DE102020201254A1 - Wood-prestressed concrete composite panel and process for their production - Google Patents

Abstract

A wood-prestressed concrete composite panel, in particular for use as a building ceiling panel, comprises - a lower, planar wood layer (4) made of a wood material, - an upper prestressed concrete layer (1) curved upwards vertically to the spanwise direction (SWR), which is connected to the Timber layer (4) is connected, and - an adhesive layer (5) that bridges the curvature gap (KS) formed by the curvature of the prestressed concrete layer (1) and thickened from the transverse edges (9, 10) to the center of the span (SWM) of the prestressed concrete layer (1) between prestressed concrete layer (1) and wood layer (4) for the permanent connection of these two layers.

Description

The invention relates to a wood-prestressed concrete composite panel with the features specified in the preamble of claim 1 and a method for its production.

With regard to ecological aspects in construction, the use of wood as a material has been increasing significantly for some time. Nonetheless, concrete elements also have advantages for their part, such as excellent soundproofing properties due to their high mass and the possibility of using prestressed concrete to achieve high spans.

In order to use the advantages of both building materials, composite elements made of a wood and concrete layer are, for example, from the DE 44 20 175 A1 or the post-published DE 10 2019 215 009 A1 known to the applicant. In these previously known composite panels, the wood layer is permanently connected to the non-prestressed concrete layer by direct grouting of the concrete with recesses in the wood layer that transmit shear forces. In this prior art, however, there is no provision for the concrete layer to be filled as a prestressed concrete layer, since on the one hand it would then practically not be possible to cast the concrete with the wood layer with the simultaneous tensioning reinforcement. On the other hand, a composite panel jointly pre-stressed with its layers would be curved concavely on the underside, which would result in a curved ceiling soffit that is unacceptable for residential construction.

The invention is accordingly based on the object of creating a wood-prestressed concrete composite panel and a method for its production which, while avoiding the disadvantages discussed above, enables a component with a large span and a flat wooden ceiling soffit.

In terms of product technology, according to the characterizing part of claim 1, this object is achieved in that the permanent connection between the wood layer and the prestressed concrete layer is achieved by a layer of adhesive that thickens the curvature gap formed by the curvature of the prestressed concrete layer from the transverse wheels to the center of the span bridged.

The wood-prestressed concrete composite panel produced in this way remains absolutely flat on its underside despite the prestressing and curvature of the prestressed concrete layer, which also provides a visually appealing wood appearance. At the same time, due to the use of prestressed concrete, the composite panel can have a large span. Finally, the existing curvature of the upper side of the prestressed concrete layer, due to its prestressing, does not play a disruptive role from a structural point of view, since a screed layer is usually applied there for the floor covering that can be stripped flat.

• - Bereitstellen der planen Holzlage auf einer planen Unterlage,
• - Aufbringen der Klebstoffschicht aus einem pastösen Klebstoff auf die Oberseite der Holzlage derart, dass die vertikale Dicke der Klebstoffschicht von den Längsrändern der Holzlage zur Spannweitenmitte entsprechend der Krümmung der Spannbetonlage zunimmt,
• - Auflegen einer vorgefertigten Spannbetonplatte als Spannbetonlage mit ihrer konkav gekrümmten Unterseite auf die Oberfläche der Klebstoffschicht, und
• - Aushärtenlassen der Klebstoffschicht unter dauerhafter Verbindung der Holzlage mit der Spannbetonlage.

From a procedural point of view, the object of the invention explained above is achieved according to the characterizing part of claim 7 by the following process steps:

• - Provision of the flat wood layer on a flat base,
• - Application of the adhesive layer made of a pasty adhesive on the upper side of the wood layer in such a way that the vertical thickness of the adhesive layer increases from the longitudinal edges of the wood layer to the center of the span according to the curvature of the prestressed concrete layer,
• - placing a prefabricated prestressed concrete slab as a prestressed concrete layer with its concavely curved underside on the surface of the adhesive layer, and
• - Allowing the adhesive layer to harden with a permanent bond between the wood layer and the prestressed concrete layer.

In the dependent claims, preferred developments of the wood-prestressed concrete composite panel and their manufacturing method are specified. The thickness values for the course of the adhesive layer have a vertical thickness between a minimum of 1 mm, preferably 1 to 2 mm, in the area of the transverse edges up to the centimeter area, preferably about 2 cm in the center of the span for an exemplary span of the prestressed concrete composite slab from 6 to 8 m proved to be advantageous.

The wood layer can be formed from a transversely glued laminated wood panel, i.e. it is based on a material that has been tried and tested in construction, is robust and warp-free, yet has an attractive aesthetic appearance.

In terms of laying technology, an optionally provided overhang of the wood layer beyond the longitudinal edges of the prestressed concrete layer in the transverse direction has the advantage that a grouting joint is formed between these longitudinal edges between two adjacent prestressed concrete slabs, which accommodate a conventional turnbuckle between the two slabs for bracing them and then can be shed. A ceiling composed of wood-prestressed concrete composite panels according to the invention then acts statically as a continuous pane.

A 2- Component reaction resin adhesive based on polyurethane highlighted as it is commercially available as tile adhesive. Accordingly, the wood-prestressed concrete composite panel according to the invention can consistently be produced with commercially available components and thus economically justifiable.

Due to the type of adhesive mentioned above, the adhesive layer can be allowed to harden within a period of 12 to 48 hours, which is also justifiable in terms of production technology.

Finally, for an optimal production result, it is advantageous if the course of the thickness of the adhesive layer is adapted as well as possible to the concave course of curvature of the prestressed concrete slab forming the prestressed concrete layer. For this purpose, as a preferred preliminary production step, the concave curvature of the prestressed concrete layer can be determined by a preceding simulation test by placing the prestressed concrete slab on a simulated wall support. The distance between the underside of the panel in the center of the span and the horizontal connecting line between the support points corresponds to the required thickness of the adhesive layer in this area.

• 1 eine perspektivische Ansicht einer Holz-Spannbeton-Verbundplatte,
• 2 eine Ansicht der Längsseite der Holz-Spannbeton-Verbundplatte gemäß 1, und
• 3 einen Vertikalschnitt der Holz-Spannbeton-Verbundplatte gemäß Schnittlinie III-III nach 2

Further features, details and advantages of the invention emerge from the following description of an exemplary embodiment with reference to the accompanying drawings. Show it:

• 1 a perspective view of a wood-prestressed concrete composite panel,
• 2 a view of the long side of the wood-prestressed concrete composite panel according to 1 , and
• 3 a vertical section of the wood-prestressed concrete composite slab according to section line III-III 2

As is clear from the drawings, the wood-prestressed concrete composite panel shown has an upper prestressed concrete layer as a load-bearing element 1 in the form of a conventionally manufactured and designed prestressed concrete slab. In it - like in particular from 1 and 3 emerges - in the span direction SWR continuous hollow channels 2 created. Furthermore, in 3 the tension ropes 3 drawn in for the tensile reinforcement of the slab. The reinforcement grids, which are also regularly provided for concrete slabs, are omitted in this illustration for the sake of clarity.

The lower layer of the wood-prestressed concrete composite panel is made up of a flat layer of wood 4th formed from a cross-glued laminated wood panel. To connect the two layers 1 , 4th is an adhesive layer 5 provided in between, which consists of a 2-component reaction resin adhesive based on polyurethane. For example, a commercially available reaction resin adhesive with the trade name “codex Fliesopur” from Uzin Utz AG, DE-89079 Ulm, can be used.

How out 1 and 2 becomes clear, is the prestressed concrete layer 1 curved upwards so that its top 6th in the spanwise direction SWR convex, their underside 7th is concave. The thus formed curvature gap KS between the underside 7th and the flat top 8th is due to the appropriately adjusted vertical thickness D of the adhesive layer 5 bridged over the entire surface in relation to the plate surface. For this purpose, the vertical thickness D has at the transverse edges 9 , 10 the composite slab has a dimension of about 1 to 2 mm, which is the case with a typical span SW of the prestressed concrete layer 1 increases from 7 m to the center of the span width SWM to, for example, 2 cm.

Like in particular from 3 shows the wood layer 4th over the longitudinal edges 12th , 13th the prestressed concrete layer 1 a few centimeters in the transverse direction, so that when wood-prestressed concrete composite panels are positioned next to each other, between their longitudinal edges 12th , 13th a grouting joint 14th remains open. From the longitudinal edges 12th , 13th in the transverse direction in the grouting joint 14th protruding anchoring irons 15th can be connected with tensile strength via turnbuckles (not shown), after which the casting joint 14th can be closed by a suitable casting material.

• Die die Spannbetonlage 1 bildende Spannbetonplatte wird in üblicher Weise vorgefertigt, was keiner näheren Erörterung bedarf. Um deren Durchbiegung für die Dickenauslegung der späteren Klebstoffschicht 5 zu ermitteln, wird eine solche vorgefertigte Spannbetonplatte in einem vorgelagerten Simulationsversuch auf ein simuliertes Wandauflager gesetzt, sodass sich die Platte aufgrund ihres Eigengewichtes aus der vorspannungsbedingten Durchbiegung ein gewisses Maß streckt. In diesem Zustand wird der Abstand der Unterseite 7 der Platte von einer horizontalen Linie zwischen den beiden Wandauflagern gemessen, welches Maß die vertikale Dicke D der späteren Klebstoffschicht 5 bestimmt.

The production of the wood-prestressed concrete composite panel shown in the drawings is to be explained as follows:

• The pre-stressed concrete layer 1 prestressed concrete slab is prefabricated in the usual way, which requires no further discussion. About their deflection for the thickness design of the later adhesive layer 5 To determine this, such a prefabricated prestressed concrete slab is placed on a simulated wall support in a preceding simulation test, so that the slab stretches to a certain extent due to its own weight from the bending caused by the prestressing. In this state, the distance becomes the bottom 7th of the panel measured from a horizontal line between the two wall supports, which measure the vertical thickness D of the later adhesive layer 5 definitely.

The then following production - usually at least a small series production - beginning by placing a prepared plane layer of wood 4th on a flat surface 16 - see below 2 - is placed. After that, paste-like adhesive is used to form the adhesive layer 5 with the thickness profile described above on the wood layer 4th applied manually or by an appropriate automatic application device. The Prefabricated prestressed concrete slab to form the prestressed concrete layer 1 with their curved underside 7th on the wood layer 4th with the adhesive layer 5 be placed from above, whereby the prestressed concrete layer is due to its own weight 1 again something stretches into the configuration determined in the preliminary test and thus an intimate connection between the prestressed concrete layer 1 , Adhesive layer 5 and wood layer 4th is achieved. This is how the curing time of the adhesive layer is positioned 5 about 12 to 48 Wait hours, which will allow the adhesive to cure. The wood-prestressed concrete composite panel can then be maneuvered by a crane with the help of the anchoring iron 15th be taken to a warehouse or suitable means of transport.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 4420175 A1 [0003]
• DE 102019215009 A1 [0003]

Claims (10)

Wood-prestressed concrete composite panel, in particular for use as a building ceiling panel, comprising - a lower, planar wood layer (4) made of a wood material, - an upper prestressed concrete layer (1) curved upwards vertically to the span direction (SWR), which joins the wood layer (4) is connected, characterized by - an adhesive layer (5) bridging the curvature gap (KS) formed by the curvature of the prestressed concrete layer (1) and thickening from the transverse edges (9, 10) to the center of the span (SWM) of the prestressed concrete layer (1) between prestressed concrete layer (1) and wood layer (4) for the permanent connection of these two layers. Wood-prestressed concrete composite panel according to Claim 1 , characterized in that the vertical thickness (D) of the adhesive layer (5) varies between a minimum of 1 mm in the area of the transverse edges (9, 10) to the centimeter area in the center of the span (SWM). Wood-prestressed concrete composite panel according to Claim 1 2, characterized in that the vertical thickness (D) of the adhesive layer (5), in particular with a span (SW) of the wood-prestressed concrete composite panel of 6 - 8 m, in the area of the transverse edges (9, 10) 1 to 2 mm and in the center of the span (SWM) is about 2 cm. Wood-prestressed concrete composite panel according to one of the preceding claims, characterized in that the wood layer (4) is formed from a transversely glued laminated wood panel. Wood-prestressed concrete composite panel according to one of the preceding claims, characterized in that the wood layer (4) projects beyond the longitudinal edges (9, 10) of the prestressed concrete layer (1) in the transverse direction. Wood-prestressed concrete composite panel according to one of the preceding claims, characterized in that the adhesive layer (5) is formed from a 2-component reaction resin adhesive based on polyurethane. Process for producing a wood-prestressed concrete composite panel according to one of the preceding claims, characterized by the following process steps: - providing the planar wood layer (4) on a planar base (16), - applying the adhesive layer (5) made of a pasty adhesive to the top (8) of the wood layer (4) in such a way that the vertical thickness (D) of the adhesive layer (5) increases from the transverse edges (9, 10) of the prestressed concrete layer (1) to the center of the span (SWM) according to the curvature of the prestressed concrete layer (1), - Laying a prefabricated prestressed concrete slab as a prestressed concrete layer (1) with its concavely curved underside (7) on the surface of the adhesive layer (5), and - Allowing the adhesive layer (5) to harden while permanently bonding the wood layer (4) to the prestressed concrete layer (1). Procedure according to Claim 7 , characterized in that the adhesive layer (5) has a vertical thickness (D) between a minimum of 1 mm, preferably 1-2 mm in the area of the transverse edges (9, 10), down to the centimeter area, preferably up to about 2 cm Center of span (SWM) is applied. Procedure according to Claim 7 or 8th , characterized in that the adhesive layer (5) is allowed to harden over a period of time between 12 and 48 hours. Method according to one of the Claims 7 until 9 , characterized in that the concave curvature of the prestressed concrete slab forming the prestressed concrete layer (1) is determined in order to determine the required thickness profile of the adhesive layer (5) in the spanwise direction (SWR) by placing the prestressed concrete slab on a simulated wall support.

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