresses in the area of ​​the cams.

[0086] In a further embodiment, one or more of the recesses have a one-sided dovetail shape with a vertical and an inclined flank. Depending on the position of a recess in the longitudinal direction, shear forces in the longitudinal direction may occur only in one direction or be significantly stronger in one direction than in the opposite direction. The vertical flank of the recess is preferably oriented so that it is subjected to a greater load from the shear forces than the inclined flank. In this way, the deflection of the shear force into a vertical force and consequently the occurrence of transverse forces can be reduced compared to a dovetail shape with two sides, while the inclined flank ensures good embedding in the concrete with a vertical interlock.

[0087] SE / SE 240712WO

[0088] September 4, 2025. In particular, one or more of the recesses can be arranged along the longitudinal direction such that the inclined flank of a recess is closer to the center of the web element in its longitudinal direction than the vertical flank. In other words, the vertical flank of the cams located between the recesses is preferably closer to the center of the web element in its longitudinal direction than the inclined flank.

[0089] The recesses or the cams positioned between them can vary in size and shape along their longitudinal direction. Furthermore, curved, polygonal, or other profiles can be used that ensure sufficient interlocking with the concrete.

[0090] In one embodiment, a plate is provided on the underside of the stacking arrangement, which is preferably bonded to the underside. The plate preferably extends substantially over the entire underside of the stacking arrangement. Several plates arranged side by side are also conceivable, which together extend over the entire underside of the stacking arrangement. The one or more plates preferably extend in the stacking direction over several bottom chord elements and / or several web elements, preferably substantially over the entire extent of the stacking arrangement in the stacking direction.

[0091] The plate can reduce swelling and / or shrinkage of the stack arrangement in the stacking direction.

[0092] Unidirectionally glued wood components have the problem of swelling and shrinkage perpendicular to the grain. This can amount to approximately 10 mm per meter of cross-sectional width with a 4% change in wood moisture content. When using such prefabricated components for wood-concrete composite elements, this directional swelling and shrinkage can lead to problems when the building's moisture content changes, for example, due to changes in use or the transition between the heating and summer seasons. To mitigate these problems

[0093] SE / SE 240712WO

[0094] By September 4, 2025, wide construction joints can be incorporated between the components, which, however, can lead to aesthetic or structural problems, for example, regarding airtightness, moisture transport, or sound insulation, or require complex design considerations. Furthermore, such components are susceptible to undesirable deformations due to the practically non-expanding and non-shrinking nature of concrete. By using a panel, preferably bonded to the underside, such dimensional changes can be reduced to approximately 10%–20% compared to the dimensional changes without such a panel, thus facilitating the use of precast elements or timber-concrete composite components.

[0095] The panel is preferably a wood-based panel, for example an OSB panel or particleboard. An OSB panel is preferred because it can particularly well absorb forces and stresses from the stacking arrangement.

[0096] The panel can be decorated on the side facing away from the stacking arrangement, for example, with a decorative print. This eliminates the need for subsequent work to decorate the underside of a wood-concrete composite ceiling produced with the semi-finished element.

[0097] The board may be coated, particularly with resin, for example melamine. For instance, the board could be a melamine-coated particleboard. The board may also have a fire-retardant coating to improve the fire protection of the prefabricated element or the wood-concrete composite component.

[0098] Instead of or in addition to a wood-based panel, a plasterboard, in particular a gypsum building board or gypsum fire protection board, or a gypsum fiberboard (for example a Fermacell gypsum fiberboard, available from James Hardie plc, Dublin, Ireland) can also be used as the panel.

[0099] SE / SE 240712WO

[0100] September 4, 2025. Optionally, a fire-resistant panel can be used, for example, a fire-resistant OSB panel. Fire protection can be further improved by additionally or alternatively using a panel with a thickness of at least 20 mm.

[0101] In one embodiment, one or more of the lower chord elements have a longitudinal slot extending at least partially along the longitudinal direction, particularly starting from the top surface. Thus, the one or more of the lower chord elements are preferably each slotted at least partially along the longitudinal direction.

[0102] This embodiment is particularly advantageous if – according to a previously described embodiment – ​​a plate is provided on the underside of the stacking arrangement, and in particular, bonded to the underside. Such a plate prevents deformation of the stacking arrangement. However, in this case, especially with dimensional changes due to humidity fluctuations, high stresses can occur in the adhesive joint between the bottom chord elements and the web elements, which can lead to cracking. By longitudinally slotting one or more of the bottom chord elements, the resulting longitudinal slots allow for deformation, for example, due to drying, thereby reducing internal stresses and preventing cracking.

[0103] It is conceivable that each of the bottom chord elements has a longitudinal slot extending at least partially along its longitudinal direction. Furthermore, it is conceivable that only a subset of the bottom chord elements has a longitudinal slot extending at least partially along its longitudinal direction, for example, every second bottom chord element in the stacking direction.

[0104] SE / SE 240712WO

[0105] September 4, 2025. It is particularly preferred that one or more of the bottom chord elements are slotted along their entire length. In this way, the longitudinal slots allow for drying-related deformations and thus a stress reduction along the entire longitudinal direction. Furthermore, this facilitates the production of the longitudinal slots, e.g., by milling.

[0106] It is also conceivable to slot one or more of the bottom chord elements in sections, for example, only in certain areas. This can counteract any weakening of the bottom chord elements. Furthermore, it is conceivable that one or more of the bottom chord elements, especially those adjacent in the stacking direction, are slotted in different areas. In this way, the longitudinal slots allow for drying-related deformations and a reduction of stress over larger areas in the longitudinal direction, while at the same time preventing individual bottom chord elements from being weakened excessively.

[0107] One or more of the bottom chord elements can also have several longitudinal slots, for example longitudinal slots offset from each other in the longitudinal direction or, in the case of very thick bottom chord elements, longitudinal slots running side by side.

[0108] The longitudinal slots preferably have a width in the stacking direction of 1 - 8 mm, preferably 2 - 6 mm.

[0109] Preferably, the longitudinal slots extend at least halfway down the bottom chord elements, i.e., at least halfway up their height. This increases the stress-absorbing effect of the longitudinal slots, as this effect is greater the deeper the slots are.

[0110] It is also conceivable that the depth of a longitudinal slot extends through the entire height of the relevant bottom chord element, particularly if the longitudinal slot only covers a partial area in the longitudinal direction.

[0111] SE / SE 240712WO

[0112] 4 September 2025 bottom chord element extends and / or if a plate is provided on the underside of the stacking arrangement, in particular glued.

[0113] In corresponding embodiments of the method, a semi-finished part is provided in which one or more of the bottom flange elements have a longitudinal slot extending at least partially along the longitudinal direction. The one or more bottom flange elements are therefore preferably slotted at least partially along the longitudinal direction. The longitudinal slots are preferably introduced into the one or more bottom flange elements only after the elements have been bonded together, and more preferably, after the rest of the semi-finished part has been completed. This prevents the bottom flange elements from splitting completely, insufficient pressure from developing in the adhesive joint area lateral to the slots, or individual parts from failing to withstand the pressure during the production of the semi-finished part.

[0114] In one embodiment, one or more of the web elements have one or more transverse slots extending perpendicular to the longitudinal direction. This reduces or prevents curvature, particularly longitudinal curvature, of the semi-finished part in the longitudinal direction caused by changes in humidity.

[0115] Such longitudinal curvature of the semi-finished component can arise from differences in expansion between the flange elements and the web elements. These differences in expansion can occur when the flange and web elements experience changes in humidity, if they exhibit different swelling and shrinkage rates under the same humidity change, and / or if the web and flange elements exhibit different humidity changes and / or have the same or different swelling and shrinkage rates.

[0116] SE / SE 240712WO

[0117] September 4, 2025. This embodiment is particularly advantageous when the web elements are made of OSB panels. When OSB panels are used as web elements, they may absorb moisture when installed in the precast element, especially before the web elements are embedded in concrete during the production of a wood-concrete composite element, since OSB panels have a very low moisture content, particularly immediately after production. This can lead to expansion of the web elements in the area protruding from the bottom chord elements, as the web elements are not fixed by the bottom chord elements in this area. This can result in curvature of the precast element along the longitudinal direction of the stacking arrangement.

[0118] By having one or more of the web elements, preferably all web elements, one or more, preferably several, transverse slots extending transversely to the longitudinal direction, in particular in the stacking direction, such curvature can be reduced or completely avoided.

[0119] Preferably, the one or more of the web elements have several transverse slots distributed along their longitudinal direction. For example, the one or more web elements can have transverse slots extending at predetermined intervals along their longitudinal direction, particularly in the stacking direction.

[0120] The slots of different web elements, especially adjacent web elements, are preferably arranged offset from each other in the longitudinal direction. In this way, the semi-finished component or a wood-concrete composite component manufactured from it is weakened less by the transverse slots.

[0121] For example, it is conceivable that transverse slots of adjacent web elements, preferably transverse slots of at least three or more adjacent web elements, preferably of all web elements, are arranged on imaginary lines running obliquely to the longitudinal direction and to the stacking direction.

[0122] SE / SE 240712WO

[0123] The dates are September 4, 2025, wherein the imaginary lines preferably have an angle of >0° - 60°, in particular 5° - 60°, to the stacking direction. The corresponding transverse slots preferably lie on a respective line that forms an angle in the range <90° - 30°, in particular 85° - 30°, with the longitudinal direction.

[0124] For this purpose, the transverse slots of the respective web elements can in particular have the same distance to each other, wherein the first transverse slots of two adjacent web elements, seen from one end of the respective web element, are offset from each other by a predetermined distance.

[0125] The individual transverse slots can also run obliquely to the longitudinal direction and the stacking direction, particularly in the direction of the imaginary lines. Accordingly, the individual transverse slots can preferably have an angle to the stacking direction in the range >0° - 60°, particularly 5° - 60°.

[0126] In this way, the transverse slots can be made, for example, after the web elements have been embedded in the stacking arrangement, by guiding the stacking arrangement and a saw at an angle to both the longitudinal direction and the stacking direction. This simplifies manufacturing when the transverse slots are subsequently added to the web elements.

[0127] Furthermore, it is conceivable, for example, that the transverse slots of a first web element are arranged at a first distance in the longitudinal direction and the transverse slots of a second web element are arranged at a second distance in the longitudinal direction, different from the first distance.

[0128] Preferably, the least common multiple of the first and second distance is greater than 50%, more preferably greater than 100%, of the length of the semi-finished part in the longitudinal direction, or the first and second distance are incommensurate.

[0129] SE / SE 240712WO

[0130] September 4, 2025. However, it is also conceivable that the transverse slots of the web elements are aligned in the stacking direction. This also simplifies manufacturing if the transverse slots are subsequently added to the web elements.

[0131] The transverse slots preferably have a width in the range of 1 - 10 mm in the longitudinal direction of the stacking arrangement.

[0132] The depth of the transverse slots in the direction of the height of the web elements is preferably at least 50%, and particularly preferably at least 80%, of the areas projecting beyond the bottom chord elements. In particular, the transverse slots can extend over the entire area of ​​the one or more web elements projecting beyond the bottom chord elements, i.e., at least to the bottom chord elements.

[0133] The one or more web elements can also each consist of several panels arranged adjacent to each other in the longitudinal direction, in particular OSB panels, between which a joint with a joint width of preferably 1–10 mm is provided. The joints between the longitudinally adjacent panels then form the transverse slots of the web elements. In this case, the transverse slots extend in particular over the entire height of the web elements.

[0134] During the manufacturing of the timber-concrete composite element, the transverse slots are not fully embedded in the concrete layer. Therefore, the transverse slots in the timber-concrete composite element extend into the cavity. This distinguishes the transverse slots from the profiling provided on the web elements according to a previously described embodiment.

[0135] In one embodiment, the bottom chord elements and the concrete layer lie directly on top of each other. In another embodiment, a gap is provided between the bottom chord elements and the concrete layer.

[0136] SE / SE 240712WO

[0137] September 4, 2025. Accordingly, preferably only an upper part of the projecting areas of the web elements is embedded in concrete. The unembedded part of the projecting areas defines the distance between the bottom chord elements and the concrete layer. The space is arranged accordingly between the unembedded parts of the projecting areas.

[0138] In this way, a system analogous to I-beams is created, in which the top chord (compression chord) formed by the concrete layer and the bottom chord (tension chord) formed by the stacking arrangement or the bottom chord elements are formed by materials that are particularly advantageous for this purpose, namely the compression chord made of concrete and the bottom chord made of wood or wood-based material, whereby the spreading of the compression and tension chords as well as the transmission of the shear forces necessary for the load-bearing effect is carried out by the shear-stiff web elements made of wood-based material.

[0139] The gap created between the bottom chord elements and the concrete layer enables a structurally very efficient and material-saving overall design of the timber-concrete composite element. This design exhibits a significantly higher moment of inertia compared to timber-concrete composite elements where the timber bottom chord and concrete top chord are arranged directly above one another, particularly compared to cross-laminated timber (CLT) with a concrete layer poured on top, which is frequently used in timber-concrete composite elements. Specifically, the gap ensures that less load-bearing material, particularly only the web elements, is located in and near the neutral axis.

[0140] The space between the chords can be essentially empty, for example filled with air. This creates a cavity between the bottom chord elements and the concrete layer, through which, for example, one or more installation lines, such as power and / or data lines or utility lines like water and / or gas lines, and / or one or more other lines can be routed.

[0141] SE / SE 240712WO

[0142] On September 4, 2025, several empty conduits can be laid through the space, for example in the stacking direction and / or in the longitudinal direction.

[0143] In one embodiment, a filler material is arranged in the space, particularly in the form of a layer of filler material interrupted, especially by the web elements in the stacking direction. The filler material can occupy the entire space. However, it is also conceivable that the filler material occupies only a portion of the space. Preferably, the filler material forms a layer with a thickness of at least 20 mm, more preferably at least 50 mm.

[0144] In a corresponding embodiment, particularly of the semi-finished component, a filler material, especially in the form of a filler layer, is arranged between the projecting areas of the web elements. Specifically, the bottom chord elements and the web elements form channels on the top side of the stacked assembly in which the filler material can be arranged. The filler material is arranged between the bottom chords and a layer of concrete to be cast with the semi-finished component during the production of a timber-concrete composite element. In the semi-finished component, the filler material is preferably arranged such that an upper part of the projecting areas of the web elements extends beyond the filler material on the top side for embedding in a concrete layer.

[0145] The filler material can serve as a spacer, particularly a spacer layer, for pouring the concrete layer. Furthermore, the filler material can influence the properties of the timber-concrete composite component, especially its thermal and / or acoustic insulation properties. Accordingly, the filler material can be an insulating material, specifically a sound-insulating and / or thermal insulation filler.

[0146] When using the semi-prefabricated element or wood-concrete composite building element for insulated top floor ceilings or flat roofs, for example, the

[0147] SE / SE 240712WO

[0148] September 4, 2025: Using a heat-insulating filling material will reduce the construction height, as the roof insulation can be made thinner or even omitted entirely.

[0149] For example, the insulation material can be fibrous material, such as one or more of the following fiber materials: mineral fibers, such as glass fibers (for example as glass wool) or rock fibers (for example as rock wool), or organic fibers, such as wood fibers or cellulose fibers.

[0150] Furthermore, the insulation material can be a foaming material, for example mineral foam (e.g. Geolyth mineral foam, available from GEOLYTH Mineral Technologie GmbH, 4407 Dietach, Austria) or polymer foam, for example polyurethane foam (PUR foam).

[0151] The insulation material can be in the form of insulation mats, for example made of fibrous or foam material. Particularly with organic fibers such as wood fibers or cellulose fibers, the insulation material can also be blown into the cavity.

[0152] Furthermore, the filling material can be bulk material, for example one or more of the following: sand, gravel, crushed stone, recycled material such as construction waste, expanded clay, wood particles, especially wood particles impregnated with cement paste. This allows the mass of the wood-concrete composite component and thus its sound insulation properties to be increased.

[0153] The bulk material can be bound by a suitable binder, such as cement or polyurethane. This can improve insulation values ​​and / or simplify production.

[0154] SE / SE 240712WO

[0155] September 4, 2025. The bulk material can be further arranged in bags or tubes, for example made of textile or paper. This reduces the risk of the material shifting, for example during transport. It also simplifies the manufacturing process.

[0156] In addition to or as an alternative to the infill material, one or more installation lines, such as power and / or data lines or utility lines like water or gas lines, or one or more conduits for them, can run through the space between or between the protruding sections of the web elements, in particular through the channels formed by the protruding sections of the web elements and the chord elements. The one or more installation lines or one or more conduits can, for example, be arranged between the bottom chord elements and the infill material and / or be embedded in the infill material. Furthermore, the one or more conduits can run, for example, in the stacking direction and / or longitudinally.

[0157] The web elements can have one or more openings for laying one or more installation cables and / or conduits. This allows the installation cables and / or conduits to be laid in the stacking direction.

[0158] In one embodiment, one or more bulkhead elements are arranged between the projecting sections of the web elements. In particular, a bulkhead element preferably blocks a channel formed by a bottom chord element and two adjacent web elements in the longitudinal direction. An upper part of the projecting sections of the web elements preferably extends beyond the one or more web elements for embedding in concrete. It is also conceivable that one or more of the bulkhead elements are also embedded in concrete.

[0159] SE / SE 240712WO

[0160] September 4, 2025 With one or more bulkhead elements, particularly those located in the longitudinal direction at the ends of a channel formed by a bottom chord element and two adjacent web elements, especially in a closing grate area, the flow of grout into the channel can be limited when the timber-concrete composite element is laterally embedded in concrete, for example, to form a ring beam. Furthermore, the bulkhead elements can be used to position a filler material, such as bulk material, within the channel and prevent it from flowing out. This is particularly advantageous for securing timber-concrete composite elements during transport.

[0161] The one or more bulkhead elements are preferably made of wood. Alternatively, the one or more bulkhead elements can also be made of a wood-based material.

[0162] Further features and advantages of the semi-finished product, the wood-concrete composite element, its use and method will become apparent from the following description of exemplary embodiments, with reference to the attached drawing.

[0163] The drawing shows

[0164] Fig. aa-e shows a first embodiment of the semi-finished product, the timber-concrete composite element and the method for producing the timber-concrete composite element.

[0165] Figs. 2a-b show the use of the timber-concrete composite element from Figs. 1a-e for the production of a timber-concrete composite ceiling,

[0166] Fig. 3a-b shows a second embodiment of the semi-finished product and the wood-concrete composite element,

[0167] SE / SE 240712WO

[0168] September 4, 2025 Fig. 4a-c Web elements with shear cams from further embodiments of the semi-finished product and the timber-concrete composite element,

[0169] Fig. 5a-c shows a second embodiment of the method for producing the wood-concrete composite element,

[0170] Fig. 6a-b shows a further embodiment of the semi-finished product and the wood-concrete composite element and

[0171] Fig. 7 shows another embodiment of the semi-finished part.

[0172] Figures 1a-e show a first embodiment of the precast element, the method for producing the timber-concrete composite element, and the timber-concrete composite element itself. Figure 1a shows a schematic perspective view of the precast element without filler material. Figure 1b shows a schematic perspective view of the precast element after the addition of filler material and the placement of a reinforcing steel mesh. Figure 1c shows a perspective view of the finished timber-concrete composite element after the application and curing of the concrete layer. Figure 1d shows a schematic cross-sectional view of the finished timber-concrete composite element corresponding to the section plane labeled "Id" in Figure 1c, and Figure 1e shows a schematic longitudinal section view of the finished timber-concrete composite element corresponding to the section plane labeled "le" in Figure 1c.

[0173] The semi-finished part 104 has a stacking arrangement 106 comprising several bottom chord elements 108 made of wood and several web elements 110, wherein the several bottom chord elements 108 and the several web elements 110 are arranged alternately next to each other in a stacking direction (arrow 112) and glued together, so that the bottom chord elements 108 and web elements 110 together form a bottom 114 and an opposite top 116 of the stacking arrangement 106.

[0174] SE / SE 240712WO

[0175] September 4, 2025 The bottom chord elements 108 and the web elements 110 each extend in a longitudinal direction (arrow 118) transverse to the stacking direction 112 and are glued together in such a way that the bottom chord elements 108 are fully bonded, for example glued, with their side surfaces bordering the adjacent web elements 110.

[0176] The bottom chord elements 108 are made of solid structural timber, for example, from a single piece of solid structural timber extending along the entire longitudinal direction 118, or from several pieces joined one behind the other in the longitudinal direction 118 and transmitting tensile forces to each other, for example, by finger jointing. The bottom chord elements 108 have a width Bu in the range of 40–200 mm, preferably 60–150 mm, particularly 75–120 mm, in the stacking direction 112, and a height Hu in the range of 40–160 mm, preferably 50–100 mm, particularly 50–70 mm, in the vertical direction (arrow 120), i.e., in the direction from the bottom 114 to the top 116.

[0177] The web elements 110 are made of wood-based material, preferably OSB. On their underside, the web elements 110 are preferably flush with the bottom chord elements 108, so that the underside 114 formed by the web elements 110 and the bottom chord elements 108 is preferably flat. On their upper side 116, the web elements 110 have areas 122 (see Fig. Id) that project beyond the bottom chord elements 108. On an upper part 124 of the projecting areas 122, the web elements 110 are provided with a profile 126 in the form of a profiled web edge 128. The web edge 128 has a plurality of rectangular recesses 130 and cams 132 arranged between them, which enable a shear-force-transmitting connection to a concrete layer.

[0178] The web elements 110 have a width Bs in the range of 10 - 25 mm, preferably 12 - 20 mm, particularly 14 - 18 mm, in the stacking direction 112, and in the vertical direction

[0179] SE / SE 240712WO

[0180] 4 September 2025 (arrow 120) a height Hs which is 50 - 600 mm, preferably 200 - 500 mm, in particular 250 - 400 mm, greater than the height Hu, so that the web elements 110 on the top 116 project 50 - 600 mm, preferably 200 - 500 mm, in particular 250 - 400 mm, beyond the bottom chord elements 108.

[0181] The protruding areas 122 of the web elements 110 and the bottom chord elements 108 form several channels 134 running along the upper surface 116 in the longitudinal direction.

[0182] In the process for manufacturing a wood-concrete composite component, the semi-finished part 104 is first provided as shown in Fig. 1a.

[0183] Between the projecting areas 122 of the web elements 110, i.e., in the channels 134, filler material 140 is then arranged as shown in Fig. 1b, forming a filler material layer 142 interrupted by the web elements 110. The filler material layer 142 has a thickness d of at least 20 mm, preferably at least 50 mm. The upper part 124 of the web elements 110 projects beyond the filler material layer 142.

[0184] The filling material can be, for example, fibrous material such as glass wool or wood fibers, or foam material such as polyurethane foam. This can improve the thermal insulation properties. Alternatively, the filling material can also be loose fill, such as sand, gravel, crushed stone, or recycled material, which can increase the mass and thus improve the sound insulation properties.

[0185] In one or more of the channels 134, installation lines or conduits 172 can also be laid for this purpose. In particular, the installation lines or conduits can be pre-installed at the factory. Furthermore, it is conceivable to omit the fill material or to use less fill material in individual channels 134.

[0186] SE / SE 240712WO

[0187] September 4, 2025, to allow space for the subsequent installation of service lines or conduits. In order to also be able to lay the service lines or conduits in the stacking direction 112, openings 174 can be provided in the web elements 110 through which the service lines or conduits can be routed.

[0188] Subsequently, as shown in Fig. 1c, concrete is poured from above onto the filler material layer 142 and the upper parts 124 of the web elements 110 that project above the filler material layer, so that after the concrete has hardened, a concrete layer 102 (shown with dashed lines in Fig. 1c) is formed in which the upper parts 124 of the web elements 110 with the profile 126 are embedded. In this way, a shear-transmitting connection is created between the bottom chord elements 108 and the concrete layer 102 via the web elements 110. In this process, the filler material 140 serves as a spacer for pouring the concrete layer 102, so that a gap 144 remains between the bottom chord elements 108 and the concrete layer 102, in which the filler material 140 is arranged.

[0189] The concrete layer 102 can have reinforcement 160, in particular shrinkage reinforcement. To create the reinforcement, for example, a reinforcing steel mesh 161 can be placed on the web elements 110 before the concrete layer 102 is poured (see Fig. 1b). Additionally or alternatively, reinforcing bars, in particular made of steel, can also be placed through the recesses 130 of the web elements 110 in the stacking direction 112.

[0190] The reinforcement 160 of the timber-concrete composite elements 100 preferably projects beyond the concrete layer 102 in the longitudinal direction 118 (see Fig. 1). In this way, the projecting part 162 of the reinforcement 160 can later be embedded, for example, in a ring beam 164 (see Fig. 2b).

[0191] In the present embodiment, the wood-concrete composite element 100 is pre-produced as a wood-concrete composite prefabricated element.

[0192] SE / SE 240712WO

[0193] September 4, 2025. Figures 2a-b illustrate the use of such a timber-concrete composite element 100 for the production of a timber-concrete composite slab. Figure 2a shows a schematic cross-sectional view corresponding to Figure 1d, and Figure 2b shows a longitudinal section corresponding to Figure 1e.

[0194] To produce the timber-concrete composite slab 190, several identical timber-concrete composite elements 100 are arranged side by side in the stacking direction 112, for example, resting on a support 148 at their ends in the longitudinal direction. The stacking arrangement 106 of the timber-concrete composite elements 100 has bottom flange elements 109 on each of its outer sides in the stacking direction 112, which preferably project beyond the concrete layer 102 in the stacking direction 112. In this way, the bottom flange elements 109 on the outer sides in the stacking direction form a grout joint 150 at the joint of two timber-concrete composite elements 100, extending in the longitudinal direction 118. This joint can be filled with concrete to produce the timber-concrete composite slab 190, preferably with the insertion of joint reinforcement.For example, a joint sealing tape 152 can be arranged, in particular glued, between the butt-jointed lower chord elements 109 of the adjacent timber-concrete composite building elements 100.

[0195] The protruding part 162 of the reinforcement 160 can, for example, be embedded in a ring beam 164.

[0196] To prevent the liquid concrete from flowing into the channels 134 during the concreting of the ring beam 164, bulkhead elements 170 are arranged between the protruding sections 122, i.e., in the channels 134 (see Fig. 1 & 2b), which close off the channels 134 at their ends in the longitudinal direction 118. Further bulkhead elements 171 may be provided in the longitudinal direction, for example, to prevent the fill material from shifting during transport to the construction site.

[0197] SE / SE 240712WO

[0198] September 4, 2025. The precast element 104 can also be used directly for the production of the timber-concrete composite slab 190, without the prior production of timber-concrete precast components. For this purpose, several identical precast elements 104 without a concrete layer 102 can be arranged side by side, for example, resting on the support 148, and the filler material 140 can be placed in the channels 134. The concrete layer 102 can then be produced using cast-in-place concrete, with the joints being filled simultaneously, for example. In this way, the several adjacent precast elements 104 can be connected with a continuous concrete layer 102.

[0199] Figures 3a and 3b show a second embodiment of the semi-prefabricated element and the timber-concrete composite structure. Figure 3a shows a schematic cross-sectional view corresponding to Figure 1d, and Figure 2b shows a schematic longitudinal section corresponding to Figure 1e.

[0200] The semi-finished component 204 and the timber-concrete composite element 200 each have a similar structure to the semi-finished component 104 and the timber-concrete composite element 100. Corresponding components are provided with the same reference numerals, and reference is made to the above description of Fig. 1a-e.

[0201] The semi-finished component 204 and the timber-concrete composite element 200 differ from the semi-finished component 104 and the timber-concrete composite element 100, respectively, in that a panel 280 is arranged on the underside 114 of the stacking arrangement 106 and is bonded to the underside 114 over its entire surface. The panel 280 is a wood-based panel, preferably OSB. The panel 280 can distribute forces occurring in the stacking arrangement 106. Furthermore, the panel can reduce local swelling or warping of the stacking arrangement 106 due to moisture.

[0202] SE / SE 240712WO

[0203] September 4, 2025. The panel 280 preferably has a thickness of at least 20 mm and / or comprises fire-retardant additives or a fire-retardant coating. In this way, the fire protection of the semi-finished component 204 or the wood-concrete composite element 200 can be improved.

[0204] The panel 280 can have a decoration and / or a resin layer on the side facing away from the stacking arrangement 106, which forms the lower visible side 282 of the semi-finished part 204 or wood-concrete composite element 200.

[0205] Figures 4a-c show web elements of further embodiments of the semi-finished part. The web elements 310, 310' and 310" differ from the web element 110 of the semi-finished part 104 in that the recesses 330, 330' and 330" and cams 332, 332' and 332" of the profiling 326, 326' and 326" of the web edge 128 are designed differently.

[0206] In Fig. 4a, the recesses 330 and cams 332 are dovetail-shaped. The upper surfaces of the cams 332 and recesses 330 can, for example, have a length LN and LA, respectively, of 50 mm in the direction of extension and a height HN and depth, respectively, of 20 mm. The inclined side surfaces 333 (flanks) between the cams 332 and recesses 330 can, for example, have an angle α of 15° to the vertical direction 120. Such a profile 326 allows for an even better bond to the concrete layer, particularly under tensile forces perpendicular to the plane of the concrete layer.

[0207] In Fig. 4b, the recesses 330' are rectangular with undercuts 331 on both sides. Each undercut 331 has an undercut surface 335 parallel to the top surface of the cams 332'. The top surfaces of the cams 332' and recesses 330' can, for example, have a length LN and LA, respectively, of 50 mm in the direction of extension and a height HN and depth of 20 mm, respectively. Such a profile 326' can also be used to create a

[0208] SE / SE 240712WO

[0209] September 4, 2025, good connection to the concrete layer is achieved even under tensile forces perpendicular to the plane of the concrete layer, while a deflection of forces from longitudinal to vertical direction, which can occur with the inclined side surfaces 333 from Fig. 4a, is avoided.

[0210] In Fig. 4c, the recesses 330" and cams 332" are designed as a one-sided dovetail and accordingly have a vertical side surface 336 and an inclined side surface 337. The individual cams 332" are arranged such that the vertical side surface 336 of each cam 332' faces the center of the web element 310" in the longitudinal direction, and the inclined side surface 337 faces away from the center. With such a profile 326", a good connection to the concrete layer can also be achieved even under tensile forces transverse to the plane of the concrete layer. The arrangement of the vertical side surfaces 336 in Fig. 4c prevents the deflection of forces from the longitudinal to the vertical direction away from the typical force direction.

[0211] The web elements 310, 310' or 310" can in particular be used instead of the web element 110 of the semi-finished part 104 from Fig. 1a-e or Fig. 3a-b.

[0212] Figures 5a-c show a second embodiment of the method for producing the wood-concrete composite element in schematic cross-sectional representation.

[0213] To manufacture the timber-concrete composite element 400 as a precast timber-concrete composite component, a semi-finished component 404 is provided, as shown in Fig. 5a. This semi-finished component can, for example, be designed like the semi-finished component from Figs. 1a-e. Corresponding components are designated with the same reference numerals in Figs. 1a-e and 5a-c, and reference is made to the description of Figs. 1a-e above. Alternatively, the semi-finished component 404 can also be designed like the semi-finished component 204 from Figs. 3a-b. Furthermore, as also shown in Fig. 5a, concrete 401 is poured into a concrete layer mold 490.

[0214] SE / SE 240712WO

[0215] September 4, 2025. The semi-finished part 404 is then oriented downwards as shown in Fig. 4b with the protruding areas 122 of the web elements 110 facing downwards and immersed in the uncured concrete 401 in the concrete layer mold 490 with at least the upper part 124 of the protruding areas 122 of the web elements. Alternatively, the semi-finished part 404 can first be arranged in the concrete layer mold with the upper part of the protruding areas of the web elements facing downwards and then the concrete 401 can be added.

[0216] After the concrete 401 has hardened, a concrete layer 102 has formed, into which the upper part of the protruding sections of the web elements is embedded. The finished wood-concrete composite element 400 can be removed from the concrete layer mold 490.

[0217] The previously described method allows the size of the gap 144 to be adjusted independently of the thickness of the filler material. Furthermore, filler material can also be introduced into the channels 134 or gaps 144 only after the concrete layer 102 has hardened.

[0218] Figures 6a and 6b show a further embodiment of the semi-prefabricated element and the timber-concrete composite structure. Figure 6a shows a schematic cross-sectional view corresponding to Figure 3a, and Figure 6b shows a schematic longitudinal section corresponding to the section plane labeled "Vlb" in Figure 6a.

[0219] The semi-finished component 504 and the timber-concrete composite element 500 each have a similar structure to the semi-finished component 204 and the timber-concrete composite element 200. Corresponding components are provided with the same reference numerals, and reference is made to the description in Figs. 3a-b above.

[0220] SE / SE 240712WO

[0221] September 4, 2025. The semi-finished component 504 and the timber-concrete composite element 500 differ from the semi-finished component 204 and the timber-concrete composite element 200 only in that every second of the bottom chord elements 108 has a longitudinal slot 580 extending along the longitudinal direction 118. The longitudinal slots 580 have a width in the stacking direction of 2–6 mm and a depth of slightly over 50% of the height of the bottom chord elements 108. In the present embodiment, the longitudinal slots 580 extend over the entire length of the bottom chord elements 108. Alternatively, it is conceivable that the longitudinal slots 580 extend only over a portion of the length of the respective bottom chord elements 108.

[0222] The longitudinal slots 580 reduce stresses at the adhesive joint between the bottom chord elements 108 and the web elements 110, especially in the case of moisture-related dimensional changes.

[0223] Fig. 7 shows a further embodiment of the semi-finished part in a perspective view corresponding to Fig. 1a. The semi-finished part 604 has a similar structure to the semi-finished part 104. Corresponding components are provided with the same reference numerals, and reference is made to the description of Figs. 1a-e above.

[0224] The semi-finished part 604 differs from the semi-finished part 104 only in that the web elements 110 each have several transverse slots 682 extending transversely to the longitudinal direction 118. The transverse slots 682 of a web element 110 are each arranged at an equal distance A from one another along the longitudinal extent of the web element 110. In the present embodiment, the transverse slots 682 of adjacent web elements 110 are each offset from one another by approximately 50% of this distance, so that the transverse slots 682 of adjacent web elements 110 are arranged offset from one another. In this way, the transverse slots 682 of the web elements 110 are each inclined to the longitudinal direction 118.

[0225] SE / SE 240712WO

[0226] On September 4, 2025, the imaginary lines L run towards the stacking direction 112, which in the present embodiment have an angle of 45° to the stacking direction 112. The individual transverse slots 682 themselves were introduced in the present embodiment before the web elements 110 were embedded in the stacking arrangement 106 and each run in the stacking direction 112. Alternatively, the transverse slots 682 can also be introduced after the embedding in the stacking arrangement 106 by moving a saw in the direction of the lines L, so that the transverse slots 682 themselves then also run in the direction of these lines.

[0227] It is also conceivable that the distances between the transverse slots 682 of two adjacent web elements 110 differ from each other, preferably are incommensurate with each other, in order to avoid transverse slots arranged at the same location in the longitudinal direction.

[0228] The transverse slots 682 reduce or prevent the curvature of the semi-finished part 604 when moisture is absorbed by the web elements 110.

[0229] Reference symbol list:

[0230] 100, 200, 400, 500 wood-concrete composite building element

[0231] 102 concrete layer

[0232] 104, 204, 404, 504, 604 Semi-finished part

[0233] 106 Stack arrangement

[0234] 108, 109 Lower chord element

[0235] 110, 310, 310', 310" bridge element

[0236] 112 Stacking direction

[0237] 114 Underside of the stack arrangement

[0238] 116 Top of the stack arrangement

[0239] 118 Longitudinal direction

[0240] 120 Altitude

[0241] 122 protruding area of ​​the web element

[0242] SE / SE 240712WO

[0243] September 4, 2025 124 upper part of the protruding area

[0244] 126, 326, 326', 326" Profiling

[0245] 128 Stegrand

[0246] 130, 330, 330', 330" recess

[0247] 132, 332, 332', 332" cam

[0248] Channel 134

[0249] 140 packing material

[0250] 142 Filler layer

[0251] 144 space

[0252] 148 bearings

[0253] 150 Grouting joint

[0254] 152 Joint sealing tape

[0255] 160 reinforcement

[0256] 161 Reinforcing steel mat

[0257] 162 protruding part of the reinforcement

[0258] 164 Ring anchor

[0259] 170, 171 bulkhead element

[0260] 172 empty conduit

[0261] 174 Opening

[0262] 190 wood-concrete composite ceiling

[0263] 280 plate

[0264] 282 lower visible side

[0265] 331 undercuts

[0266] 333, 336, 337 side surface

[0267] 335 Undercut area

[0268] 401 Concrete

[0269] 490 Form

[0270] 580 longitudinal slots

[0271] 682 Cross slot

[0272] SE / SE 240712WO

[0273] September 4, 2025

Claims

4. September 2025 P a t e n t a n s p r ü c h e 1. Semi-finished component (104, 204, 404) for the production of a timber-concrete composite structural element (100, 200, 400), in particular a timber-concrete composite slab or a timber-concrete composite precast element, with a stacking arrangement (106) comprising several bottom chord elements (108, 109) made of wood and several web elements (110, 310), wherein the several bottom chord elements (108, 109) and the several web elements (110, 310) are arranged side by side in a stacking direction (112) and glued together, such that the bottom chord elements (108, 109) and the web elements (110, 310) together form a bottom (114) and an opposite top (116) of the stacking arrangement (112), wherein the web elements (110, 310) are connected at the top (116) via the Lower chord elements (108, 109) have projecting areas (122) for their at least partial embedding in concrete, characterized in that the several lower chord elements (108, 109) and the several web elements (110,310) are arranged alternately next to each other in the stacking direction (112) and that the web elements (110, 310) are made of wood-based material.

2. Semi-finished product according to claim 1, characterized in that the lower chord elements (108, 109) are made of structural timber, preferably of longitudinally bonded, in particular finger-jointed, structural timber.

3. Semi-finished product according to claim 1 or 2, characterized in that the lower chord elements (108, 109) are in Stacking direction (112) have a width in the range of 40 - 200 mm, preferably 60 - 150 mm, in particular 75 - 120 mm and / or a height in the range of 40 - 160 mm, preferably 50 - 100 mm, in particular 50 - 70 mm.

4. Semi-finished product according to one of claims 1 to 3, characterized in that the wood material of the web elements (110, 310) contains wood chips, in particular the web elements (110, 310) are formed from chipboard or OSB boards.

5. Semi-finished product according to one of claims 1 to 4, characterized in that the web elements (110, 310) in the stacking direction (112) have a width in the range of 10 - 25 mm, preferably 12 - 20 mm, in particular 14 - 18 mm, and / or the areas (122) of the web elements (110, 310) projecting on the top (116) over the bottom chord elements (108, 109) have a height in the range of 20 - 600 mm, preferably 200 - 500 mm, in particular 250 - 400 mm.

6. Semi-finished part according to one of claims 1 to 5, characterized in that the projecting areas (122) of the web elements (110, 310) are provided with a profile (126, 326, 326', 326"), in particular having a profiled web edge (128).

7. Semi-finished part according to one of claims 1 to 6, characterized in that a plate (280) is provided on the underside (114) of the stacking arrangement (106), which is in particular bonded to the underside (114).

8. Semi-finished part according to one of claims 1 to 7, characterized in that one or more of the lower chord elements (108, 109) have a respective longitudinal slot extending at least partially along the longitudinal extension direction (118). SE / SE 240712WO September 4, 2025 9. Semi-finished part according to one of claims 1 to 8, characterized in that one or more of the web elements (110, 310) have one or more transverse slots extending transversely to the longitudinal direction (118), in particular in the stacking direction (112).

10. Semi-finished part according to one of claims 1 to 9, characterized in that a filling material (140) is arranged between the protruding areas (122) of the web elements (110, 310) and / or one or more installation lines or empty conduits (172) run for this purpose.

11. Semi-finished part according to one of claims 1 to 10, characterized in that one or more bulkhead elements (170, 171) are arranged between the projecting areas (122) of the web elements (110, 310).

12. Semi-finished product according to one of claims 1 to 11, characterized in that the stacking arrangement (106) has a width in the stacking direction (112) in the range of 0.5 - 2.5 m, preferably 0.75 - 2 m, in particular 1 - 1.5 m, and / or a length in the longitudinal extension direction (118) in the range of 1 - 15 m, preferably 2.5 - 10 m, in particular 5 - 8.5 m.

13. Timber-concrete composite element (100, 200, 400), in particular timber-concrete composite slab or timber-concrete composite precast element, comprising a semi-precast element (104, 204, 404) according to one of claims 1 to 12 and comprising a concrete layer (102), wherein the protruding areas (122) of the web elements (110, 310) are embedded in the concrete layer (102) at least in an upper part (124). SE / SE 240712WO September 4, 2025 14. Timber-concrete composite element according to claim 13, characterized in that a space (144) is provided between the bottom chord elements (108, 109) and the concrete layer (102), wherein a filling material (140) and / or one or more installation lines or empty conduits (172) preferably run through the space (144) in the space (144).

15. Use of a semi-finished product (104, 204, 404) according to one of claims 1 to 12 for the production of a wood-concrete composite building element (100, 200, 400), in particular according to one of claims 13 or 14.

16. Use according to claim 15, characterized in that the protruding areas (122) of the web elements (110, 310) are at least partially embedded in concrete.

17. Method for producing a wood-concrete composite element (100, 200, 400) according to claim 13 or 14, wherein a semi-finished part (104, 204, 404) according to one of claims 1 to 12 is provided, wherein at least an upper part (124) of the projecting areas (122) of the web elements (110, 310) of the semi-finished part (104, 204, 404) is embedded in uncured concrete, so that when the concrete cures a concrete layer (102) is formed in which at least the upper part (124) of the projecting areas (122) of the web elements (110, 310) is embedded, and wherein optionally a filler material and / or one or more installation lines or conduits for this purpose are arranged between the projecting areas (122).

18. Method according to claim 17, characterized in that SE / SE 240712WO September 4, 2025 that the semi-finished element with the protruding areas (122) of the web elements (110, 310) is arranged upwards and the uncured concrete, in particular as cast-in-place concrete, is applied to the timber-concrete composite element (100, 200, 400) or - that the semi-finished element with the protruding areas (112) of the web elements (110, 310) is oriented downwards and is immersed with at least the upper part of the protruding areas of the web elements in uncured concrete. SE / SE 240712WO September 4, 2025

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