GB2355024A

GB2355024A - Insulating building panel of polystyrene and concrete

Info

Publication number: GB2355024A
Application number: GB9920727A
Authority: GB
Inventors: Roger Alfred Bullivant
Original assignee: Roxbury Ltd
Current assignee: Roxbury Ltd
Priority date: 1999-09-03
Filing date: 1999-09-03
Publication date: 2001-04-11
Also published as: GB9920727D0

Abstract

A building panel 10 has an insulating polystyrene foam layer 12 covered by a layer of concrete 14. The foam layer 12 has a series of peaks 12a and troughs 12b providing a mould into which the concrete 14 is cast or poured. Metal reinforcing bars 16 are located within the concrete 14 in each valley 12b to add strength. The panel 10 is suitable for use as a floor slab or a wall panel.

Description

2355024 Buildina Pane This invention relates to a building panel,

particularly, but not exclusively, a building panel suitable for use as a floor slab or a wall panel.

Building panels for use in modern construction techniques are desirably large, to minimise construction costs, but this results in them being heavy, difficult and expensive to transport. Such building panels are also often of relatively complex shape and section, which can make the panels difficult to fabricate.

According to the present invention there is provided a building panel comprising an insulation layer covered by a layer of cementitious material, the layer of cementitious material being cast onto a non-planar surface of the insulation layer, the said surface forming a mould for shaping the layer of cementitious material.

The insulation layer preferably comprises a polymer foam layer. The polymer foam is preferably polystyrene.

Desirably, the height of the insulation layer varies across the insulation layer. The height preferably varies substantially periodically in at least one direction across the insulation layer, and includes a plurality of peaks with valleys therebetween. The peaks and valleys desirably extend longitudinally along the direction generally perpendicular to the one direction. Preferably, the width of each peak in the one direction is substantially the same as the width of each valley in the one direction. The shape of a valley may be the inverted equivalent of the shape of a peak. Alternatively, the width of each peak may be greater or smaller than the width of each valley. The peaks and valleys preferably have a truncated triangle section in the one direction. Alternatively, the peaks may have a generally inverted U-shaped section.

Preferably, the thickness of the insulation material varies as the height of 2 the insulation layer varies, each peak consisting solely of insulation material. Alternatively, the thickness of the insulation may remain substantially constant across the insulation layer, as the height of the insulation layer varies, each peak being substantially hollow.

Desirably, a shutter peak having a height greater than that of the other peaks, is provided along at least one edge of the insulation layer. The shutter peak preferably comprises a peak cut into two halves down the height of the peak, one half remaining attached to the insulation layer and the other half being inverted and placed over the one half and partially filling the adjacent valley.

Alternatively, the insulation layer may comprise a single peak with lower height sections along at least one side.

Further alternatively, shaping means may be provided along at least one side of the insulation layer during fabrication of the panel, for shaping the one side of the panel. The shaping means are desirably removably locatable, such that the shaping means may be removed once the cementitious layer is cast. The said side of the panel is preferably shaped to enable a shear key to be provided between adjacent panels.

The insulation layer preferably additionally includes at least two forming peaks, each having a greater height than the other peak or peaks, for forming an integral beam of cementitious material on top of the cementitious layer of the panel. The forming peaks preferably extend along the longitudinal direction of the lower peak or peaks. A shutter peak may be a forming peak.

The insulation layer may further additionally include a forming channel for forming a beam of cementitious material extending across the peak or peaks, preferably in the one direction, within the panel. The forming channel is preferably cut into the insulation layer, preferably to the same depth as the valleys.

3 The cementitious material is preferably a pourable cementitious material. The cementitious material is preferably pourable concrete.

Preferably reinforcing members are provided in one or more of the valleys in the panel. The reinforcing members are desirably metal bars.

A crack inducer may be included at one or more points within the cementitious material of the panel to allow the panel to be broken up into a plurality of smaller panel sections.

A layer of gas impermeable material may be provided within the panel for preventing the migration or seepage of gas through the panel. The gas impermeable material may be between the insulation layer and the layer of cementitious material, or may form an outer surface of the panel. The gas impermeable layer preferably extends across substantially the full area of the panel. The gas impermeable material preferably comprises a polymer membrane. The gas impermeable material may alternatively comprise a member of a composite material or a metal, such as aluminium.

The present invention further provides a method of forming a building panel, in which a layer of cementitious material is cast onto an insulation layer, and covers the insulation layer, to form the panel.

The insulation layer is preferably as described in paragraphs four to twelve above.

The cementitious material is preferably a pourable cementitious material. The cementitious material is preferably pourable concrete.

Preferably, the insulation layer and a quantity of pourable cementitious material are transported to a construction site. Preferably, at the construction site, a quantity of pourable cementitious material is poured onto the insulation layer, to cover the insulation layer.

4 The cementit6us material is preferably vibrated to thereby aid distribution and settling of the cementitious material. Further quantities of cementitious material may be poured onto the insulation layer, and vibrated as aforesaid, until the insulation layer is covered by a desired quantity of cementitious material, and until the valleys between any two forming peaks present are substantially filled with cementitious materiaL A reinf orcing member, such as a metal bar, may be placed within the cementitious material in one or more of the valleys. A crack inducer may be placed within the cementitious material at one or more locations within the panel, thereby enabling the panel to be broken up into a plurality of smaller panel sections. Preferably, once the insulation layer is covered by the desired quantity of cementitious material the cementitious material is allowed to set.

The panel is preferably manufactured in situ at the site of final use of the panel. The panel may be manufactured with the insulation layer in direct contact with the ground. Alternatively, the panel may be manufactured with the insulation layer situated on top of at least one preformed beam member. A second panel may be manufactured directly on top of a panel, enabling a stack of panels to be manufactured.

The panel may alternatively be manufactured at a site distant to the site of final use, the panel then being transported to the site of final use.

A specific example of the invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic sectional view of a panel according to the present invention; Figure 2 is a diagrammatic sectional view of the panel of figure 1 having a shutter peak provided at one end thereof; Figure 3 is a diagrammatic sectional view of the panel of figure 1 including an integral beam formed between two former peaks; Figure 4 is dftrammatic view of a foam layer, suitable for use in manufacturing the panel of figure 1, having a former channel provided thereacross for forming an integral beam within the panel; Figure 5 is a diagrammatic sectional view of an alternative panel according to the present invention; Figure 6 is a diagrammatic sectional view of a further alternative panel according to the present invention; Figure 7 is a schematic representation of a plurality of panels according to the present invention fabricated on top of a larger panel according to the present invention; and Figure 8 is a schematic representation of an arrangement of two panels according to figure I having a shear key provided th&ebetween.

Referring to the drawings there is provided a building panel 10, 30, 40 comprising a polystyrene foam layer 12, 24, 32, 42 covered by a layer of concrete 14. As shown in figures I to 6, the height of the foam layer 12, 24, 32, 42 varies across the panel 10, 30, 40.

Figure 1 shows a panel 10 in which the foam layer 12 comprises a series of solid peaks 12a and valleys 12b. In this example the peaks 12a have a truncated triangle section. The profile of the valleys 12b is an inverted truncated triangle, which in this example is of the same outline as the peaks. The foam layer 12 is covered by a layer of concrete 14 which fills the valleys 12b and covers the tops of the peaks 12a of the foam layer 12. A metal reinforcing bar 16 is located within the concrete 14 in each of the valleys 12b to add strength to the panel 10.

One edge 10a of the panel 10 is shaped to allow a shear key to be fabricated between two adjacent panels 10 of this type, as will be described in more detail hereinafter. During fabrication of the panel 10, shaping means (not shown) are located adjacent one edge of the foam layer 12, for shaping the concrete 14 as the concrete layer is cast onto the foam layer 12. Once the concrete 14 is cast the shaping means are removed.

6 Figure 2 depicts the other edge 10b of the panel 10 of figure 1. A shutter peak 18 is provided at the edge 10b of the panel 10. The height of the shutter peak 18 is greater than the height of the other peaks 12a, to provide a shutter for the concrete layer 14. The shutter peak 18 is generally rectangular in overall section and comprises two halves 18a, 18b. The shutter peak 18 may be constructed as follows. The peak 12a located at the edge 10b of the foam layer 12 is cut in half at a vertical plane from the top of the triangle to its base. One half 18a of the peak 12a remains integral with the remainder of the foam layer 12. The second half 18b, cut from the edge of the foam layer 12, is turned upside down and placed over the first half 18a, the second half 18b being located within, and partially filling, the valley 12b adjacent the first half 18a. In this example, the peaks and valleys have the same outline, and the outline is complementary with itself, so that the two halves 18a,18b are a close fit together, leaving a vertical shutter surface facing the concrete 14, at about the mid-point of the outermost valley 12b.

Use of a shutter peak 18 allows the panel 10 to be fabricated using pourable conrete 14, as will be described in more detail hereinafter.

Referring to figure 3, the foam layer 12 may be adapted to allow fabrication of an integral beam 20 on the panel 10. In this example, the foam layer 12 includes two peaks 22 having a height greater than that of the other peaks 12a and of the concrete layer 14. The valley between the extra height peaks 22 is filled with concrete to form an integral concrete beam 20 on top of the concrete layer 14, running parallel with, and integral with, the concrete of that valley. Shuttering could also be provided to form a beam running in other directions.

As shown in figure 4, the foam layer 24 may be further adapted to allow fabrication of an integral beam running across the panel 10 and located within the panel 10. The foam layer 24 is shaped to include a forming channel 26 which extends across the foam layer 24, cutting into the peaks 12a. The forming channel 26 is filled with concrete 14 during fabrication of a panel 10 7 thereby forming a concrete beam across and within the panel 10. Although shown as perpendicular to the valleys 12b, the channel 26 could extend in other directions.

An alternative panel 30 according to the present invention is shown in figure 5. In this example the foam layer 32 comprises a series of hollow peaks 32a and valleys 32b. The peaks 32a have a generally inverted Ushaped section. The width of the peaks 32a is about twice the width of the valleys 32b. The foam layer 32 is covered by a layer of concrete 14. A metal reinforcing bar 16 is located within the concrete 14 in each of the gaps 32b to add strength to the panel 30.

The panel 30 is bounded at either side by a shutter peak 34. The shutter peaks 34 extend above the height of the other peaks 32a, to define the maximum height of the concrete layer 14. The presence of the shutter peaks 34 allows the panel 30 to be fabricated using pourable concrete 14, as will be described in more detail hereinafter.

One end of a further alternative panel 40 according to the present invention is shown in figure 6. In this example the foam layer 42 comprises a body section 42a of substantially constant height, edge sections 42b of reduced height, and tapering intermediate sections 42c therebetween. The body section 42a, intermediate section 42c and part of the edge section 42b of the foam layer 42 are covered by a layer of concrete 14.

A precast concrete beam 44 is located along the edge of the panel 40, on part of the edge section 42b. The precast beam 44 may be a wall beam. The precast beam 44 defines the edge of the panel 40, provides strength to the panel and support for other structures, such as walls, and acts as a shutter to define the maximum height of the concrete layer 14.

The aforementioned panels 10, 30, 40 may be fabricated using a method of manufacturing a building panel provided by the present invention, as follows.

8 Firstly a polystyrene foam layer 12, 24, 32, 42 is fabricated, using known methods of fabricating and shaping polystyrene foam. In particular, hot wire cutting can be used to form two foam layers 12 from a single sheet of polystyrene. The foam layer 12, 24, 32, 42 is then transported to a construction site, which may be the site at which the panel 10, 30, 40 will be finally used in the construction of a building. A quantity of pourable concrete is also transported to the construction site. The foam layer 12, 24, 32, 42 is placed directly on the ground, with the peaks uppermost ready to receive the concrete layer 14.

Alternatively, the panel 10,30,40 may be fabricated at a site remote from the site where the building is to be constructed, the panel 10,30,40 being transported to the building construction site once the panel 10,30, 40 has been fabricated.

A panel such as the one shown in figure 1 is manufactured as follows. A shutter peak 18 is constructed, as described above, at each edge of the foam layer 12. This may be done before or after the foam layer 12 is placed in position on the ground. A first quantity of pourable concrete is poured into each valley 12b in the foam layer 12, to partially fill each valley 12b. The concrete is then vibrated to aid distribution and settling of the concrete. Next a metal reinforcing bar 16 is placed in each valley 12b on top of the concrete.

A further quantity of concrete is then poured over the foam layer 12, covering the reinforcing bar 16, and vibrated as aforesaid. The steps of pouring and vibrating the concrete are repeated until the concrete layer 14 is completed, being generally level with the top of the shutter peaks 18. If the foam layer 12 includes extra height peaks 22, a further amount of concrete is poured into the valley or valleys between the extra height peaks 22 to thereby form a concrete beam 20 on top of the concrete layer.

During these operations, the foam is forming a mould to shape the final form of the concrete, and is non-planar to create the features described.

9 Once the desifed amount of concrete has been poured over the foam layer 12 the concrete is allowed to set. The insulating properties of the polystyrene foam layer 12 assist in controlling the rate of loss of heat from the concrete during the setting process and thus assists in controlling the rate at which the concrete layer sets. This is particularly advantageous when the ground and/or air temperature is cold, such as during winter months, because the presence of the insulating foam layer prevents the concrete from losing heat too rapidly, and hence setting too quickly, which can result in the concrete not forming correctly. When the concrete is set the panel 10 is complete and is ready for use.

A panel such as that shown in figure 5 may be manufactured by following the same steps of pouring concrete into the valleys 32b in the foam layer 32, vibrating the concrete, placing a metal reinforcing bar 16 in each valley 32b, and then repeating the steps of pouring and vibrating concrete until the concrete layer 14 is level with the top of the shutter peaks 34. The concrete is then allowed to set, as before, to produce the final panel 30.

The panel 40 shown in figure 6 may be manufactured as follows. A precast beam 44, such as a wall beam, is laid along each of the edges of the foam layer 42, on the edge sections 42b of the foam layer 42. The precast beam 44 acts as a shutter. A first quantity of concrete is poured over the foam layer 42, following which the concrete is vibrated to aid distribution and settling. Further quantities of concrete are then poured over the foam layer 42 and vibrated as before until the concrete layer 14 is generally level with the top of the precast beam 44. The concrete 14 is then allowed to set, as before, to produce the final panel 40.

Crack inducers may be included in any of the above mentioned panels 10, 30, 40 to enable the panels 10, 30, 40 to be broken up into smaller panel sections. The crack inducers are located on the peaks 12a, 32a of the panels 10, 30 of figures 1 and 5, and on the body section 42a of the panel 40 of figure 6, before concrete is poured over the peaks 12a, 32a and the body section 42a.

As shown in figure 7, a panel stack 50 may be produced using this method of manufacturing building panels. In this example, the panel stack 50 comprises a plurality of panels 54, 56, 58, 60, 62, 64 manufactured on top of a larger panel 52 which acts as a floor panel. This enables the panels 54-64 to be used in the so called 'tilt up' method of building construction in which, for example, wall panels 54-64 of a building are manufactured in situ on top of the floor panel 52 of the building and are then tilted upright to form the walls of the building.

Two panels 10,70 of the type shown in figure 1 may be arranged side by side, as shown in figure 8, to enable a shear key 72 to be formed between the two panels 10,70. The shear key 72 comprises screed, and is constructed using a known method of constructing shear keys.

There is thus provided a building panel of relatively straightforward construction, and a method of manufacturing such a building panel.

Various modifications may be made without departing from the scope of the present invention. For example, the insulation layer may be fabricated from a polymer foam other than polystyrene. The insulation layer may be of a different shape to the examples described, and may be of any required size. In particular, the peaks and valleys may be of a sectional shape different to those shown. The shutter peaks may be of a different shape and construction. The extra height peaks may be of any height relative to the height of the panel and may have a different sectional shape to that shown. Any number of extra height peaks may be provided on the foam layer. A single extra height peak may be used in conjunction with a shutter peak to form a beam along an edge. The shaping of the panel edges for forming a shear key may be of a different shape to that described.

A panel such as those shown in figures I and 5 may have a reinforcing member provided in each valley or in only a selected number of valleys. A panel such as that shown in figure 6 may include one or more reinforcing 11 members. The reinforcing members may have a different form to that described.

The cementitious material may be a material other than concrete. The concrete layer may not always extend to the top of the shutter peak or precast beam. The position of the reinforcing members within the concrete layer may be different to that described.

Various modifications may be made to method of manufacturing a construction panel without departing from the scope of the present invention. For example, the insulation layer and the cementitious material may be transported to the construction site separately or together. The construction site may be a site remote from the site of final use of the panel. The whole of the desired quantity of concrete may be poured over the insulation layer in one step. The concrete may not always need to be vibrated after pouring. The reinforcing members and crack inducers, when present, may be placed in the panel before the concrete is poured over the insulation layer, during pouring of the concrete or after the concrete has been poured.

It will be appreciated that the building panel and method of manufacturing a building panel illustrated in the specific embodiments of this invention offer several advantages. The presence of the insulation layer provides an insulation layer within the panel, allowing straightforward construction of a building having insulated walls and/or floors. There is no need to arrange and construct a separate insulating layer/skin on the walls and floors of a building, as is required in a building constructed using conventional building materials.

Because the method illustrated allows a building panel to be manufactured at the site where a building is to be constructed, the cost of transporting the construction materials, the insulation layer and pourable concrete, to the building site is reduced in comparison to the cost of transporting the equivalent amount of conventional building materials.

12 It will be further appreciated that the illustrated method of fabricating a building panel at the site where it is to be used is particularly advantageous in relation to large panels, such as floor panels, which are cumbersome, difficult and expensive to transport. Smaller panels, such as wall panels, may be fabricated on site, in situ, or at a remote fabrication site and then transported to the construction site.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

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Claims

1. A building panel comprising an insulation layer covered by a layer of cementitious material, the layer of cementitious material being cast onto a nonplanar surface of the insulation layer, the said surface forming a mould for shaping the layer of cementitious material.

2. A panel according to claim 1, wherein the insulation layer comprises a polymer foam layer.

3. A panel according to claim 2, wherein the polymer foam is polystyrene.

4. A panel according to any preceding claim, wherein the height of the insulation layer varies across the insulation layer.

S. A panel according to claim 4, wherein the height varies substantially periodically in at least one direction across the insulation layer, and includes a plurality of peaks with valleys therebetween.

6. A panel according to claim 5, wherein the peaks and valleys extend longitudinally along the direction generally perpendicular to the one direction.

7. A panel according to claim 5 or 6, wherein the width of each peak in the one direction is substantially the same as the width of each valley in the one direction.

8. A panel according to claim 5, 6 or 7, wherein the shape of a valley is the inverted equivalent of the shape of a peak.

9. A panel according to claim 5, 6 or 7, wherein the width of each peak is greater or smaller than the width of each valley.

10. A panel according to any of claims 5 to 9, wherein the peaks and valleys 14 have a truncated triangle section in the one direction.

11. A panel according to any of claims S to 9, wherein the peaks may have a generally inverted U-shaped section.

12. A panel according to any of claims 5 to 11, wherein the thickness of the insulation material varies as the height of the insulation layer varies, each peak consisting solely of insulation material.

13. A panel according to any of claims 5 to 11, wherein the thickness of the insulation remains substantially constant across the insulation layer, as the height of the insulation layer varies, each peak being substantially hollow.

14. A panel according to any of claims 5 to 13, wherein a shutter peak is provided along at least one edge of the insulation layer, the shutter peak having a height greater than that of the other peaks.

15. A panel according to claim 14, wherein the shutter peak comprises a peak cut into two halves down the height of the peak, one half remaining attached to the insulation layer and the other half being inverted and placed over the one half and partially filling the adjacent valley.

16. A panel according to any of claims 5 to 14, wherein the insulation layer comprises a single peak with lower height sections along at least one side.

17. A panel according to any of claims 5 to 16, wherein shaping means are provided along at least one side of the insulation layer during fabrication of the panel, for shaping the one side of the panel.

18. A panel according to claim 17, wherein the shaping means are removably locatable, such that the shaping means may be removed once the cementitious layer is cast.

19. A panel according to claim 17 or 18, wherein the said side of the panel is is shaped to enable a shear key to be provided between adjacent panels.

20. A panel according to any of claims 5 to 19, wherein the insulation layer additionally includes at least two forming peaks, each having a greater height than the other peak or peaks, for forming an integral beam of cementitious material on top of the cementitious layer of the panel.

21. A panel according to claim 20, wherein the forming peaks extend along the longitudinal direction of the lower peak or peaks within the panel.

22. A panel according to claim 20 or 21, wherein a shutter peak forms a forming peak.

23. A panel according to claims 5 to 22, wherein the insulation layer further provides a forming channel for forming a beam of cementitious material extending across the peak or peaks.

24. A panel according to claim 23, wherein the channel extends in the said one direction.

25. A panel according to claim 23 or 24, wherein the forming channel is cut into the insulation layer.

26. A panel according to claim 25, wherein the forming channel is cut to the same depth as the valleys.

27. A panel according to any of claims 5 to 26, wherein reinforcing members are provided in one or more of the valleys in the panel.

28. A panel according to claim 27, wherein the reinforcing members are metal bars.

29. A panel according to any preceding claim, wherein the cementitious material is a pourable cementitious material.

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30. A panel according to claim 29, wherein the cementitious material is pourable concrete.

31. A panel according to any preceding claim, wherein a crack inducer is included at one or more points within the cementitious material of the panel to allow the panel to be broken up into a plurality of smaller panel sections.

32. A panel according to any preceding claim, wherein a layer of gas impermeable material is provided within the panel for preventing the migration or seepage of gas through the panel.

33. A panel according to claim 32, wherein the gas impermeable material is between the insulation layer and the layer of cementitious material.

34. A panel according to claim 32, wherein the gas impermeable layer forms an outer surface of the panel.

35. A panel according to any of claims 32 to 34, wherein the gas impermeable layer extends across substantially the full area of the panel.

36. A panel according to any of claims 32 to 35, wherein the gas impermeable material comprises a polymer membrane.

37. A panel according to any of claims 33 to 35, wherein the gas impermeable material is comprises a member of a composite material or a metal.

38. A panel according to claim 37, wherein the material is aluminium.

39. A method of forming a building panel, in which a layer of cementitious material is cast onto an insulation layer, and covers the insulation layer, to form the panel.

40. A method according to claim 3 9, wherein the insulation layer has the 17 features set out in any of claims 2 to 26 as described in paragraphs four to twelve above.

41. A method according to claim 39 or 40, wherein the cementitious material is a pourable cementitious material.

42. A method according to claim 41, wherein the cementitious material is pourable concrete.

43. A method according to claim 41 or 42, wherein the insulation layer and a quantity of pourable cementitious material are separately transported to a construction site.

44. A method according to any of claims 39 to 43, wherein the cementitious material is vibrated as it is poured, to thereby aid distribution and settling of the cementitious material.

45. A method according to 44, wherein further quantities of cementitious material are subsequently poured onto the insulation layer, and vibrated as aforesaid, until the insulation layer is covered by a desired quantity of cementitious material.

46. A method according to any of claims 39 to 45, wherein a reinforcing member, such as a metal bar, is placed within the cementitious material in one or more of the valleys.

47. A method according to claim 46, wherein the reinforcing member is a metal bar.

48. A method according to any of claims 39 to 47, wherein a crack inducer is placed within the cementitious material at one or more locations within the panel, thereby enabling the panel to be broken up into a plurality of smaller panel sections.

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49. A method according to any of claims 39 to 43, wherein the panel is manufactured in situ at the site of final use of the panel.

50. A method according to any of claims 39 to 43, wherein the panel is manufactured with the insulation layer in direct contact with the ground.

51. A method according to claims 39 to 43, wherein the panel is manufactured with the insulation layer situated on top of at least one preformed beam member.

52. A method according to claim 51, wherein the second panel is manufactured directly on top of a panel, enabling a stack of panels to be manufactured.

53. A building panel substantially as described above, with reference to the accompanying drawings.

54. A method of forming a building panel, substantially as described above with reference to the accompanying drawings.

55. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.