EP3960950A1

EP3960950A1 - Wooden pillar-beam structure equipped with glass elements, and method for forming wooden pillar-beam structure equipped with glass elements

Info

Publication number: EP3960950A1
Application number: EP21194256.0A
Authority: EP
Inventors: Harri ISOMÄKI
Original assignee: Primapoli Ltd Oy
Current assignee: Primapoli Ltd Oy
Priority date: 2020-09-01
Filing date: 2021-09-01
Publication date: 2022-03-02
Also published as: FI20205851A1; FI20205851A

Abstract

The invention relates to a wooden pillar-beam structure equipped with glass elements. The pillar-beam structure comprises essentially vertical wooden pillars (10) belonging to a load-bearing structure (13) of a building (29) as well as glass elements (11) . In the pillar-beam structure, a glass element (11) is supported to a wooden pillar (10). The glass element (11) is attached by means of an adhesive connection (16). The invention also relates to a method for forming a wooden pillar-beam structure equipped with glass elements.

Description

The invention relates to a wooden pillar-beam structure equipped with glass elements, which comprises essentially vertical wooden pillars belonging to a load-bearing structure of a building as well as glass elements, wherein a glass element is supported to a wooden pillar in the pillar-beam structure. The invention also relates to a method for forming a wooden pillar-beam structure equipped with glass elements.
A wooden pillar-beam structure is used as part of a building, in particular a log building or a building constructed with wooden beams, for example, in order to form a glass facade. A pillar-beam structure can also form part of a building or structure made of another material. Essentially vertical wooden pillars support a roof structure of the building and, when necessary, crossbeams are used. Glass elements are installed in the openings of the resulting lattice structure, whereby a bright yet thermally insulating wall is formed. A single glass element can be several square metres in size.
As the size and the number of glass elements increase, it becomes necessary to use steel beams, at least in part, in order to provide the lattice structure with an adequate stiffness. A steel beam is arranged, for instance, as a support column to which the lattice structure is attached. This entails higher costs while the basic idea of building with wood is at least partially watered down. It also becomes necessary to use a special attachment profile, which is first attached to a wooden pillar and to which the glass elements are attached by means of hooks. One such known structure comprising wooden pillars is disclosed in the publication WO2019/112450A1 . Here too, a special profile, with which separate fasteners interlock, is attached to a wooden pillar. In practice, supporting glass elements by means of fasteners is local and insecure. Attachment profiles also require a supporting attachment abutment, which often leads to the use of steel beams instead of wooden pillars.
The object of the invention is to provide a novel wooden pillar-beam structure equipped with glass elements which is more robust than before and with which it is possible to realize a more extensive glazing than in the past in a pillar-beam structure without steel beams or other steel structures. The characteristic features of the pillar-beam structure according to the invention are indicated in the attached claim 1. A further object of the invention is to provide a novel method for manufacturing a wooden pillar-beam structure equipped with glass elements which is simpler than in the past and by means of which the resulting pillar-beam structure exhibits a greater stiffness than before. The characteristic features of the method according to the invention are indicated in the attached claim 12. In the pillar-beam structure according to the invention, the glass elements are attached in a new and surprising manner. Installation is simple and the pillar-beam structure can be rendered stiff and compact easily. Moreover, steel structures are not necessary while cold bridges are simultaneously prevented. At least part of the pillar-beam structure can be prefabricated in factory conditions, which expedites installation and ensures a good quality. Moreover, the stiffness of the pillar-beam structure can be further increased without auxiliary structures remaining in view.
The invention is described in the following in detail with reference to the attached drawings showing embodiments of the invention, wherein

Figure 1: shows schematically a pillar-beam structure according to the invention,
Figure 2: shows a cross-section of a pillar-beam structure according to the invention,
Figure 3: shows a cross-section of a variant of a pillar-beam structure according to the invention during an instalment step,
Figure 4a: shows schematically a further embodiment of a pillar-beam structure according to the invention,
Figure 4b: shows an example pillar attachment,
Figure 4c: shows a further example pillar attachment,
Figure 5a: shows a step of attaching a pillar,
Figure 5b: shows a completed pillar attachment.

Figure 1 shows schematically the structure and formation of a wooden pillar-beam structure according to the invention. The invention relates more specifically to a wooden pillar-beam structure equipped with glass elements and a method for manufacturing the same. Generally speaking, a pillar-beam structure comprises essentially vertical wooden pillars 10 belonging to a load-bearing structure 13 of a building and glass elements 11. A glass element 11 is supported to a wooden pillar 10 in the pillar-beam structure. Wooden pillars can be used in timber and log buildings as well as in other buildings and structures. Figure 1 shows six wooden pillars 10 supported in a vertical position, which here form part of a load-bearing structure 13 supporting a roof 12. In other words, the wooden pillars bear vertical loads. The wooden pillars are preferably glulam pillars, although solid wood pillars can also be used. The wooden pillars can be supported by means of crossbeams 14, whereby a lattice structure is formed. Despite notches in the logs and various fasteners, the intersecting points in a wooden lattice structure are active joints. While the wooden pillars are able to withstand vertical loads, the lattice structure moves laterally due to the action of, for example, a wind load. A lateral load i.e. horizontal load in the direction of the wall is shown by the arrow F in Figures 1 and 4a. Attaching the glass elements is challenging due to deformations so that metal beams have been used in the past in order to provide the lattice structure with an adequate stiffness. Large glass surface areas are, however, part of contemporary building technology so that consumers want to have them. For instance, an entire face of a building can be glazed, as shown in Figures 1 and 4a. Loads nevertheless demand metal structures in the known art, which can become considerable compared to wooden structures. Moreover, joining metal and wood together requires special solutions that increase costs as well as the amount of time necessary for the erection of the building.
Figure 2 shows a completed pillar-beam structure according to the invention in cross-section at the site of a wooden pillar 10. In the invention, the glass element is arranged as a stiffener by means of which the lattice structure formed from the wooden pillars and the crossbeams is rendered stiff without metal beams. More specifically, the glass element 11 is attached by adhesive bonding in order to stiffen the pillar-beam structure. This way, the adhesive receives, together with the glass element, the shear forces caused by a lateral load. In the structure according to the invention, stiffness is provided to the lattice structure by means of the adhesively bonded glass elements. The glass sheet adhesively bonded to the wooden pillars and possible crossbeams turns the structure into a plated structure that is stiff in the lateral direction.
In the embodiment of Figure 2, a metal strip 15 mechanically attached to the wooden pillar 10 is also used. A corresponding metal strip is also used, if necessary, for the crossbeams 14.
The adhesive bond between the glass and the metal is ensured by means of the metal strip. The attachment between the metal and the wood is similarly ensured by means of the mechanical fixation.
One advantageous adhesive is a reactive urethane adhesive, which works with both metal and glass. The open time of urethane adhesives can be adjusted. When it is hot-applied, the adhesive forms an initial bond while cooling before it reacts with moisture to reach its final strength. Urethane adhesives are highly resistant to temperature fluctuations and vibrations and do not release harmful organic compounds. The adhesive bond 16 is preferably a polyurethane adhesive. Another example of a suitable adhesive is a cold-applied polyurethane with the brand name SikaTack^®.
After installation, the space between the glass elements is filled, for example with an elastic mass 17. The elastic mass finishes the structure and prevents water and contaminants from entering between the glass elements. The edges of the glass element can have tinted or darkened areas 18 that cover the adhesive seams. In other words, the adhesive seams remain concealed when viewed from the outside. The darkened area additionally protects the adhesive layers from ultraviolet radiation. For example, the darkened area can be formed by screen printing or digital printing. The printed surface can also cover all or at least most of the area of the glass element. The transparency of the glass element can thus be customized at desired locations. At the same time, at least a part of the wooden pillars and crossbeams remains concealed, which enhances the sensation of a solid glass wall when viewed from the outside.
The glass element 11 is consequently attached by means of an adhesive connection 16 in the invention. The glass element thereby acts as a stiffener, which impedes a lateral movement of the lattice structure. In the shown embodiments, a counterpart 19 is attached the wooden pillar 10 and the adhesive connection 16 is provided between the counterpart 19 and the glass element 11. The counterpart can be the aforementioned metal strip which is mechanically attached to the wooden pillar. This makes is possible to ensure the integrity of the adhesive connection when the surfaces are flat and the behaviour of the adhesive with different materials is known. In addition, a mechanical connection is provided between the wooden pillar 10 and the counterpart 19. The counterpart 19 is attached simply with wood screws 20. In the embodiment of Figure 2, the counterpart is a metal strip 15, which is preferably made of aluminium. Aluminium is a light and rustproof material that can be easily worked at a construction site. It is also possible to produce complex shapes where necessary by means of extrusion, although in most cases a flat strip of metal, preferably already perforated, is sufficient. This makes attachment easy and a sufficient number of screws should be available, as the perforations indicate the location and number of fasteners.
The metal strip can be readily attached to a smooth surface of a wooden pillar. The counterpart 19 can comprise designs for which the wooden pillar 10 comprises a matching groove 21 (Figure 3). Not only does the matching groove facilitate the attachment of the counterpart, the counterpart will also be in the right place thanks to the matching groove. The matching groove also accommodates a receiving point 22 belonging to the counterpart 19 for the installation support 23. The receiving point can be a nut attached to the counterpart or an internal Helicoil thread. While the glass elements are being attached by means of adhesive bonding, the installation supports 23 are temporarily attached by means of bolts 24, which are attached to nuts 25 in the counterpart 19. Once the adhesive connection has dried, the bolts and installation supports are removed and the gaps between the glass elements are filled with an elastic mass as shown in Figure 2.
In addition to the wooden pillars 10, the wooden pillar structure also includes horizontal crossbeams 14 to which the glass elements 11 are attached by means of an adhesive connection 16, analogously to the wooden pillars. Active joints are thereby eliminated from the lattice structure so that the final product is a stiff structure in which the glass elements act as stiffeners.
In the shown embodiments, a thermal glass element constituted by two or three glass sheets is used. More specifically, the glass element 11 comprises a plurality of glass sheets 26, 27 and 28 arranged in relation to one another, of which the glass sheet 26 to be employed in the adhesive connection is thicker than the others. The thickness of the glass sheet is thus determined by the dimensions of the structure, i.e. by the required stiffness and load-bearing capacity. The other glass sheets can then be selected based on the required insulation. In the invention, the thicker glass sheet is 6 - 12 mm thick and the glass is tempered. Two thinner glass sheets can also be laminated into one thick glass sheet, the resulting glass element being then glued to the pillar-beam structure. On the other hand, a solid glass sheet of a sufficient thickness can also constitute a glass element, which is attached by means of adhesive bonding in accordance with the invention.
In the method according to the invention, glass elements 11 are supported to substantially vertical wooden pillars 10. In the invention, the glass elements 11 are supported to attachment by means of adhesive bonding. Adhesive bonding is a quick and easy way to attach glass elements. What is significant about the wooden pillars and glass elements, however, is the resulting stiff lattice structure, the lateral movement of which is negligible. The use of metal beams is simultaneously avoided, since the glass elements act as stiffeners. Moreover, the carbon footprint of a wooden structure over its life cycle is significantly lower than that of a metal lattice. A comparison of the climate impact of buildings in different countries has shown, for instance, that the carbon footprint of wooden buildings is well under half that of concrete buildings.
During bonding, more precisely during the hardening of the adhesive, the glass elements 11 are attached mechanically to the pillar-beam structure. Preferably, the described receiving points provided in the counterpart are used. This is shows in Figure 3. Once the adhesive has dried, the bolts 24 and the installation supports 23 are removed and the gaps between the glass elements are filled with an elastic mass 17.
A part of the pillar-beam structure can be prefabricated and subsequently attached to form part of the building 29. In this case, the part in question can be manufactured horizontally on a flat surface so that the dimensions and geometry of the final product are rendered precise. A running of the adhesive is simultaneously avoided and the adhesive dries indoors even in winter. Such a part is then transported to the construction site and joined to the building. Depending on the situation, the stiffened part is sufficient to stiffen the entire pillar-beam structure so that the remaining glass elements can be attached by a means other than bonding. The prefabricated part can be, for example, the size of the area designated by the dashed line in Figure 1. The part in question can still be transported together with other construction materials without special transport. Even if part of the structure is prefabricated, the rest of the glass elements can be attached by means of adhesive bonding at a construction site. Most of the glass elements, often all the glass elements, are supported in one way or another to a wooden pillar.
Figure 4a shows a variant of the pillar-beam structure according to the invention. In this case, more than half of the openings of the lattice structure are covered with glass elements 11. The glass elements are practically joined to one another so that the facade appears to be a solid sheet of glass. The wooden pillars may be dimly visible through the glass elements (dashed lines). The structure otherwise corresponds to the embodiment of Figure 1, with the difference that one or more wooden pillars 10 are attached by means of a rotationally stiff attachment 30, which contributes to the bearing of lateral loads and thus significantly stiffens the lattice structure. In other words, a rotationally stiff attachment 30 is provided between one or more wooden pillars 10 and the foundation 31 of the building 29. The rotationally stiff wooden beam forms a support column, whereby metal beams are altogether avoided.
Figures 4b and 4c show two examples of an attachment of a wooden support column to a foundation 31 of a building 29, such as a cast or slab floor. The examples are essentially identical, as only the dimensioning is different. Figure 4b shows a 140*270 mm wooden pillar 10 in a plan view. In Figure 4c, the size of the wooden pillar 10 is 270*270 mm. The dimensions of the wooden pillars are thus identical as far as the attachment of the glass elements is concerned, merely the dimension of the wooden pillar towards the interior of the building increasing somewhat. The stiffness of the lattice structure can thereby be easily increased without modifying other dimensions. A steel base plate 32 is implemented here, wherein studs 33 welded to the latter are adhesively bonded to the bottom of the wooden pillar 10. Adhesive bonding can occur at a factory or at a construction site. Polyurethane adhesives are preferably used here as well. The foundation 31 accordingly has anchors arranged in a cast floor or threaded rods 34 soldered to bores. Anchors are cast in a concrete slab at a factory while threaded rods are soldered at the construction site. In practice, a sufficient number of holes are bored into the concrete slab at the site of installation of the support column and the threaded rods are soldered to these holes. The support column is then installed in an upright position so that the holes in the base plate are aligned with the threaded rods. Finally, nuts 35 are installed and tightened on the threaded rods, whereby the wooden pillar is attached at its bottom end with a moment connection so as to form a functional support column. It is alternatively possible to use a pillar shoe that can be attached to the foundation, to which the wooden pillar is attached by means of long longitudinal screws (not shown).
Figures 5a and 5b show an installation and attachment of a wooden pillar 10 with a moment connection. Threaded rods 34 are already soldered to the foundation 31 in this example. The base plate 32 has accordingly already been bonded to the wooden pillar at the factory. In Figure 5a, the wooden pillar 10 is lowered towards the threaded rods 34. In Figure 5b, the wooden pillar 10 is already attached in position with a moment connection.
By means of the stiffening provided by the glass elements, it is possible to replace diagonal stiffeners that would otherwise traverse one or more openings of the lattice structure. The openings thus remain open so that the window area can be maximized while providing an unobstructed view. The stiffness of the lattice structure can be ensured by attaching one or more wooden pillars to the foundation by means of a moment connection. Alternatively, or additionally, it is possible to use one or more wooden pillars that do not belong to the lattice structure, which are attached to the foundation by means of a moment connection and which buttress the lattice structure. The lattice structure can thus be rendered slender or else be dimensioned so as to be lighter, as shear forces are borne by one or more support columns. In principle, the stiffness of the lattice structure is achieved by means of the bonded glass elements while the wooden pillars bear vertical loads. Other supports are used for particular reasons. For example, a support column also bears transverse loads of a wall.
The pillar-beam structure according to the invention is ideally suited for timber construction as well as in part for buildings made of other materials. A single glass element can be up to ten square metres in size. The main limiting factor is the mass of the glass element. A triple-glazed thermal glass element can weigh almost a hundred kilograms per square metre so that auxiliary tools are required for handling and installation. Once the adhesive has reached its final hardness, separate fasteners are not necessary. The final product is thus neat and tidy and devoid of protrusions or masking strips. The cross-sectional surface area of the wooden pillar can simultaneously be reduced, as movement is eliminated and in particular buckling is prevented. This permits the formation of slender structures with large openings.

Claims

Wooden pillar-beam structure equipped with glass elements, which comprises essentially vertical wooden pillars (10) belonging a load-bearing structure (13) of a building (29) as well as glass elements (11), wherein a glass element (11) is supported to a wooden pillar (10) in the beam-pillar structure, characterized in that the glass element (11) is attached by means of an adhesive connection (16) in order to stiffen the pillar-beam structure.
Pillar-beam structure according to claim 1, characterized in that the adhesive connection (16) is provided between the glass element (11) and the wooden pillar (10).
Pillar-beam structure according to claim 1, characterized in that a counterpart (19) is attached to the wooden pillar (10) and the adhesive connection (16) is provided between the counterpart (19) and the glass element (11).
Pillar-beam structure according to claim 3, characterized in that a mechanical connection is provided between the wooden pillar (10) and the counterpart (19).
Pillar-beam structure according to claim 3 or 4, characterized in that the counterpart is a metal strip (15), which is preferably made of aluminium.
Pillar-beam structure according to any of claims 3 - 5, characterized in that the wooden beam (10) comprises a matching groove (21) for the counterpart (19).
Pillar-beam structure according to any of claims 3 - 6, characterized in that the counterpart (19) comprises a receiving point (22) for an installation support (23).
Pillar-beam structure according to any of claims 1 - 7, characterized in that a rotationally stiff attachment (30) is provided between one or more wooden pillars (10) and a foundation (31) of the building (29).
Pillar-beam structure according to any of claims 1 - 8, characterized in that, in addition to the wooden pillars (10), the pillar-beam structure further comprises horizontal crossbeams (14) to which the glass elements (11) are attached by means of an adhesive connection (16).
Pillar-beam structure according to claim 9, characterized in that a counterpart (19) is attached to the crossbeam (14) and an adhesive connection (16) is provided between the counterpart (19) and the glass element (11) while a mechanical connection is provided between the crossbeam (14) and the counterpart (19).
Pillar-beam structure according to any of claims 1 - 10, characterized in that the glass element (11) comprises a plurality of glass sheets (26, 27, 28) arranged in relation to one another, of which the glass sheet (26) to be employed in the adhesive connection (16) is thicker than the others.
Method for forming a wooden beam-pillar structure equipped with glass elements, in which method glass elements (11) are supported to essentially vertical wooden pillars (10) belonging to a load-bearing structure (13) of a building (29), characterized in that the glass elements (11) are supported to an attachment by means of adhesive bonding in order to stiffen the beam-pillar structure.
Method according to claim 12, characterized in that the glass elements (11) are mechanically attached to the pillar-beam structure during bonding.
Method according to claim 12 or 13, characterized in that a part of the pillar-beam structure is prefabricated and is attached to form part of the building (29).
Method according to claim 13, characterized in that the glass elements (11) are pre-attached to the prefabricated pillar-beam structure.