Structural support beams
The invention relates to structural support beams for use in building and construction, which possess structural characteristics suitable for use as load-bearing flexural members. The support beam comprises a timber support frame formed from two spaced apart flanges connected by at least two outer support webs. Optionally one or more further inner support webs connect the flanges in an intermediate position between the outer support webs. Together, the flanges and support webs define at least one volume which is filled with a plastics foam material to provide both improved structural and sound/thermal insulation properties. The use of regular rectangular flanges, which are fully interposed between outer support webs, provides a stronger and stiffer support beam both in bending and in shear. In fact, the absence of grooves, recesses or cutout portions in the flanges provides further advantages such as greater dimensional stability, ease of construction and cheaper and simpler manufacturing. The support beams may be in the form of I-beams, double I-beams, box-beams, boxed I-beams or boxed double I-beams.
This invention relates to a structural support beam manufactured from a composite of materials, and in particular, but not exclusively, to a composite of timber in various forms with an infill of material that provides both added structural support and thermal/sound insulation, for use in the building and construction industry.
Support beams of the form of Laminate Veneer Lumber (LVL), Parallam products, Glulam products, I-joists and Box Beams, are known. These different support beams offer different structural properties and are used in different designs for different applications. For example, Parallam products have a high stiffness and strength compared to the other above-mentioned beams, but are heavier, more abrasive to saw and drill, require connection be made to adjacent beams with metal plates and bolts or dowels rather than nails, and are relatively costly; LVL products provide strength and consistent performance, are easy to work with, can be cut and nailed on site, resist shrinkage, warping, splitting and checking, but are relatively costly.
Box beams are also known as shown in
Box beams are moderately lightweight, can be handled easily, allow a higher load capacity than comparable sized timber, resist shrinkage, warping and checking and are more efficient than solid timber for large spans and loads.
However, such box beams are susceptible to shear buckling and therefore require web stiffeners to be positioned at points of increased load to counter localised web buckling. Furthermore, holes in the web can only be located where shear loads are low.
According to a first aspect of the present invention there is provided a structural support beam for use in building and construction comprising a support frame defining at least one volume, said support frame being of a first material and said at least one volume being in-filled with a second material.
Preferably, the support frame comprises two spaced apart flanges connected by at least two outer support webs.
Preferably, each outer support web connects lateral portions of the flanges.
Optionally, one or more additional outer support web(s) is/are positioned over one or both of the existing outer support webs.
Preferably, one or more inner support webs connect the flanges in an intermediate position between the outer support webs.
Optionally, one or more formations are provided in each flange to accommodate the outer support webs. Optionally, one or more formations are provided in each flange to accommodate the inner support web or webs.
Preferably, the formations are one or more of grooves, recesses and cut-out portions.
Preferably, the flanges are rectangular in shape.
Preferably, each flange is fully interposed between the outer support webs.
Optionally, each flange is provided with a reduced width portion to define a T-shaped flange.
Preferably, each reduced width portion is fully interposed between the outer support webs.
Preferably, the lateral edges of the other portions are adapted to be flush with the outer surfaces of the outer support webs.
Alternatively, the lateral edges of the other portions are adapted to extend beyond the outer surfaces of the outer support webs.
Optionally, a further end-flange is connected to the outer end of each existing flange.
Preferably, the lateral edges of each end-flange are adapted to be flush with the outer surfaces of the outer support webs.
Alternatively, the lateral edges of each end-flange are adapted to extend beyond the outer surfaces of the outer support webs.
Optionally, metal end plates are connected to the outer end of each flange.
Optionally or additionally, the metal end plates are connected to the outer end of each end-flange.
Preferably, the second material is less dense than the first material.
Preferably, the second material is a plastics foam material.
Preferably, the second material is adapted to give the support beam improved thermal and/or sound insulating properties.
Alternatively or additionally, the second material is adapted to give the support beam improved structural properties.
Preferably, the support frame is made from timber materials.
According to a second aspect of the present invention there is provided a structural support beam for use in building and construction comprising a timber based support frame formed from two spaced apart rectangular flanges connected by at least two outer support webs wherein the timber based support frame defines at least one volume in-filled with a plastics foam material; and wherein the plastics foam material is bonded to the flanges and webs.
Preferably, the outer support webs extend over the full depth of the flanges.
Preferably, the flanges are formed from solid or laminated timber material and the webs are formed from timber sheet material.
According to a third aspect of the present invention there is provided a method of manufacturing the structural support beam of the first aspect, said method comprising the steps of:
-
- (i) connecting two spaced apart flanges by means of at least two outer support webs to form a support frame defining at least one volume; and
- (ii) filling said at least one volume with an in-fill of material.
Preferably, the method comprises the additional step of bonding said in-fill of material to the support frame.
Preferably, the method comprises the further additional step of gluing and/or mechanically fixing the outer support webs to the flanges.
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
Referring to the drawings,
In a first embodiment of the present invention, as shown in
The outer support webs 112, 114 are glued and or mechanically connected to the flanges 116, 118. Typically, the flanges are of solid sawn timber, Glulam or LVL, and the webs are of a timber sheet product such as plywood or Oriented Strand Board (OSB).
The box beam 100 further includes an infill of support/insulating material 110 within a volume defined by the outer support webs 112, 114 and flanges 116, 118. The material 110 is less dense than the timber material from which the flanges and outer support webs are formed.
The material 110 is a plastics foam, for example, expanded polystyrene (EPS), extruded polystyrene, urethane, or other similar insulation cores that are bonded to the outer support webs 112, 114 and flanges 116, 118 to form a close contact. The material 110 may be of any type to improve both the insulation (thermal and/or sound) and/or structural properties of the box beam 100. The material 110 may be bonded to the interior surfaces of the outer support webs 112, 114 and the flanges 116, 118.
In a second embodiment of the present invention, as shown in
In a third embodiment of the present invention, as shown in
In a fourth embodiment of the present invention, as shown in
In a fifth embodiment of the present invention, as shown in
In a sixth embodiment of the present invention, as shown in
In a seventh embodiment of the present invention, as shown in
In an eighth embodiment of the present invention, as shown in
In a ninth embodiment of the present invention, as shown in
In a tenth embodiment of the present invention, as shown in
In an eleventh embodiment of the present invention, as shown in
It will be appreciated by those skilled in the art that mechanical fixing of the outer support webs and flanges can be carried out by any suitable means, for example by nails, staples, screws, bolts etc.
It will further be appreciated that each of the foregoing embodiments can be adapted or modified to include features of any of the other embodiments. For example, the additional inner support web(s) of
Moreover, it will be appreciated by those skilled in the art that the integrity of the flanges affects the structural qualities of a support beam. In particular, the connection of the outer support webs to the flanges is an important area in terms of structural integrity. For example, the absence of grooves, recesses and cut out portions in otherwise rectangular shaped flanges (e.g. see
The support beams of the present invention incorporate both structural and insulation qualities into a single member during manufacture thus achieving higher quality, more accurate thermal and/or sound efficiency and an increased level of structural support.
The structural beams of the present invention can also be produced in varying sizes and thickness depending on the particular application and insulation/structural requirements.
The material 110-1010 not only provides thermal and/or sound insulation, but also provides increased structural properties as demonstrated by
Samples of the aforementioned embodiments described above have been tested (under static compression) to establish their structural properties. The apparatus tested was:
(A) and (B) which are the support beams of FIGS. 2 and 1, i.e. with and without the infill of material 110 respectively;
(C) and (D) which are the support beam of
(E) and (F) which are the support beams of
(G) and (H) which are the support beams of
For all support beams, corresponding flanges were cut from Whitewood grade C16 timber. The corresponding outer support webs were cut from 11 mm thick OSB grade 3 panels and the infill material was 95 mm thick expanded polystyrene (EPS). All contact surfaces were glued together, and where appropriate, were screwed using 2×8 woodscrews.
In comparing the support beams with the infill of material (A, C, E and G) and without the infill of material (B, D, F and H), there is generally an increase in the ultimate load capacity and ductility of the support beams having the infill of material.
Advantageously, the infill material adds very little overall weight to each support beam, yet it provides a significantly increased ultimate load capacity.
Furthermore, the requirement for I-beams and box beams to have web stiffeners at areas prone to localised buckling may be dispensed with due to the increased ultimate load capacity of the support beams having the infill of material.
Moreover, the results shown in
In particular, supports beams (C) and (D) are worthy of further comment. The infill of material in support beam (C) exhibits an interesting quality in that it appears to affect the failure mode of the support beam. Although support beam (D) appears to fail suddenly at a displacement of approximately 4 mm, support beam (C) appears to initially fail at a displacement of approximately 5 mm yet can still hold the load applied for a further 4 mm of displacement. This shows the level of enhanced ductility provided by the infill material of support beam (C).
Overall the results clearly demonstrate that the addition of an inner support web connected between the flanges within the infill of material exhibit a far higher ultimate load capacity. From this result, it can be extrapolated that the addition of one or more inner support web(s) may increase the ultimate load capacity of any support beam design.
Having conducted the above tests,
The structural support beams of the present invention may be used in any building and construction projects. The support beams may be in the form of I-beams, double I-beams, box-beams, boxed I-beams or boxed double I-beams.
Modifications and improvements may be made to the above without departing from the scope of the present invention. For example, the infill material 110-1010 may be pre-fabricated, in which case, the respective outer support webs and flanges of a support frame may be bonded directly to the pre-fabricated material 110-1010. The infill material may be formed from either open cell, closed cell or a mixture of open and closed cell foam materials. Alternatively, the infill material may be formed from a wood-based material or any other suitable material providing the desired structural and/or thermal/sound insulating properties.
Alternatively, the material 10-1010 may be injected into a volume defined by a support frame of outer support webs and flanges, wherein the material expands to fill the volume. The respective contact surface of the support frame may have bonding means to assist on securing and ensuring a close contact with the infill of material 10-1010 to the support frame.
Claims
1. A structural support beam for use in building and construction comprising a support frame defining at least one volume, said support frame being of a first material and said at least one volume being in-filled with a second material.
2. A structural support beam as claimed in claim 1, wherein the support frame comprises two spaced apart flanges connected by at least two outer support webs.
3. A structural support beam as claimed in claim 2, wherein each outer support web connects lateral portions of the flanges.
4. A structural support beam as claimed in claim 2, wherein one or more additional outer support web(s) is/are positioned over one or both of the existing outer support webs.
5. A structural support beam as claimed in claim 2, wherein one or more inner support webs connect the flanges in an intermediate position between the outer support webs.
6. A structural support beam as claimed in claim 2, wherein one or more formations are provided in each flange to accommodate the outer support webs.
7. A structural support beam as claimed in claim 5, wherein one or more formations are provided in each flange to accommodate the inner support web or webs.
8. A structural support beam as claimed in claim 6, wherein the formations are one or more of grooves, recesses and cut-out portions.
9. A structural support beam as clamed in claim 2, wherein the flanges are rectangular in shape.
10. A structural support beam as claimed in claim 9, wherein each flange in fully interposed between the outer support webs.
11. A structural support beam as claimed in claim 2, wherein each flange is provided with a reduced width portion to define a T-shaped flange.
12. A structural support beam as claimed in claim 11, where in each reduced width portion is fully interposed between the outer support webs.
13. A structural support beam as claimed in claim 11, wherein the lateral edges of the other portions are adapted to be flush with the outer surfaces of the outer support webs.
14. A structural support beam as claimed in claim 11, wherein the lateral edges of the other portions are adapted to extend beyond the outer surfaces of the outer support webs.
15. A structural support beam as claimed in claim 2, wherein a further end-flange is connected to the outer end of each existing flange.
16. A structural support beam as claimed in claim 15, wherein the lateral edges of each end-flange are adapted to be flush with the outer surfaces of the outer support webs.
17. A structural support beam as claimed in claim 15, wherein the lateral edges of each end-flange are adapted to extend beyond the outermost surfaces of the outer support webs.
18. A structural support beam as claimed in claim 2, wherein metal end plates are connected to the outer end of each flange.
19. A structural support beam as claimed in claim 15, wherein metal end plates are connected to the outer end of each end-flange.
20. A structural support beam as claimed in claim 1, wherein the second material is less dense than the first material.
21. A structural support beam as claimed in claim 1, wherein the second material is a plastics foam material.
22. A structural support beam as claimed in claim 1, wherein the second material is adapted to give the support beam improved thermal and/or sound insulating properties.
23. A structural support beam as claimed in claim 1, wherein the second material is adapted to give the support beam improved structural properties.
24. A structural support beam as claimed in claim 1, wherein the support frame is made from timber materials.
25. A structural support beam for use in building and construction comprising a timber based support frame formed from two spaced apart rectangular flanges connected by at least two outer support webs wherein the timber based support frame defines at least one volume in-filled with a plastics foam material; and wherein the plastics foam material; and wherein the plastics foam material is bonded to the flanges and webs.
26. A structural support beam as claimed in claim 25, wherein the outer support webs extend over the full depth of the flanges.
27. A structural support beam as claimed in claim 25, wherein the flanges are formed from solid or laminated timber material and the webs are formed from timber sheet material.
28. A method of manufacturing the structural support beam of claim 1, said method comprising the steps of:
- (i) connecting two spaced apart flanges by means of at least two outer support webs to form a support frame defining at least one volume; and
- (ii) filling said at least one flume with an in-fill of material.
29. The method of claim 25, further comprising the additional step of bonding said in-fill of material to the support frame.
30. The method of claim 25, further comprising the additional step of gluing and/or mechanically fixing the outer support webs to the flanges.
Type: Application
Filed: Aug 16, 2004
Publication Date: May 17, 2007
Inventors: Abdolghaffar Kermani (Edinburgh), Ali Bahadori Jahromi (Worcestershire)
Application Number: 10/568,293
International Classification: E04C 3/30 (20060101);