LOAD BEARING BEAM MADE OF WOOD FOR BUILDING STRUCTURES OF

VARIOUS KIND AND BUILDING STRUCTURES REALIZED BY MEANS OF A PLURALITY OF SUCH LOAD BEARING BEAMS MADE OF WOOD

The invention relates to a load bearing beam made of wood for building structures of various kind, with new and original constructive characteristics increasing the structural strength and the anti-fire resistance thereof, and also relates to building structures realized by means of a plurality of such load bearing beams made of wood. There are known building structures of various kind composed of laminar wood, of reticular type, and normally realized with beams made of wood such as laminated beams, "parallam" beams, massive beams, "bilam", "trilam" beams and the like, which are secured into position by means of connectors made of steel and/or carbon and are reinforced with steel plates in the articulated joints thereof. These building structures have an average level of anti-fire resistance normally not higher than R 30, with an average level of 0,13 cubic meters for m2 of structure, and therefore these reticular structures are much flexible in their applicative capacity, however have high limits in their anti-fire resistance which cannot exceed the limit of R 60, otherwise there are needed structures having larger cross-section sizes, and the use of anti-swelling paints applied thereon is required, with consequent higher cost burdens for making this kind of constructive structures.

There are also known building structures of various kind composed of boomerang and/or curved shaped beams made of laminar wood, allowing to reach larger limits of anti-fire resistance with respect to the reticular structures, however under the same mechanical strength they need the use of larger quantities of wood, with a unit cost for cubic meter of

wood which is considerably higher with respect to that of the reticular structures, and therefore with higher construction costs.

Finally, there are known building structures of various kind composed of laminar wood beams, of reticular type, in the articulated joints of which there are applied some reinforcing plates made of laminar wood, allowing to reduce in a considerable way the quantity of wood used with respect to that of the reticular structures, under the same mechanical strength which is obtained, however owing to the stratified beam composition the anti-fire resistance of these structures is widely reduced, in that the limit of such anti- fire resistance is lower than that of the reticular structures and cannot exceed the R 30 value.

The object of the present invention is to overcome the above described drawbacks and limits deriving from the use of building structures known from the art, by means of the use of building structures of various kind composed of a plurality of load bearing beams made of wood which are realized with the new and original constructive characteristics substantially described, with particular reference to the enclosed patent claims.

The invention will be better understood from the following description, given by way of not limitative example only and with reference to the accompanying drawings, in which :

- Fig. 1 shows a front view of a load bearing beam made of wood according to the invention, with its various component parts assembled to each other ; - Fig. 1 a shows a front view of an enlarged constructive item of the beam of Fig. 1 ;

- Fig. 2 shows a front view of the load bearing beam of Fig. 1 , with its various component parts disassembled from each other ;

- Fig. 3 shows a side view of the beam of Fig. 1 built in for making a building structure ;

- Fig. 4 shows a side perspective view of a terminal portion of the beam of Fig. 1, with its various component parts assembled to each other ;

- Fig. 4 a shows, with the same view of Fig. 4, an enlarged constructive item of the beam of Fig. 1 ;

- Fig. 5 shows a side exploded perspective view of the terminal portion of the beam of Fig. 4, with its various component parts disassembled from each other ; - Fig. 6 shows a side perspective view of a terminal portion of the beam of Fig. 1, covered with side coverings, with its various component parts assembled to each other, in a constructive version thereof ;

- Fig. 6 a shows, with the same view of Fig. 6, an enlarged constructive item of Fig. 6 ;

- Fig. 7 shows a side exploded perspective view if the terminal portion of the beam of Fig. 6, with its various component parts disassembled from each other ;

- Fig. 8 shows a side perspective view of the terminal portion of the beam of Fig. 1, in a further constructive version thereof ;

- Fig. 8 a show, with the same view of Fig. 8, an enlarged constructive item of Fig. 8 ;

- Fig. 9 shows a side exploded perspective view of the terminal portion of the beam of Fig. 8, with its various component parts disassembled from each other ;

- Fig. 10 shows a front view of the beam of Fig. 1, in a constructive version thereof ;

- Fig. 11 shows a front view of some assembled beams of Fig. 1, on a step of reciprocal coupling thereof and covered with side coverings ;

- Fig. 12 shows a front view of a larger number of assembled beams of Fig. 1, on a step of reciprocal coupling with relative coupling elements thereof, and covered with side coverings ;

- Fig. 13 shows a front view of the beam of Fig. 1, in a different coupling version thereof with additional component parts ;

- Fig. 13 a shows, with the same view of Fig. 13, an enlarged constructive item of Fig. 13 ; - Fig. 14 shows, with the same view of Fig. 13, the beam of Fig. 13 with its various

component parts disassembled from each other ;

- Fig. 15 shows a side view of the beam of Fig. 13 built in for making a building structure ;

- Fig. 16 shows a front view of the beam of Figs. 8 and 9, covered with side coverings ;

- Fig. 16 a shows, with the same view of Fig. 16, an enlarged constructive item of Fig. 16 ; - Fig. 17 shows, with the same view of Fig. 16, the beam of Fig. 16 with its various component parts disassembled from each other ;

- Fig. 18 shows a side view of the beam of Fig. 16 built in for making a building structure ;

- Fig. 19 shows a front view of the beam of Fig. 1, in a further constructive version thereof;

- Fig. 19 a shows, with the same view of Fig. 19, an enlarged constructive item of the beam of Fig. 19 ;

- Figs. 20 and 21 show a respective side perspective view and front view of the terminal portion of the beam of Fig. 19, with its various component parts disassembled from each other ;

- Fig. 22 shows a side view of the beam of Fig. 19 built in for making a building structure ; - Fig. 23 shows a side perspective view of the terminal portion of the beam of Fig. 19, with its various component parts assembled to each other, and in a constructive version thereof ;

- Fig. 24 shows a side perspective view of a beam coupled with various component parts, in another constructive version thereof, the component parts of which are reciprocally assembled ; - Fig. 25 shows a side exploded perspective view of the beam of Fig. 24, with its various component parts disassembled from each other ;

- Fig. 26 shows a perspective front view of a building structure which can be obtained with a plurality of beams of the type shown in the Figs. 8 and 9 ;

- Fig. 27 shows a perspective front view of a building structure which can be obtained with a plurality of beams of the type shown in the Figs. 24 and 25 ;

- Fig. 28 shows seven examples of building structures which can be obtained with the load bearing beams made of wood according to the invention ;

- Fig. 29 shows a front view of a load bearing beam made of wood according to the invention, formed by various portions of beams identical and joined to each other ; - Fig. 30 shows a side view of the joint of two portions of beams of the Fig. 29 ;

- Fig. 31 shows a plan view of the beam of Fig. 29 ;

- Fig. 31 a shows, with the same view of Fig. 31, an enlarged constructive item of the beam of Fig. 31 ;

- Fig. 32 shows a plan view of the beam of Fig. 29, with its various component parts disassembled from each other ;

- Fig. 33 shows a side perspective view of the beam of Fig. 29, with two portion thereof joined to each other by a joint ;

- Fig. 34 shows a side exploded perspective view of the two portions of the beam of Fig. 29, disassembled from each other and on the joining step thereof ; - Fig. 35 shows a front view of more load bearing beams made of wood coupled to each other, formed by various portions of beams identical and joined to each other ;

- Fig. 36 shows a side view of the joint of two portions of the one of the beams of Fig. 35 ;

- Fig. 37 shows a plan view of the coupled beams of Fig. 35 ;

- Fig. 37 a shows, with the same view of Fig. 37, an enlarged constructive item of the coupled beams of Fig. 35 ;

- Fig. 38 shows a plan view of the coupled beams of Fig. 35, with their various component parts disassembled from each other ;

- Fig. 39 shows a side perspective view of the beams coupled to each other of Fig. 35, with two portions thereof which are joined to each other by another type of joint ; - Fig. 40 shows a side exploded perspective view of the two portions of the one of the

beams of Fig. 39, disassembled from each other and on the joining step thereof ;

- Fig. 41 shows a side perspective view of the coupled beams of Fig. 35, with two portions thereof joined to each other with the same type of joint ;

- Fig. 42 shows a front view of more beams coupled to each other with another type of joint, applied in a determinate position ;

- Fig. 43 shows a side perspective view of Fig. 42, for pointing out the beam joint ;

- Fig. 44 shows a side exploded perspective view of the beams of Fig. 42, with their various component parts disassembled from each other and on the joining step thereof ;

- Fig. 45 shows a front view of more beams coupled to each other with the same type of joint of Fig. 42, applied in other positions ;

- Fig. 46 shows a side perspective view of Fig. 45, for pointing out the positioning of the joint ;

- Fig. 47 shows a side exploded perspective view of the beams of Fig. 45, with their various component parts disassembled from each other and on the joining step thereof ; - Fig. 48 shows a side perspective view of an angle connection of two beams having the shape shown in Fig. 8.

The above Figures represent a plurality of load bearing beams made of wood according to the present invention, which are employed for making building structures of various kind having the characteristics of greater mechanical strength and anti-fire resistance with respect to beams made of wood known from the art, some structures of which will be illustrated by way of not limiting example only.

Figs. 1-2 illustrate a load bearing beam 10 made of wood according to the invention, while Fig. 3 illustrates a load bearing beam 10 built in for making a building structure of any type, together with further identical load bearing beams (not visible), which are adequately combined and joined to each other. As visible particularly from Figs. 1 and 2, this load

bearing beam made of wood 10 is formed substantially by at least a central vertical core 11 having an outline preferably of parallelepiped shape, which is extended for the entire length of the beam, and by at least an upper flange 12 and at least a lower flange 13, preferably of parallelepiped shape with horizontal extent, each one of which is associated to and coupled as it will be described with the relative end portion of the central core 1 1 and extends for the entire length of the same core, and therefore for the entire length of the beam. In particular, the central core 1 1 is substantially formed by a plurality of sheets of wood of any kind, of the same thickness and/or different thickness, preferably of thin thickness, but which may be also of wider thickness, and of the same shape and length of the central core 1 1, said sheets of wood being placed side by side and joined to each other by means of adhesives or other suitable fixing means, so as to form the so-called LVL (laminated veneer lumber) and relative multi-layered panels (plywood). In particular, such sheets of wood are covered on their opposite surfaces with the adhesives for being reciprocally coupled and are orientated mainly in two different manners : a) a first manner, in which the wood grains of each sheet are orientated in the same direction of the grains of the respectively adjacent sheets and also of those of the remaining sheets of wood, and in particular they are all orientated either in the direction of the length of the central core, and therefore of the beam, or in the direction of the height of the central core, and therefore of the beam ; b) a second manner, in which the wood grains of each sheet are orientated in a determinate direction (by length or height), and the grains of each sheet respectively adjacent to such sheet are orientated in a direction orthogonal to the grains of the same sheet (by height or length). In the case in which the beam is composed of different central cores 1 1 , these latter are put side by side and coupled to each other with adhesives, fixed joints or other fixing means of traditional type. The panels coupled to each other in the manner as

described, forming the central cores 1 1 may be constituted, by way of not limiting example only, by laminated plywood panels of the type "Kerto", preferably the type "Kerto-Q" with laminated layers arranged longitudinally and transversally to the longitudinal direction of the same panels, which are manufactured by the Firm Finnforest Merk GmbH, with seat at 86551 Aichach (Germany), Industriestrasse 2, however such panels may be also made by other industries with this structure.

In turn, each one of the upper flange 12 and lower flange 13 is formed by a plurality of laminated wood elements of any kind, having the same thickness and/or different thickness, and the same shape and size of each flange, said laminated wood elements being put side by side or overlapped and joined to each other in the longitudinal direction of the flange by means of adhesives or other suitable fixing means, so as to form wood laminas with longitudinal extent having the same length and/or variable lengths, and the same or variable heights. By way of example only, such laminas may be made with heights comprised between 33 and 46 mm. Each one of the upper flange 12 and lower flange 13 may be formed also by massive wood of any kind, having the same shape of the relative flange, which extends for the entire length and/or a length smaller than that of the same flange, so as to form a series of laminas with identical and/or different length, which are joined to each other in the longitudinal direction of the relative flange by means of fixed joints, adhesives or joints of various kind, up to the complete length of the same flange. As alternative, the laminated wood elements of each flange may be also constituted by a plurality of veneer stripes of variable thickness, coupled with adhesives in the direction parallel to the beam longitudinal axis, and offset to each other, of the type commonly known as "parallam" beams (PLS = parallel strand lumber). Finally, the flanges may be also constituted by multi-layered laminated plywood, for example of the already described type "Kerto". Fig. 2 shows the manner in which the two upper flanges 12 and the two

lower flanges 13 of each beam are obtained. From such Figure, it is noted that each flange is formed by at least two separated half-flanges, having the same shape and identical and/or different size, which are adequately secured the one to one side and the other one to the opposite side of the central core 1 1, in the relative application position to such central core. In this case, there are noted four half-flanges separated from the central core 1 1 , and formed respectively by the two upper half-flanges 12' and 12" which are arranged on and fixed to the upper end portion of the central core 1 1, the first one to the left side and the second one to the right side of the same core, and by the two lower half-flanges 13' and 13", which are arranged on and fixed to the lower end portion of said central core, the first one to the left side and the second one to the right side of the same core.

From Fig. 1 a there are noted in an enlarged scale the two lower half-flanges 13' and 13" fixed from the two sides to the central core 1 1 , at its lower end portion, so as to form the beam lower flange 13, which is so shaped like a double "T" beam, while from Fig. 3 it is noted a beam of this kind applied in a generic building structure, by forming for example the floor of the same structure. It is to point out that all the half-flanges are always fixed from the exterior to the core, and as a consequence thereof the mechanical stresses strength of the beam is increased, in that such stresses are distributed in the different contact and fixing points among the different component parts of the beam, and therefore among more component parts, and the anti-fire resistance of the so constituted beam is also increased, in that the beam structure is composite and not homogeneous so that, in the case of fire, the flame diffusion from the one to the other one of the component parts of the same beam is made more difficult and delayed. Vice versa, the coupling between the half-flanges and the central core isn't never effected by notching the half-flanges for inserting the core into such notches, in that in such case the mechanical stresses would be distributed over a smaller number of component parts, as it occurs at the present time, thereby reducing the

mechanical stresses strength of the beam as well as the anti-fire resistance thereof, in the case of fire, owing to the fact that in such case the flame would be spread more easily and quickly through the smaller number of component parts of the so realized beam. The beam obtained according to the present invention may be built in for forming building structures of various kind, particularly floors and ceilings, and may withstand to mechanical stresses of different intensity and have greater anti-fire resistance depending on the selected types of wood and the sizes of the core and the flanges of each used beam. Figs. 4 and 5 show a beam according to the invention, composed as described above by a single central core 1 1 only, and an upper flange 12 and a lower flange 13, formed by half- flanges as described, however each beam may be also composed of a plurality of central cores with relative upper and lower flanges, which are put side by side and joined to each other with fixing systems of various kind. Some examples of beams shaped with more cores and more flanges will be described later on, with particular reference to the Figures 11, 12 and 35-47. From Fig. 5 it is noted the end portion of a load bearing beam made of wood of the type referred to, with its various component parts disassembled from each other, which are marked with the same reference numerals previously used ; in this case, this end portion and the other beam end portion too are provided with a respective pair of short vertical reinforcing stanchions 14 and 15, identical to each other and dimensioned for being adapted between the opposite half-flanges 12', 12" and 13', 13" and also to the corresponding outer side of the beam central core 11 , and then to be joined to these component parts with traditional fixing systems.

From Figs. 6 and 7 it is noted the end portion of a portion of a load bearing beam 16 composed as indicated in the Fig. 5, the sides of which have been covered with corresponding side protecting covering panels 17 and 18, made of LVL laminated wood, or wood of the multilayered type, or the like, which are at first arranged, against the relative

half-flanges and thereafter secured thereto with traditional fixing systems. In particular, from Fig. 6 it is noted the beam with all its component parts assembled to each other, while from Fig. 7 it is noted the beam with all its component parts disassembled from each other and on the assembling step thereof. Moreover, from Fig. 6 it is noted that the beam portion covered with the side panels 17 and 18 is coupled in the longitudinal direction with an identical adjacent beam portion 19 by means of a metallic joint 20, or other suitable joining system, in a manner that the complete beam is composed of different beam portions, having the same length and/or lengths different from each other, and that each beam portion is covered by covering panels applied and fixed to the reinforcing stanchions 14 and 15, which in the example of Fig. 7 are arranged not only at the end portions but also in the intermediate longitudinal positions of the complete beam.

Figs. 8 and 9 show a further possible constructive version of the beam according to the present invention, with its component parts respectively assembled and disassembled from each other, wherein the beam is made identical to that of Fig. 7, namely it is provided with a plurality of reinforcing stanchions 14 and 15 spaced away from each other in the beam longitudinal direction, however with respect to the previous case here the beam isn't covered with covering panels. Fig. 10 illustrates a beam central core 11 in a constructive version, in which it is coupled with short vertical reinforcing beams (not shown), shorter than the core height, and arranged against the one or both the sides of the same core, which beams are fixed to each other and to the core by means of fixing systems of traditional type, and preferably by pre-stretched cables 21 adequately secured to the end portions of the core cross section, in a manner to ensure the factional coupling between the adjacent surfaces of the various component parts thereof. Figs. 1 1 and 12 show the central cores of different beams, arranged parallel to each other and in the step of reciprocal coupling thereof, which are covered at their outer sides by side

coverings. In particular, from Fig. 1 1 there are noted three central cores 1 1 , 1 1 ' and 1 1 " coupled parallel to each other, and the two side coverings 17 and 18 which are coupled to the side cores 1 1 ' and 1 1 " by means or adhesives or other fixing systems of traditional type, while from Fig. 12 there are noted five central cores 1 1, 1 1 ', 1 1 ", 1 1 '" and 1 liv coupled parallel to each other and to the relative intermediate reinforcing beams 22, and the two side coverings 17 and 18 coupled to the side cores 1 1 ' and 1 1 iv by means of lengthened jacks 23 which are inserted through the side coverings and all the beam cores. Figs. 13 and 14 show a different coupling version of the various component parts of the beam, in which there are still provided vertical reinforcing stanchions 14 and 15, like those of Figs. 8 and 9, and there are also provided inclined reinforcing beams having symmetrical inclinations between the one and the other one of the vertical stanchions, thereby forming a trestle structure. Fig. 15 illustrates by way of example a building structure formed by beams of this kind, for example for forming a floor, in which it is noted the trestle structure formed by the vertical stanchions 15 secured laterally to the beam in positions spaced away longitudinally from each other, which are joined to each other respectively with an inclined beam 24 having a determinate inclination and with another inclined beam 25 having a symmetrical inclination. Figs. 16 and 17 show a beam of the same type illustrated by Figs. 8 and 9, which is covered by side coverings 26 and 27 of the same material, the outer surface of which is decorated with figures, symbols and drawings etc.. of various kind, made for example by means of milling or similar machinings, so as to confer different aesthetical and decorative appearances and on the customer request.

Fig. 18 illustrates by way of example a building structure formed by so covered beams, for example for constituting a floor, in which under the outer covering 27 there are noted the various vertical reinforcing stanchions 15 of the beam.

Figs. 19-21 show an additional constructive version of the beam, of the same type illustrated by Figs. 8 and 9, and with side coverings 28 and 29, and in this constructive version a relative hollow space is formed between the side coverings 28 and 29 and the central core 1 1, into which hollow space at least a corresponding insulation 30 made of suitable material is inserted, in order to protect, in the case of fire, the central core and the upper and lower flanges of the beam from the fire action, thereby increasing the anti-fire resistance of the entire beam structure.

Fig. 19 shows this type of beam with its various component parts assembled to each other, while Figs. 20 and 21 show this beam with its various component parts disassembled from each other and in the assembling step thereof. Fig. 22 illustrates by way of example a building structure formed by so covered beams, for example for constituting a floor, in which under the outer covering there are noted the various vertical reinforcing stanchions 15 of the beam. Fig. 23 shows a constructive version of the beam of the type illustrated by Figs. 19-21, which however is not provided with side covering. Figs. 24 and 25 show another constructive version of a beam, not provided with side coverings and insulation and still provided with vertical reinforcing stanchions 15 like those of Figs. 8 and 9, and a trestle structure formed by inclined reinforcing beams 24 and 25 having inclinations symmetrical to each other, secured into intermediate positions to the different stanchions 15, as in the case of Figs. 13 and 14, however in this case the inclined beams may perform the function of stiffening and reinforcement, like a conventional reticular beam, or also the sole aesthetical function. Furthermore, instead of being made firstly separately and then secured to the stanchions and the beam central core, the inclined beams may be made directly into the position, by arranging some side panels among the different reinforcing stanchions and mechanically shaping such panels with the desired aesthetical outlines, so as to form also the beams directly during this working.

Figs. 26 and 27 show two examples of building structures of any kind which are realized by employing some beams of the above described types, and in particular in the Fig. 26 by employing some beams of the types illustrated in the Figs. 8 and 9, and in the Fig. 27 by employing some beams of the types illustrated in the Figs. 13 and 14. Fig. 28 illustrates seven examples of building structures having different shapes by employing some beams according to the invention, for example for forming ceilings and walls. Of course, the building structures attainable with the described beams may have the more different structures, mainly but not exclusively for forming floors and ceilings, by employing some beams of the same kind and/or of kind different to each other, having shapes and dimensions fit to withstand mechanical stresses and have anti-fire resistances required from time to time, thus without departing from the protection sphere of the present invention. Figs. 29-32 illustrate a beam composed of different beam portions joined to each other, which are packed into packages with limited sizes and transported in the installation sites, where they are reciprocally connected by means of junctions of various kind, so as to form the complete beam. In the example referred to, there are visible two beam portions 31 and 32, which are connected to each other with their heads by means of at least a relative joint 33 made of sheets of laminated veneer lumber (LVL), which joint is fixed with adhesives or the like to the central core 1 1 and with panels or steel plates 34 to the relative upper and lower flanges of the relative beam portion. In such case, as better visible from Figs. 32-34, the upper half-flanges 12', 12" and the lower half-flanges 13', 13" of each beam portion are cut with different lengths, in a manner that the junction zone thereof isn't situated in correspondence of the joint 33, then such joint is at first arranged on and fixed to the relative side of the central core 1 1, and then on the upper and lower edges of the same joint there are applied the corresponding half-flanges, which are then joined to each other with their heads by means of the panels or

plates 34, the end portions of which are inserted and fixed through relative side grooves 35 and 36 of two half- flanges respectively adjacent to each other.

Figs. 35-41 show more load bearing beams made of wood, in the example constituted by three beams, which are arranged parallel and coupled to each other by means of adhesives or other traditional fixing systems, wherein each beam is formed by various beam portions which are joined to each other with the same means and the same criteria described in the Figs. 29-34, which therefore are marked with the same reference numerals thereof, wherein in the Figs. 35-38 the joints 33 are identical to the preceding ones, while in the Figs. 39-41 the various joints 33 are of different type, in that they are perforated to allow the insertion of thin fixing elements of various kind (not indicated) between the holes of the coinciding joints of the different beams. Figs. 42-44 show different beams arranged parallel and coupled by friction to each other, as visible in the Fig. 12, even with intermediate reinforcing beams 37, thanks to the employ of pre-stretched cables 38 which ensure the transversal prestress and are fixed to the sides of the structure and co-operate with external elements 41 , 42 made of wood, steel, aluminium and similar materials, allowing the uniform distribution of the produced prestress stretches.

Figs. 45-47 show several beams arranged parallel and coupled by friction to each other, without intermediate beams like those of Figs. 42-44, and with the same pre-stretched cables 38 described above, which in this case are used with numbers greater than the preceding ones, and are fixed in different positions to the structure, for performing always the same functions previously described.

Finally, Fig. 48 shows an angle connection of two beams of the type illustrated in the Figs. 8 and 9, in which it is noted that the end portions of the two beams are approached and joined to each other, in this case in the orthogonal direction thereof, by means of adhesives, and/or fixing devices of traditional type and the like. The beams according to the invention

allow to make building structure made of wood with large spans, with a reduced use of wood per square meter, and anti-fire resistance levels R 120. Besides, these beams allow to make structures of wood with costs almost similar to those of the structures of reinforced concrete.