The present invention relates to a building panel and wall construction made therefrom. In particular, the invention relates to a thermally insulating wall structure which finds particular application in buildings constructed in areas having extremes of either hot or cold, or both.
U.S. Pat. Nos. 5,667,190; 5,922,235; 6,186,469 and 6,186,469 (Scott/assignee Scott System Inc.) disclose a concrete panel of simulated brick appearance and various bracket devices for maintaining brick pavers in situ during formation of the concrete panel. Although such panels address problems caused by the scarcity of bricklayers, they do not address the thermal problems associated with conventional masonry structure.
In particular, the increasing price of energy and greenhouse gas consideration mean that the consumption of energy in both heating and cooling dwellings must be reduced. As a consequence, conventional masonry walls (including both double brick and brick veneer construction) are unable to meet the thermal insulation specification required of modem construction. For example, a brick veneer wall has an R rating of approximately 0.45-0.47, and a double brick wall has an R rating of approximately 0.5-0.52. Even with fiberglass insulation batts installed in the cavity of a brick veneer wall the R rating is only increased to approximately 1.5-2.0. However, modem building specifications call for an R rating for walls of approximately 3 or better.
Many forms of thermally insulating wall construction have been proposed, however, in order to be practical not only must the level of thermal insulation be good, but the wall must be structurally strong and easy to construct. Unless a particular wall construction meets all three of these desiderata, it is unlikely to be commercially successful.
The object of the present invention is to provide an improved wall construction which makes use of both the concept of a cavity wall, and also the thermally insulating properties of reflective sheets, for example those fabricated from metal foils or metal coated films.
In accordance with a first aspect of the present invention there is disclosed a thermally insulating wall construction comprising a pair of masonry panels each having an internal surface and an observable surface and being arranged with said internal surfaces facing each other to define an air cavity between said panels, said internal surfaces each having a plurality of recesses interspersed between protrusions, and said wall construction having at least one reflective sheet which extends between adjacent protrusions, and which is spaced from the interior of said recesses.
In accordance with a second aspect of the present invention there is disclosed a method of fabricating a panel for use in the abovementioned wall construction, said method comprising the steps of:
(i) creating a mould for said panel,
(ii) placing a shaped former in said mould to form said recesses and protrusions,
(iii) pouring a flowable hardenable cementitious substance onto said former within said mould and allowing same to set, and
(iv) removing said set material and former from said mould whereby said former is retained in situ in said panel.
In accordance with a third aspect of the present invention there is disclosed a masonry panel having an internal surface and an observable surface, said internal surface having a plurality of recesses interspersed between protrusions, and at least one reflective sheet which extends between adjacent protrusions and which is spaced from the interior of said recesses.
Several embodiments of the present invention will now be described with reference to the drawings in which:
As seen in
At their upper edges, the panels 5A and 5B are retained within an E-shaped galvanised cap plate 9. The cap plate 9 has a centrally located and longitudinally extending groove 10 the dimensions of which define the corresponding dimensions of an interior cavity 12 formed between the two panels 5A and 5B. Located in the slab 3 below the cavity 12 is a slot 13 within which, at spaced apart intervals along the length of the wall 1, a number of threaded rods 15 (only one of which is illustrated) are positioned. The rods 15 are maintained in a vertical orientation by means of a chemical anchor (such as a two part epoxy resin) which surrounds the lower end of each rod 15 and binds it with the slot 13. The upper end of each of the threaded rods 15 passes through a corresponding hole in the groove 10 and carries a nut 16 which enables the rod 15 to be placed in tension to thereby urge the cap plate 9 against the panels 5 which are thereby placed in compression. A length of sealing tape 18, which is illustrated in truncated fashion in
As seen in
Illustrated in cutaway fashion in
As best seen in
To those skilled in the thermally insulating arts, it will be apparent from
Turning now to
In a third embodiment illustrated in
Turning now to
In order to carry out the moulding procedure, firstly the side walls 203 and 204 are pivoted downwardly about hinges 220 so as to lie in a substantially horizontal position generally flush with the base 202. Then a planar and rectangular spacer 211 (which preferably takes the form of a fibre cement sheet 6 mm thick) is placed in the mould 201. The width of the spacer 211 is such that it does not reach quite to the hinges 220. Over the spacer 211 is laid a thin sheet of aluminium foil 228. Over the interior of each of the end walls and the side walls 203, 204 is located a layer of polyethylene film 219. Such film is widely used in kitchen applications to cover bowls of salad, etc which are placed in a domestic fridge. The purpose of the film 219 is simply to act as a release agent and ensure that the end walls and side walls 203, 204 are maintained clean between individual moulding applications. In particular, the film 219 extends over the hinges 220 so as to maintain same free of liquid cement during the moulding procedure. If the polyethylene film 219 is not used, commercially available spray on release agents can be used instead.
On top of the aluminium foil 228 is placed a dimpled or castellated sheet 227 fabricated from moulded or pressed paper or cardboard material. Such sheets 227 are widely used in the egg industry as one portion of a two portion container for eggs. Such sheets 227 are inexpensive and provide a convenient means of forming the desired pattern of protrusions and recesses on the interior surface of the panel 205. Such sheets 227 are also used for pears, apples, tomatoes etc and so a number of such sheets each with a different profile and/or dimensions, are available.
Once the film 219 and egg carton sheet 227 are in place, the side walls 203 and 204 are swung up into, and latched in, a vertical position in which they are substantially perpendicular to the base 202. Then lightweight concrete mixture 217 is poured into the mould 201 and on top of the egg carton sheet 227. Although the egg carton sheet 227 absorbs moisture from the concrete mixture, it is sufficiently strong to maintain the concrete 217 in position until it takes its first set. If desired, the egg carton sheet 227 can be treated by being sprayed with lacquer, varnish or similar to make same to some extent water impervious.
Once the lightweight concrete 217 has set, the side walls 203 are unlatched and pivoted about the hinges 220. This enables the solidified slab 205 to be lifted clear of the mould 201. The aluminium foil 228 comes away with the panel 205 and thus is formed together with the panel 205 and does not need to be added as a subsequent step.
In
If desired, the observable surfaces 222 of the panels 205A, 205B can be covered with a thin layer of lining board 236 (preferably 2.5 mm in thickness) which is glued to the panels 205 and provides a similar external appearance to that of plasterboard for a flush finish. The liner board 236 conveniently conceals the abutting edges of adjacent panels 205. Preferably to reduce acoustic and thermal transmission through the wall 200, the abutting edges of adjacent panels 205A are staggered, or are offset, relative to the abutting edges of adjacent panels 205B.
As before, the arrangement of the panels 205A and 205B means that there are many interfaces between the opposite observable sides of the wall 200 and thus an extremely high R rating (typically between 5 and 10) for the wall is able to be achieved which results in very low thermal transmission through the wall 200. The wall 200 also has a good acoustic performance, however, this can be improved by locating (as illustrated in
A still further embodiment is illustrated in
In particular, as indicated in
The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention. For example, the aluminium foil or film 28 can be perforated in the region of each crest 26 to allow an adhesive bonding cement to bond between the panels 5, through the foil or film 28 and on to the packing strip 31. The foil or film 28 preferably has some “memory” and can therefore be bent during handling but then return to the intended scalloped shape. Similarly, the grooves 24, 124 can be of any shape or profile. In addition, in multi-storey buildings, the rods 15 can be dispensed with as the upper floors maintain the panels 5 in compression. It will also be understood that in the drawings the scale of some objects such as the aluminium coated foil 28, 128, 228 and the film 219 is exaggerated in order to make same visible. Similarly, the masonry can be formed in ways other than by casting lightweight concrete, however, this is the most efficient.
The term “comprising” (and its grammatical variations) as used herein is used in the inclusive sense of “having” or “including” and not in the exclusive sense of “consisting only of”.
Number | Date | Country | Kind |
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2003904281 | Aug 2003 | AU | national |
2003904928 | Sep 2003 | AU | national |
2004900793 | Feb 2004 | AU | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AU04/01074 | 8/11/2004 | WO | 6/21/2006 |