NZ543429A - Lightweight simulated brick panel - Google Patents

Abstract

A lightweight prefabricated simulated brick panel (10) is disclosed. The panel is formed from a foundation (12) and a façade (14), with the façade presenting the appearance of a conventionally laid brick surface (18). The foundation includes an array of voids (28) extending from a first edge to a second edge to significantly reduce the weight of the panel. The panel also includes toothed end formations to allow interlocking of adjacent panels.

Description

1 NEW ZEALAND PATENT ACT 1953 COMPLETE SPECIFICATION LIGHTWEIGHT SIMULATED BRICK PANEL The invention is described in the following statement, including the best method of performing it known to us: 40 45 MyRef: 130151 1 Invention Title: LIGHTWEIGHT SIMULATED BRICK PANEL The present invention relates to pre-fabricated building components and, more particularly, to pre-formed wall or paving fabrication systems.

BACKGROUND Masonry brick walls have been known and used in domestic buildings, community Buildings and commercial buildings for hundreds years. More recently, walls simulating a masonry brick appearance have also gained considerable acceptance. Already in the market, are a number of products that offering masonry facing for pre-existing walls. Most of these are attached to a vertical surface of a wall by fasteners or suitable adhesive. These products generally need to be made on site, therefore requiring a relatively large flat surface acting as support on which to fabricate them. Such generally large surface may not be available or adequate on site. Pre-cast products, are generally of heavy construction, complicated to manufacture, incurring significant transport costs and therefore relatively expensive.

Know in the art is GB1432584 - A.A Thornton & Co / David Vale -1976.

Method and Means for building Construction. This invention specifically relates to a method and means for domestic dwelling with expectancy on advancement in speed and economy on the building construction. The invention is a forming of non-structural wall panel consist of three main layers, the internal layer, the core layer and the external layer which comprises blocks or discs that are adhered to the backing sheet to simulate the regular "brick wall pattern" and or the irregular one. Therefore, on site, this wall panel is built of minimum 4 different building products that individually "pre-manufactured". 3 This invention of non structural panel is installed on site within the timber studs and wall plates of timber wall frames structure. 80 The invention involves intensive on-site works in constructing the panel especially the time and labour consume to construct the regular or irregular conventional "brick pattern" of the blocks / discs that adhered to the backed sheet one by one.

Known in the art is US4644719 (Salazar - 1987) for a Decorative Wall panel. This invention specifically relates to materials and techniques making decorative wall panels, which can be applied to a variety of wall structures. These relatively thin decorative wall panels are made on site and comprise a continuous base layer of cementation materials and patterned layer bonded to the surface of the base layer. The installation of the panels is by attachment to a preexisting wall structure by fasteners. Disadvantages "onsite fabrication" is specified above on 90 lines 64, 65 & 66. Another disadvantage of such thin panels is that they can not be self supporting or load bearing. Nor can they offer the thermal property advantages of a conventional brick wall.

US4183188 (Goldsby - 1980) discloses a Simulated Brick Panel Composition and 95 Method. This invention again relates to a pre-cast decorative building panel simulating a brick wall. This invention is to produce a panel having plurality of metal reinforcement members moulded within panel. Installation of the panels is to a pre-existing vertical surface, for example by driving nails through the panels. Thus these panels likewise cannot be considered self supporting or load bearing. 100 3 4 US3304673 (Ramoneda - 1967) discloses a Simulated Brick structure. The invention relates to precast wall sections. The sections comprise 3 separate panels, a front panel, core 105 panel and inner panel. The front panel comprises 2 layers; a base layer and simulated brick face layer. The construction is relatively complex and requires several different mould configurations to cater respectively for flat wall sections, corners and joiner elements. The individual panels are clearly very heavy and would require heavy lifting equipment to raise and position them.

It is an object of the present invention to address or ameliorate some of the above disadvantages.

Note The term comprising (and grammatically variations thereof) is used in this 115 specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of'.

£ BRIEF DESCRIPTION OF INVENTION Accordingly, in a first broad form of the invention, there is provided a prefabricated, 120 interlocking lightweight simulated brick panel comprising a foundation and a facade; said facade formed so as to present the appearance and texture of a laid brick surface; said foundation provided with an array of voids extending through said foundation from a first edge of said panel to an opposite second edge.

Preferably, said facade comprises a plurality of courses of brick shaped formations 125 projecting from said foundation. 4 Preferably, said brick shaped formations are of a depth and length equivalent to the depth and length of standard building bricks. 130 Preferably, combined thickness of said foundation and said facade are equivalent to thickness of a conventional laid brick wall.

Preferably, said courses and said brick shaped formations are separated by pointing; dimensions of said pointing equivalent to dimensions of pointing of a standard laid brick wall.

Preferably, alternate courses are horizontally offset one to another by one half brick 1^^ shaped formation.

Preferably, horizontal offset of said courses provides at least one end portion of said panel with a toothed formation; said toothed formation adapted for interlocking of adjoining ones of said panel so as to form a desired length of simulated brick panel.

Preferably, said panel may be formed with one said toothed formation at each of first 140 end and a second opposite end of said panel.

Preferably, said panel may be formed with one said toothed formation at a first end and a straight edge at a second of said panel.

Preferably, said voids are adapted to reduce the weight of said panel.

Preferably, said voids are adapted to accept structural reinforcing elements 145 throughout.

Preferably, said reinforcing elements comprise concrete poured into said voids after erection of said panel to form a wall.

Preferably, said reinforcing elements comprise a combination of concrete and steel reinforcing rods. 150 Preferably, said voids are adapted to accept load bearing elements throughout.

Preferably, said foundation is moulded of lightweight concrete material. 6 Preferably, said pointing comprises a layer of suitably coloured material bonded to surface of said foundation. 155 Preferably, said brick-shaped formation are moulded of a powdered clay- fired brick material bonded to said layer.

Preferably, said brick-shaped formations are moulded of a lightweight concrete material.

Preferably, one said panel is joined to an adjoining said panel by a suitable bonding agent.

Preferably, selected panel configurations are moulded in selected moulds.

Preferably, said selected moulds comprise sets of moulds; each set of moulds of said set of moulds comprising a foundation mould and facade mould.

Preferably, said sets of moulds include at least: 165 a. a set for moulding a panel with toothed formation at each end said panel. b. a set for moulding a panel for moulding a panel having a toothed formation at one end only of said panel. c. a set for moulding a panel having straight edges at each end of said panel. Preferably, said foundation mould comprises a tray provided with raised side and 170 end portions of a depth equal to the thickness of said base portion.

Preferably, a said foundation mould may be provided with blocking elements at each end of a said tray to provide said toothed formation at each end of said panel.

Preferably, said foundation mould may be provided with blocking elements at one end of said tray to provide said toothed formation at one end only of said panel. 175 Preferably, any said foundation mould may be provided with blocking elements to reduce in number said brick-shaped formations in at least one said course of said panel. 7 Preferably, any said foundation mould may be provided with blocking elements to reduce in number said courses of said panel. 180 Preferably, said facade mould comprises a grid; said confirming to jointings between said courses and brick-shaped formations of a said panel.

Preferably, said grid is formed of rectangular section; said grid so located relative upper edges of said raised edges of said tray of a said foundation mould so as to allow a layer of jointing material to flow between a surface defined by said upper edges and undersides of said 1 rectangular sections.

Preferably, open spaces defined by said grid conform to said brick-shaped formation.

In a further broad form of the invention there is provided a method for moulding the said simulated brick panels comprising the steps of: 190 a. determining panels required for a predetermined area, b. arranging said moulds for said foundations of said panels on a supporting surface, c. filling said moulds for said foundations with a suitable foundation material, d. arranging said moulds for said facade in registration with each of said moulds 195 for said foundation, e. filling said mould for said facade with a layer of said jointing material to a first level, f. filling openings in a grid forming said mould with a simulated brick material. 200 7 8 Preferably, said determining of said panels required for walls of said building include the steps of: 205 a. representing each wall of said building in a CAD package, b. dividing each wall of said building into sections comprising whole numbers of courses and whole numbers of brick-shaped formations, c. determining moulds and mould configurations suitable for each of said sections. 2^^ In still a further broad form of the invention, there is provided a lightweight simulated brick panel including a foundation and a facade; said facade formed so as to present the appearance of a laid brick wall; said foundation provided with an array of voids extending through said foundation from a first edge to an opposite second edge so as to lighten said panel; and wherein adjoining ones of said panel are provided with a toothed end formation 215 adapted for interlocking of said adjoining ones of said panel so as to form a continuous simulated brick facade.

BRIEF DESCRIPTION OF DRAWINGS Embodiments of the present invention will now be described with reference to the 220 accompanying drawings wherein: Figurel is a front elevation view of preferred embodiment of a simulated brick panel section according to the invention, Figure 2 shows a rear view, plan view and end and sectioned views of the panel of Figure 1, 225 Figure 3 is a perspective view of the panel of Figures 1 and 2, 8 9 Figure 4 is a perspective view showing two of the panels of Figures 1 and 2 assembled together vertically, 230 Figure 5 is a perspective view showing two of the panels of Figures 1 and 2 assembled together horizontally, Figure 6 is a perspective view of two of the panels of Figures land 2 assembled to form a right angled corner Figure 7 shows various views of a facade mould for casting a first part of the panels 2^^ of Figures 1 and 2 Figure 8 shows various views of a facing mould for casting a second part of the panels of Figures 1 and 2 Figure 9 is an elevation view of the design of an exemplary fa?ade of a building to which the brick panels of the invention are to be applied 240 Figure 10 shows the fa?ade of figure 9 divided into a number of sections Figure 11 shows one of the sections of Figure 10 overlaid with a number of standard panel templates and one truncated panel template, Figure 12 shows further example of the sections of Figure 10 overlaid with panel templates, 245 Figure 13 is a plan view of an array of moulds comprising the section of figure 10 prepared on a manufacturing bench ready for moulding.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT With reference to Figures 1 to 3, and as best seen in Figures 2 and 3, a simulated 250 brick wall panel 10 forms a structural element of the brick wall construction system of the present invention. Panel 10 comprises a combination of foundation 12 and facade 14. Foundation 12 is 9 dimensioned and configured to simulate a number of courses of a section of brick wall, for example, eight courses of eight brick each; each brick course 16 being made up of a number of simulated 255 bricks 18 formed in facade 14.

The depth "A" and "length "B" of individual bricks 18 are equal to the equivalent dimensions of conventional bricks. Likewise, the combined thickness "C" of foundation 12 and facade 14 is equal to the thickness of a conventional laid brick wall. As best seen in Figure 2, the rear or inward facing surface 26 of wall panel 10 is flat.

Furthermore, the thickness and pointing of the simulated mortar jointing 20 between courses 16 and bricks 18 is equal to that used in conventional brickwork so that in all respects the dimensions and configuration of the panel 10 corresponds to an equivalent section of a conventionally laid brick wall having that number of courses and bricks per course.

As can be seen in Figure 1 to 3 the bricks 18 of successive courses 16 are offset by 265 half their length "B", again as in a conventional brick wall. Thus the first end 22 and second end 24 form a "toothed" arrangement. Every second course is one brick shorter than the preceding course so that with an even number of courses, of the two courses forming the uppermost course 22 and lowermost course 24, one will be one brick longer than the other.

Thus, by inverting alternate panels, successive panels may be placed one on the top of the other as 270 in Figure 4, or end to end to form a desired length of wall with the toothed ends interlocking as shown in Figure 5. The toothed arrangement at the ends of panel 10 also allow for two panels to be fitted together to form a corner of a building (as shown in Figure 6). Panels may also be formed with either a toothed formation at one end only, or with straight edges at both ends as more particularly described below. 275 With reference again to Figure 2 and 3, a feature of the construction of foundation 12 is the provision of an array of continuous vertical hollows or void 28 arranged at intervals along the 11 length of the panel 10. These may be of any desired shape, for example elliptical, but in any case are formed so as to not weaken panel 10 significantly while greatly reducing the weight of the panel. A further function of the voids 28 is that they may, subsequent to the erection of an assembly of panels, be filled with concrete, optionally with reinforcing rods.

The void 28 may in addition be used to house supporting structures, such as steel columns (not shown), to render the wall assembly load bearing in those embodiment of the panels where the materials used in their construction is not inherently load bearing.

The panel of the present invention are manufactured by mean of first and second moulds for the foundation 12 and facade 14 respectively. Three types or sets of corresponding foundation and facade moulds are envisaged; a first set providing for toothed formations at both ends of a panel, a second set providing a toothed formation at one end only, and third set with even edges at both ends.

In addition to the standard size trays, ancillary blocking elements (not shown) in the form of either a straight element or toothed blocking element are provide, which may be positioned in a tray to shorten the length of panel to be produced from that of a standard panel.

Blocking elements are provided to enable the number of courses to be reduced from that of a standard tray. This allows for the height of walls to any desired number of courses.

With reference now to Figure 7a, a facade mould 30 of the first type, comprises a generally rectangular tray 32 bounded by raised sides of height equal to thickness of foundation 12, that is to dimension "C" less the thickness of facade 14. At each end of the tray 32 are closed or blocked sections 34 corresponding to the toothed arrangement of panel 10 described above. Of these, the two outer blocked sections 34a and 34b at first end 36 and blocked sections 34c and 34d at second end 38 are provided with holes 40 adapted to provide registration for the second mould defining the grid pattern of jointing 20. 11 12 As shown in Figure 7b, the long sides 42 and 44 of tray 32 are provided with locating holes 46 adapted to locate and support cores 48 during the filling of the mould for creating the voids 28 of panel 10.

A second mould 50 is provided to form the pattern of jointing and brick faces of facade 14 of panel 10.

With reference to Figure 8, mould 50 comprises an interconnected grid of rectangular section 51 (as can be seen in the enlargement of figure 8a) defining the horizontal and vertical jointing 20 (Figures 1 and 3) between courses and bricks. The extent of the grid and the blocked section 52 correspond to the extent and blocked sections of the foundation mould 32 described above. Blocked section 52a and 52b at first end 54 and blocked sections 52c and 52d at second end 56, are provided with downwardly projecting nipples 58 for engagement with holes 40 provided in the corresponding blocked sections of foundation mould 32.

As can be seen from the enlargement of Figure 8a, the sections 51 of the grid defining the jointing between courses and bricks are raised some little distance above the periphery 60 of the mould when place over the foundation 26. This allows jointing material 62 representing the jointing 20 to flow under these sections. The open areas 64 may then be filled with brick simulating material 66.

DESIGN AND MANUFACTURE Preferably, panels are produced at a manufacturing facility prior to transporting to and erection at a building site. The manufacturing process is as follows: Stage 1. Design With reference to Figure 9, a fa?ade 100 of a building 110 to be constructed making use of the panels of the invention, is assessed for locations of openings, making adjustment to 12 13 arrange for lengths and heights to correspond to even numbers of bricks and courses.

The facade 100 is then divided into sections as shown in Figure 10 and labelled for identification for both the manufacturing phase and ultimate on-site erection. Each section is further divided into a number of standard panels and, where required a shorter end panel. The design process is most conveniently carried out by means of a computer aided design (CAD) package, which readily allows the fa?ade design to be rendered at 1:1 scale. This may then be superimposed by previously prepared standard brick patterned mould templates. This may then be identified by a reference code for position. Additionally, the code may reference a particular colour and / or brick texture.

An example of this division into mould panels is shown in Figure 11 where the lower section of the facade "RA" of Figure 10 has been divided into panels RAl to RAIO, with RAIO a shorter than standard panel.

Figure 12 shows a similar process for determining the arrangement of moulds for producing the sections RB and RC of Figure 10. Thus all sections of facade are prepared at the design stage so that the appropriate mould configurations can be used.

The finished drawing then becomes the "work sheet drawing" and print-outs of the design may then be used for both the manufacturing process and erection on site. Each moulded panel is provided during the mould process with an identifying batch and location code.

Stage 2. Manufacture Depending on the facilities available, trays may be filled individually, or arranged in large arrays for greater efficiency. Figure 13 shows a preferred manufacturing arrangement where a large surface area, or workbench 120 is adapted to arrange an array of trays for moulding. The bench is provided with fixed guide elements 122 and 124 along one end and one side respectively, 13 14 and with adjustable guide elements 126 and 128 to retain moulds 130 in position.

The required number of standard foundation moulds are positioned on the bench and 355 such blocking elements as indicated on the work sheet drawing placed in position.

Preferably, moulds are prepared prior to moulding with a spray-on release agent or lined with thin plastic sheeting to aid in the removal of moulded panels.

Foundation 26 is moulded from a lightweight concrete or similar material. The foundation moulds are first filled with this material, screed to a uniform flat surface and allowed to harden. 3^^ The facade moulds are then positioned over the foundations, locating each in the holes 40 of the foundation trays to ensure proper registration.

The material, also lightweight concrete or similar, suitably coloured to represent the jointing between the bricks, is then poured into the facing mould to the level of underside of the grid of rectangular section 51 as described above. If required, the surface of the foundation layer be 365 prepared with a suitable bonding agent prior to pouring the jointing layer.

Finally, when the jointing layer has sufficiently hardened, the brick shaped openings of the facade mould are filled with a brick simulating mixture to the top of the grid of rectangular sections. This mixture may bonding be composed of coarse brick powder in a suitable bonding matrix. 370 When the facing layer has properly hardened, the facade moulds are removed, the panels extracted from the trays and core formers removed. The panels may then be transported to the building site for erection.

ERECTION ON SITE 375 Erection on site is greatly simplified when compared to the erection of conventional laid brickwork. Following the directions of the work sheet drawing, panels may be handled by two 14 workers and placed into position on previously prepared footings or concrete slab. Individual panels are bonded together by means of suitable bonding agents or a strip adhesive such as for example the 380 prefabrication bonding compound MBC Strip adhesive such as the bonding compound MBC is applied to all edge surfaces of foundations of panels where two panels connect, that is both along the upper horizontal edge surface of the next panel as well as the surfaces of the toothed formations.

Where appropriate, void 28 may be prepared with reinforcing and filled with 3^^ concrete to aid in locking vertically adjoining panels together or to provide load bearing strength.

It will be appreciated that the wall design, manufacturing and erection processes of the present invention offer significant savings in both the amount and the skill of labour required, and moreover provide significant on-site cost and time savings.

Other cost savings and advantages provided by the panels of the present invention is 390 that for walls of buildings, smaller lintels or no lintels for windows and doors are required. As well, there is no requirement for cleaning after erection as is invariably the case with laid brick walls.

Although the above description is with reference to the use of the invention for walls of a building, it will be appreciated that the panels may equally be used for fencing, retaining walls and the like. Furthermore, the panels may be laid horizontally to form paved areas. 395 The above describes only some embodiments of the present invention and modification, obvious to those skilled in the art, can be made thereto without departing from the scope and spirit of the present invention. 400 16 405

Claims (31)

CLAIMS:

1. A prefabricated, interlocking and lightweight simulated brick panel comprising a foundation and a facade; said facade formed so as to present the appearance and 410 texture of a conventionally-laid brick surface; said foundation distinguished by an array of voids extending through said foundation from a first edge to an opposite second edge so as to lighten significantly said panel; whereupon a plurality of said panels are fitted such that by an interlocking system of a toothed end formation so as to form a continuous simulated brick fa9ade. 415

2. The panel of claim 1 wherein said facade comprises a plurality of courses of brick shaped formations projecting from said foundation.

3. The panel of claim 2 wherein said brick shaped formations are of a depth and length equivalent to the depth and length of standard building bricks.

4. The panel of any one of claims 1 to 3 wherein combined thickness of said foundation 420 and said facade are equivalent to thickness of a conventional laid brick wall.

5. The panel of any one of claims 2 to 3 wherein said courses and said brick shaped formations are separated by pointing; dimensions of said pointing equivalent to dimensions of pointing of a standard brick wall.

6. The panel of any one of claims 2 to 3 wherein alternate courses are horizontally 425 offset one to another by one half of one brick formation.

7. The panel of any one of claims 2, 5, 6 wherein horizontal offset of said courses provides at least one end portion of said panel with a toothed formation; said toothed formation adapted for interlocking of adjoining ones of said panel so as to form a desired length of simulated brick panel. 430 16 17

8. The panel of claim 7 wherein said panel may be formed with one said toothed formation at each of a first end and a second opposite end of said panel.

9. The panel of claim 7 wherein said panel may be formed with one said toothed 435 formation at a first end and a straight edge at a second end said panel.

10. The panel of any one of claims 1 to 9 wherein said voids are adapted to reduce the weight of said panel.

11. The panel of any one of claims 1 to 10 wherein said voids are adapted to accept structural reinforcing elements throughout. 440

12. The panel of claim 11 wherein said reinforcing elements comprise concrete poured into said voids after erection of said panels to form a wall.

13. The panel of claim 11 wherein said reinforcing elements comprise a combination of concrete and steel reinforcing rods.

14. The panel of any one of claims 1 to 9 wherein said voids are adapted to accept load 445 bearing elements throughout.

15. The panel of any one of claims 1 to 14 wherein said foundation is moulded of a lightweight concrete materials.

16. The panel of claim 5 wherein said pointing comprises a layer of suitably coloured material bonded to a surface of said foundation. 450

17. The panel of claim 16 wherein said brick-shaped formation are moulded of a powdered clay fired brick material bonded to said layer.

18. The panel of claim 16 wherein said brick-shaped formations are moulded of a lightweight concrete material.

19. The panel of any one of claims 1 to 18 wherein one said panel is joined to an 455 adjoining said panel by a suitable bonding agent. 17 18

20. The panel of any one of claims 2 to 19 wherein selected panel configurations are moulded in selected moulds.

21. The panel of claim 20 wherein said selected moulds comprise sets of moulds; each 460 set of moulds comprising a foundation mould and a facade mould.

22. The panel of claim 21 wherein said sets of moulds include at least (a) a set for moulding a panel with toothed formation at each end of said panel, (b) a set for moulding a panel having a toothed formation at one end 465 only of said panel, (c) a set for moulding a panel having straight edges at each end of said panel.

23. The panel of claim 21 or 22 wherein said foundation mould comprises a tray provided with raised side and end portion of a depth equal to the thickness of said 470 base portion.

24. The panel of any one claims 22 to 23 wherein a said foundation mould may be provided with blocking elements at each end of said tray to provide said toothed formation at each end of said panel.

25. The panel of any one of claims 22 to 23 wherein said foundation mould may be 475 provided with blocking elements at one end of said tray to provide said toothed formation at one end only of said panel.

26. The panel of any one of claims 21 to 25 wherein any said foundation mould may be provided with blocking elements to reduce in number said brick-shaped formations in at least one said course of said panel. 480 18 19

27. The panel of any one of claims 21 to 26 wherein any said foundation mould may be provided with blocking elements to reduce in number said courses of said panel.

28. The panel of claim 21 wherein said facade mould comprises a grid; said grid 485 confirming to jointing between said courses and said brick-shaped formations of a said panel.

29. The panel of claim 28 wherein said grid is formed of rectangular sections; said grid so located relative upper edges of said raised edges of said tray of a said foundation mould so as to allow a layer of jointing material to flow between a surface defined 490 by said upper edges and undersides of said rectangular sections.

30. The panel of claim 28 or 29 wherein open spaces defined by said grid conform to said brick-shaped formations.

31. A method for moulding the simulated brick panels of any one of claims 19 to 30 said method comprising the steps of: 495 (a) determining panels required for a predetermined area, (b) arranging said moulds for said foundations of said panels on a supporting surface, (c) filling said moulds for said foundations with a suitable foundation material, 500 (d) arranging said moulds for said facade in registration with each of said moulds for said foundation, (e) filling said mould for said facade with a layer of said jointing material to a first level, (f) filling openings in a grid forming said mould with a simulated brick 505 material. 19 20 The method of claim 31 wherein said determining of said panels required for walls of said building include the steps of: (a) representing each wall of said building in a CAD package, (b) dividing each wall of said building into sections comprising whole numbers of courses and whole numbers of brick-shaped formation, (c) determining moulds and mould configurations suitable for each of said sections. A prefabricated, interlocking and lightweight simulated brick panel comprising a foundation and a fa?ade; said facade formed so as to present the appearance and texture of a conventionally-laid brick surface; said foundation distinguished by an array of voids extending through said foundation from a first edge to an opposite sccond edge so as to lighten significantly said panel; whereupon a plurality of said panels are fitted such that by an interlocking system of a toothed end formation so as to form a continuous simulated brick fafade.. A prefabricated, interlocking and lightweight simulated brick panel as herein described and with reference to the accompanying drawings. Dated: 07 June 2007 By: Chan Wiryakusuma 16 EARLS AVENUE - RIVERWOOD NSW 2210 - AUSTRALIA PHONE: 61 02 9584 9869 MOBILE: 0407 607 937 EMAIL: chan.w@optusnet.com.au 20