WO2007109846A1

WO2007109846A1 - Precast wall panel

Info

Publication number: WO2007109846A1
Application number: PCT/AU2007/000384
Authority: WO
Inventors: Bruce Upton
Original assignee: Upstream Investments Limited
Priority date: 2006-03-28
Filing date: 2007-03-27
Publication date: 2007-10-04
Also published as: AU2007231542A1; EP2004924A1

Abstract

A cementitious precast wall panel comprises upper and lower edges and opposite first and second major surfaces interconnecting the upper and lower edges. At least the first major surface is profiled to promote airflow along that surface towards the upper edge. The profiling may incorporate a plurality of airflow channels to promote the airflow along that surface. Also provided is a wall system comprising a plurality of said precast wall panels and a plurality of facing sheet overlaying the respective first surfaces of the wall panels. The wall system is configured such that the airflow channels on the first surfaces promote airflow along the first surfaces to at least one outlet vent.

Description

PRECAST WALL PANEL

Technical Field

The present invention relates to wall panels and more specifically to precast wall panels. The invention has particular application for wall panels for use in building construction and the invention is herein described in that context. However, it is to be appreciated that the invention has broader application, such as civil infrastructure, and is therefore not limited to that use.

Background of the Invention

Pre-cast wall panels are widely used in building construction and are typically made from concrete or other cementitious material . An advantage of using precast panels, rather than conventional brick or block construction is that they can reduce the construction time. The panels may be load bearing and used to support the roof structure and may also be combined with sheeting materials to form a cavity wall.

Summary of the Invention

In a first aspect, the present invention provides a cementitious pre-cast wall panel comprising upper and lower edges and opposite first and second major surfaces interconnecting the upper and lower edges, wherein at least the first major surface is profiled to promote airflow along that surface towards the upper edge . Cementitious material is a porous substance and it has been found that when precast wall panels are used in cavity wall construction it is important to promote air flow in the cavity to reduce moisture build up in the wall.

In an alternative embodiment, both major surfaces are profiled to promote air flow along their respective surfaces towards the upper edge.

In a particular embodiment, the profiling on the or each major surface incorporates a plurality of air flow channels to promote the air flow along that surface.

In one form, the air flow channels extend from, or adjacent to, the lower edge to the upper edge. In one form, the air flow channels are linear along at least a substantial part of their length.

In a particular embodiment, the panel incorporates at least one bearing element disposed adjacent the upper end and projecting from at least the first major surface. In one form of this, the airflow channels extend about the bearing element to the upper edge .

In a particular embodiment, profiling on at least one of the major surfaces includes alternating crests and troughs defining the plurality of airflow channels. In one form, the profiling on at least one of the major surfaces extends along only a part of the width of the panel . In another form, at least substantially all the first or second major surface is profiled. The lower edge of the panel may be suitable for being mounted to an underlying structure in use . In one form, this lower edge of the panel is made plain. In other forms, the lower edge of panel is shaped to include one or more interfitting recesses or projections that locate in corresponding recesses or projections in a base structure. In one form of this latter arrangement, the lower edge of the panel is rebated.

In one form, the second major surface is generally planar and as such is ideally suited to be used as an external surface. The second major surface may be coated with a paint finish as is known in the art.

In a further aspect, the present invention provides a wall panel assembly comprising a wall panel as otherwise described in the above first aspect, and a plurality of mounting elements that extend outwardly from the first major surface, the mounting elements being arranged to receive one or more facing sheets thereon. In one form, these mounting elements are an elongated component extending substantially from one edge of a panel to an opposite edge of the panel. However, the mounting elements may be replaced in another embodiment by a row of spaced apart, short lengths of the elongate mounting element. Thus, the term "mounting elements" as herein is to be construed not only as single elongated items but also a functionally equivalent row of spaced apart, shorter sections of such items. In one form, these mounting elements are embedded into the cast panel.

The wall panel assembly may further comprise a lining where the lining locates adjacent to at least one of the major surfaces to define at least one airflow zone.

In a further aspect, the present invention provides a wall system comprising a plurality of pre-cast cementitious wall panels, the wall panels comprising opposite first and second major surfaces, upper and lower edges and opposite side edges extending between said upper and lower edges, the panels being arranged with the sides in edge to edge relation; a plurality of facing sheets overlaying the first surface of the wall panels; and at least one outlet vent, wherein the first surface is profiled to promote air flow along the first surface to the to the at least one outlet vent .

The wall panel may be arranged with the at least one outlet vent .

In one form, the lower region of the facing sheet is arranged with at least one inlet vent to further promote air flow along the first major surface towards the upper edge.

The upper region of the facing sheet may be arranged with at least one vent to further promote air flow along the first major surface.

In one embodiment of the wall system, the wall panel is as otherwise described in the above first aspect.

In one embodiment of the wall system, the wall panel is a wall panel assembly as otherwise described in the above second aspect . The lining may define at least one airflow zone and at least one service zone.

In one configuration, the wall system may comprise one or more external walls, each said external wall comprising one said wall panel, wherein either the first or the second major surface is configured to face an exterior region in relation to the external wall.

In a further aspect, the present invention provides a method for installing a wall system using the wall panel described above, the method including:

(a) preparing an underlying structure having one or more recesses or projections; and (b) mounting a lower edge of the wall panel to the underlying structure .

Brief Description of the Drawings

Notwithstanding any other forms which may fall within its scope, embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of an embodiment of a cementitious pre-cast wall panel in accordance with an embodiment of the invention;

Fig. 2 is a front elevation view of the wall panel shown in Fig. 1_/

Fig. 3 is a cross-sectional view of the wall panel of Fig. 1 taken on line 3-3 shown in Fig. 2 ;

Fig. 4 is a perspective view of an embodiment of a wall panel assembly in accordance with an embodiment of the invention; Fig. 5 is a cross-sectional view of the wall panel assembly of Fig. 4 taken on line 5-5 shown in Fig. 4; Fig. 6 is a part-sectional, side view of a wall system in accordance with an embodiment of the invention; Fig. 7 is a cross-sectional view of an alternative embodiment of the wall panel illustrated in Fig. 2;

Fig. 8 is an alternative embodiment of the wall panel assembly illustrated in Fig. 4;

Fig. 9 is a cross-sectional view of the assembly of Fig. 8 taken on line 9-9 shown in Fig. 8;

Fig. 10 is a cross-sectional view of an alternative embodiment of the wall panel illustrated in Fig. 2 ;

Figs. 11 and 12 are cross-sectional views of an embodiment of a wall panel assembly in use; and Fig. 13 is a part-sectional, side view of a wall system in accordance with another embodiment of the invention.

Modes for Carrying Out the Invention

Referring to the drawings, Figs. 1 and 2 show a wall panel 10 which is made of a cementitious material that has been pre-cast. The wall panel 10 is of a generally rectangular shape in profile and relatively thin in cross- section. The panel 10 includes an upper edge 12 and a lower edge 14. The panel 10 also is defined by two parallel and opposing side edges 36, 37. The panel 10 has a first major surface in the form of a front face 16 and an opposite, second major surface in the form of a back face 28 (not shown) . Substantially all of the front face

16 is profiled. The profiling in the embodiment shown has alternating crests and troughs forming linear elongate ribs 18 with intermediate channels 20 that extend generally from the lower edge 14 to the upper edge 12 of the wall panel 10.

The wall panel 10 is profiled to include a bearing element generally arranged at the upper in use edge 12. In use the bearing element of the wall panel 10 carries the load of an overlaying structure, for example a floor, roof beam, ceiling panel etc, by distributing the compression force load across a plurality of rectangularly-shaped corbels 22 which extend across the width of the panel 10 at the upper edge 12 and which project from the front face 16. The corbels 22 shown are spaced apart from each other and in between each corbel 22 a rib 18 and at least one air flow channel 20 is located.

The lower edge 14 of the wall panel 10 is designed to be suitable for mounting on a base structure. The particular details of the mounting will depend on the application for which the panel is being used. Generally the wall panel 10 can either rest on or within the base structure being used. In the illustrated form, the lower edge 14 of the wall panel 10 is rebated, with a profile which includes a projection 26 that can engage with a corresponding recess 27 in the base structure 29 (as shown in Figure 6) . When the wall panel 10 is intended to rest on a base structure 29 without necessarily engaging with that base structure 29, the lower edge can be made plain (i.e. without a rebate 26). However in other embodiments, the lower edge of the wall panel may include an alternative edge form which anchors the wall panel in position, thus preventing the wall panel from pivoting out of a desired alignment, or to accommodate the distribution of a load bearing force . Therefore, whilst the wall panel 10 has been disclosed with linear elongate ribs 18 and intermediate channels 20, it is to be appreciated that in further embodiments the profile may extend continuously or in a discontinuous manner along the first major surface. The wall panel may also be profiled using alternative patterns which form discrete series of alternating crests and troughs. Furthermore, an alternative form may involve the profile extending along only a part of the width of the panel .

The wall panel 10, as a cast product, can be constructed from many types of castable materials. Generally materials used for precast panels, such as cement and blends thereof as are known in the art, are suitable materials of construction. However the wall panel can be constructed from most forms of cementitious material, i.e. those materials which can provide the requisite strength for a support structure when set. By using an appropriate mould, the overall shape of the wall panel 10 can be cast into any desired configuration. In a typical casting process the mould would be configured to impress a desired profile onto the first major surface 16. At the same time as a profile is impressed on the first major surface 16, the shape of the upper 12 and lower edges 14 and one or more bearing elements 22 are also formed.

The overall length, width and depth of the wall panel may be made varied to suit the particular application. Depending on the application at hand the wall panel may include a decorative paint or other functional surface coating, such as a protective sealant, on the first major surface .

The front face 16 may include other features that provide the wall panel 10 with additional functionality. For convenience, and for ease of reference, in Figures 4 and 5 like features to those shown in the embodiment of Figures 1 to 3 have been designated with like reference numerals. Referring to Figures 4 and 5, the wall panel 10 is shown as an assembly 30 fitted with four spaced apart mounting elements in the form of elongated C-section brackets 32 which are partially embedded in the front face 16 of the wall panel 10. The brackets 32 extend outwardly from the front face 16. The brackets 32 may be embedded at the time of forming the wall panel 10 itself (i.e. inserted when the panel 10 is wet moulded) , or afterwards by physical attachment (e.g. gluing, drilling and bolting etc) .

In other embodiments, the wall panel may be arranged to incorporate a bracket of another shape, or some other desired functional element. The brackets 32 can be arranged on or at the panel 10 to receive one or more facing sheets (as will shortly be described in relation to Figure 6) .

Referring to Figures 8 and S₁ where like reference numerals denote like parts, instead of the elongate C- section brackets 32 which extend over almost the full length of the panel 10 (as shown in Figure 4) , a plurality of discrete, shorter-length C-section brackets 32' can be used instead. These shorter, spaced apart brackets 32' are aligned in rows 33, but alternatively may be placed in a staggered or any other suitable formation spaced across the width of the panel. The rows 33 of brackets 32' form an array of brackets 32', in this embodiment in staggered form. In an alternative arrangement, the brackets 32' are in a regular array.

In still further embodiments, the mounting elements can be in the form of clips, pins, angle sections, and the like, suitable for mounting facing sheets (and other like structures) to the assembly 30. The pre-assembly of the wall panel with any of the aforementioned types of mounting elements can assist in reducing construction time by keeping costly on-site modifications to the panels and related installation activities to a minimum. An additional benefit of reduced on-site installation time is the reduction of exposure of the panels and mounting elements to inclement weather and potential water damage.

In use, the wall panel 10 is combined as part of a wall system in the form of a building side wall 34, as is shown in Figure 6. In the building side wall 34, a plurality of assembles 30 (each comprising a wall panel 10 and respective bracket (s) 32) are arranged co-planar, with respective adjacent sides 36, 37 in edge to edge relation, allowing a plurality of facing sheets 38 to be overlaid over the front face 16 of the wall panel (s) 10 and spaced apart therefrom by the bracket (s) 32. Leading faces 39 of one or more of the brackets 32, 32' (e.g. see Figs. 8, 9) may comprise one or more connection means such as threaded portions or threaded couplers utilising a toggle joint, to facilitate connection of the facing sheets 38 to the panel 10. The combination of the ribs 18 and channels 20 on the face 16 of the panel 10 in use serve to increase the effective surface area of the face 16 when compared to the surface area of the same sized wall panel that has a planar surface, and to provide a route by which air can be moved or funnelled across the panel 10 when used in part of a more complex structure, such as a building wall cavity, for example. Air that is proximate to the front face 16 can in use be funnelled through the channels 20. The relatively increased effective surface area on the face 16 also provides a relatively greater projected surface area presented to insulation material, when used. This relatively increased surface area increases the effectiveness of the insulation used in this embodiment compared to an arrangement using a same size planar wall panel used in place of the profiled panel 10 of this embodiment, together with the same amount of insulation. Further benefits may be provided by the arrangement of this embodiment. For example, the insulation material as presented to the surface of the panel may be uninterrupted in its progression from top to bottom thereby enabling the travel of moisture/condensation therethrough, and the ribs 18 and channels 20 may enable the placement of services amongst the insulation material . In an alternative arrangement, the ribs 18 and channels 20 on the face 16 may also serve to provide, in addition to airflow channels, cavities for building services, such as water, electricity and information technology services. This would allow for a reduction or elimination of the need for the projection of furring channels.

In the embodiment of the wall panel 10 shown in Figure 3, the ribs 18 and intermediate channels 20 are evenly distributed across the width of the panel 10. The back face 28 of the panel is planar. Depending on the use of the wall panel, i.e. an external or an internal structure for a building, the back face 28 may be embellished with a decorative finish or functional structure. It is therefore possible for the back face 28 to consist of other suitable geometric forms.

In the embodiment illustrated in Fig. 7, where like reference numerals denote like parts, the back face 28' is profiled in a similar manner to the front face 16, comprising ribs 18' and channels 20'. This may be useful where the panel 10' is used as an internal wall, and it is desired to fix plasterboard to both sides of the panel 10' . As will be understood, the embodiment illustrated in Figure 7 may include the brackets described above with respect to either of Figures 4 and 8, and other described alternative embodiments thereof also described. The channels 20 on each side of the panel 10' of this embodiment promote airflow on each side to enable moisture received by the plasterboard to pass to the ceiling space. In the alternative embodiments utilising brackets 32, 32', the furring channels created when plasterboard is affixed to the brackets 32, 32' increase the space available for services.

Referring to the building side wall 34 shown in Figure 6, a furring channel 35, acting as an air cavity is defined by the front face 16 of the panel (s) 10 and a planar face 40 of the facing sheet (s) 38. Air can be moved via a hole or grille 50 located in the facing sheet (s) 38 to flow though the furring channel 35 and along the front face lδ via the channels 20 so as to flow past the corbels 22 and thus to exit the side wall 34 in region close to the top of the side wall 34. An air exit (located at the uppermost in use ends of the channels 20 of the panel 10) is shown as item 52. With planar pre-cast panels, moisture is known to build up in an enclosed air cavity in a wall, and this moisture generally condenses on the surface of the precast wall panel. This is sometimes referred to as "sweating" . By contrast, in the embodiments shown herein, air flow is channelled over the front face 16 (which itself has a high surface area) towards the upper edge 12 of the panel 10 to assist in the removal of moisture build up which may occur.

In Fig. 6 the air flow is shown as proceeding upwards through the furring channel 35. The direction of the air flow may be promoted by natural convection in the cavity. Convection of the air in the furring channel 35 of the building side wall 34 may also be achieved in other forms, such having mechanical means for creation of a draught.

Figure 10 illustrates an alternative embodiment, where like reference numerals denote like parts, where the panel 10" is used for an external wall. In this embodiment, the side 16" of the panel 10" facing the exterior of the structure of which it is part comprises the ribs 18 and channels 20 arranged to receive one or more external facing sheets or cladding, such as waterproofing cladding. Also, similarly with respect to the above described embodiments, the space between the panel 10 and the cladding could be used for insulation and/or services as well as ventilation airflow. This embodiment could also be configured with the brackets 32 or 32' of the above described embodiments for the cladding to be attached thereto. This embodiment may be useful in extrerne c1imates .

Referring to Fig. 11, use of brackets 32 (or 32') with a facing sheet 38 affixed thereto provides a furring channel 35 therebetween. As illustrated in Fig. 12, the furring channel 35 may provide additional space for insulation 44 and services 46 to be placed between the panel 10 and the facing sheet 38. For example, the services 46 may include water, electrical or information technology services. In this embodiment, as illustrated in Fig. 12, the channels 20 defined by the ribs 18 are left open to perform the function of allowing airflow therein. The insulation 44 fill in the furring channel 35 is kept from the channels 20 in this embodiment by a lining in the form of an open mesh barrier 48. In an alternative embodiment the lining may comprise a perforated plastic barrier 48 for example. The open mesh barrier 48 allows fluid communication between the furring channel 35 and the channels 20; the regions of the two channels 35, 20 may be considered as "zones", where the region of channels 20 between the front face 16 and the open mesh barrier 48 are an "airflow zone" . The region of the furring channel 35 between the barrier 48 and the facing sheet 38 is a

"services and/or insulation zone" . It is preferred, though not essential, that the airflow zone of the channels 20 be kept free of insulation material and services so as not to impede airflow therethrough. Indeed, as described above, the insulation and services may be placed in or at the channels 20, in which case the mesh barrier 48 would not be required. For example, the furring channel 35 and the channels 20 in the embodiment of Figure 11 could be filled with insulation material and could be used for provision of services .

As will be understood, the spaced brackets 32' illustrated in Figure 8 further allow cross movement of air and moisture between adjacent furring channels 35 and insulation 44 on either side of the brackets 32', unlike the brackets 32 of the embodiment illustrated in Figure 4.

In alternative arrangements, the wall panel can itself have one or more through holes positioned therein to facilitate the movement of air out of the furring channel 35 in a building side wall assembly which uses the wall panel. For example, Fig. 13 illustrates an alternative arrangement of the wall panel system in use compared with the wall panel described above with respect to Fig. 6, and where like reference numerals denote like parts. In this arrangement the external wall 54 comprises an external vent 56 at a low level. Internal vents 58a, 58b in the facing sheet are placed at high and low levels, respectively, on the wall . Means for moving air in the channels 20, such as a fan powered by mains electricity or solar power, may be employed to increase air flow in the channels 20. For example, the fan could be placed near a high level external vent 60 to draw air from the channels 20.

A substantial advantage of the profiling on the front face 16 is that the resultant furring channel 35, created when the wall panel 10 is installed as part of a building side wall 34, can have a greater volume as a result of the channels 20 formed along the front face 16 when compared to a wall cavity which uses a wall panel having a planar inner surface. The profiling of the front face 16 on the wall panel 10 permits the resultant furring channel 35 to hold a greater volume of the air and also provides a means for the entrapped air to egress or be ventilated from the furring channel 35. The greater volume of air in the furring channel 35 has a greater capacity to absorb moisture build up generated from environmental effects, such as temperature, rain and humidity.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Variations and modifications may be made to the parts previously described without departing from the spirit or ambit of the invention.

Claims

CLAIMS :

1. A cementitious pre-cast wall panel comprising upper and lower edges and opposite first and second major surfaces interconnecting the upper and lower edges, wherein at least the first major surface is profiled to promote airflow along that surface towards the upper edge.

2. A wall panel according to claim 1, wherein the second major surface is generally planar.

3. A wall panel according to claim 1, wherein both major surfaces are profiled to promote air flow along their respective surfaces towards the upper edge.

4. A wall panel according to any one of claims 1 to 3, wherein the profiling on the or each major surface incorporates a plurality of air flow channels to promote the air flow along that surface.

5. A wall panel according to claim 4, wherein the air flow channels extend from, or adjacent to, the lower edge to the upper edge .

6. A wall panel according to either claim 4 or 5, wherein the air flow channels are linear along at least a substantial part of their length.

7. A wall panel according to any one of claims 4 to 6, wherein the panel incorporates at least one bearing element disposed adjacent the upper end and projecting from at least the first major surface.

8. A wall panel according to claim 7, wherein the airflow channels extend about the bearing element to the upper edge.

9. A wall panel according to any one of claims 4 to 8, wherein profiling on at least one of the major surfaces includes alternating crests and troughs defining the plurality of airflow channels.

10. A wall panel according to any preceding claim, wherein the profiling on at least one of the major surfaces extends along only a part of the width of the panel.

11. A wall panel according to any preceding claim, wherein at least substantially all the first major surface or the second major surface is profiled.

12. A wall panel according to any preceding claim, wherein the lower edge of the panel is suitable for being mounted to an underlying structure in use .

13. A wall panel according to claim 12, wherein the lower edge of the panel is made plain.

14. A wall panel according to claim 12, wherein the lower edge of panel is shaped to include one or more interfitting recesses or projections that locate in corresponding recesses or projections in a base structure.

15. A wall panel according to claim 14, wherein the lower edge of the panel is rebated.

16. A wall panel assembly comprising a wall panel according to any one of the preceding claims, and a plurality of mounting elements that extend outwardly from at least one of the major surfaces, the mounting elements being arranged to receive one or more facing sheets thereon.

17. A wall panel assembly according to claim 15, wherein the mounting elements comprise components extending outwardly from at least the first major surface in a regular or a staggered array.

18. A wall panel assembly according to claim 17, wherein a distal end of at least some of the components comprises a connector for connecting to a facing sheet.

19. A wall panel assembly according to claim 16, wherein the mounting elements comprise an elongated component extending substantially from one edge of a panel to an opposite edge of the panel .

20. A wall panel assembly according to any one of claims 16 to 19, wherein the mounting elements are embedded into the panel .

21. A wall panel assembly according to any one of claims 16 to 20, further comprising a lining where the lining locates adjacent to at least one of the major surfaces to define at least one airflow zone.

22. A wall panel assembly according to claim 21, wherein the lining is permeable.

23. A wall system comprising: a plurality of pre-cast cementitious wall panels, the wall panels comprising opposite first and second major surfaces, upper and lower edges and opposite side edges extending between said upper and lower edges, the panels being arranged with the sides in edge to edge relation; a plurality of facing sheets overlaying the first surface of the wall panels; and at least one outlet vent, wherein the first surface is profiled to promote air flow along the first surface to the at least one outlet vent.

24, A wall system according to claim 23, wherein the wall panel is arranged with the at least one outlet vent..

25. A wall system according to claim 23 or 24, wherein the lower region of the facing sheet is arranged with at least one inlet vent to further promote air flow along the first major surface towards the upper edge.

26. A wall system according to any one of claims 23 to

25, wherein upper region of the facing sheet is arranged with at least one vent to further promote air flow along the first major surface.

27. A wall system according to any one of claims 23 to

26, wherein the wall panel is as otherwise defined in any one of claims 1 to 15.

28. A wall system according to any one of claims 23 to 26, wherein the wall panel is a wall panel assembly as otherwise defined in any one of claims 16 to 21.

29. A wall system according to any one of claims 23 to 28, comprising a lining on or at the first surface of the wall panel, the lining defining at least one airflow zone between the first surface and the lining, and at least one service zone between the lining and the facing sheet.

30. A wall system according to any one of claims 23 to 29, comprising one or more external walls, each said external wall comprising one said wall panel, wherein either the first or the second major surface is configured to face an exterior region in relation to the external wall.

31. A method for installing a wall system using the wall panel defined in any one of the preceding claims including :

(a) preparing an underlying structure having one or more recesses or projections/

(b) mounting a lower edge of the wall panel to the underlying structure.

32. A wall panel substantially as herein described with reference to the accompanying drawings .

33. A wall panel assembly substantially as herein described with reference to the accompanying drawings .

34. A wall system substantially as herein described with reference to the accompanying drawings .

35. A method substantially as herein described with reference to the accompanying drawings .