AU750020B3 - A load bearing building panel - Google Patents

Description

P/00/011 Regulation 3.2 COMMONWEALTH OF AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: ONECRETE PTY LTD Russell Wells AHEARN FOX Patent Trade Mark Attorneys, GPO Box 1149 Brisbane, Queensland, 4001 A LOAD BEARING BUILDING PANEL The following statement is a full description of this invention, including the best method of performing it known to us: -1- A LOAD BEARING BUILDING PANEL This invention relates to a load bearing building panel.

This invention has particular but not exclusive application to a load bearing building panel made predominantly from light weight concrete which may be used in the construction of buildings, and wherein reference will be made to same.

Many buildings, including those used as dwellings, are built upon a foundation comprising a concrete slab. The external walls of the building typically are mounted on the peripheral edges of the concrete slab and may comprise a plurality of timber or metal 10 frames.

The external face of the frames is often concealed behind a suitable form of cladding, such as lengths of timber or panels constructed from light weight composite materials, including light weight concrete, which are fastened to the frames.

The internal face of the frames may also be concealed behind a suitable form of cladding, such as sheets of plaster board, that are fastened to the frames.

The frames also provide support for a roof structure and wherein elongate fasteners, known as tie rods, that extend through the frames, are often used to secure the roof structure directly to the foundation.

It will be appreciated that the aforementioned method of constructing a building is very time consuming and requires the co-ordination of different suppliers and tradesmen. Delays in the supply of materials and/or the availability of tradesmen can add greatly to the cost of the construction of the building. It is also noted that the quality of workmanship provided by -2different tradesmen may vary considerably and thereby may have a detrimental effect on the value of the building.

Other building methods, commonly referred to as "tilt-up construction", comprise walls manufactured from concrete. These are usually lifted into place on site with the aid of a crane.

Accordingly, while such methods of construction may be less time consuming than the more traditional method described above, the handling of heavy walls made of concrete is more hazardous.

The present invention is aimed at providing a load bearing building panel manufactured from a reinforced, light weight, concrete material which may be used in the construction of external walls of buildings and such like in place of the various methods of wall construction discussed above. It is envisaged that the load bearing building panel that is the subject of the present invention will be light enough that it may be located in position by either two tradesmen or with the aid of small lifting equipment, such as a bobcat, or other mechanical apparatus with a lifting arm attachment. Furthermore, the reinforcing in combination with the concrete shall resist imposed loading such as from roof, lintels and upper floors, and provide protection against lateral impact loads, such as may occur as a consequence of acts of vandalism, or due to flying debris during high wind and cyclonic conditions.

With the foregoing in view, this invention in one aspect resides broadly in a load bearing building panel, including: a body composed of a light weight concrete material, said body having an obverse face and an opposing reverse face, and two opposing side faces, said obverse face, reverse face and side -3faces being located intermediate opposing upper and lower faces; a first reinforcing contained within said body and located adjacent said obverse face, said first reinforcing extending through said body in the general direction of said upper and lower faces for at least much of the length of said body, said first reinforcing also extending through said body in the general direction of the side walls for at least much of the width of said body; a second reinforcing contained within said body and located adjacent said reverse face, said second reinforcing extending through said body in the general direction of said upper and lower faces for at least much of the length of said body, said second reinforcing also extending through said body in the general direction of said side walls for at least much of the width of said body, and wherein said first reinforcing and/or said second reinforcing includes both upper and lower engaging portions each of which are capable of at least partially extending about a fastener that extends through said body between said obverse and reverse faces.

The body may be any suitable shape. For example, the shape of the body may generally resemble a rectangularly shaped prism and wherein the obverse and reverse faces, the two side faces, and the upper and lower faces may lie in planes that are substantially parallel. However, it will be appreciated that the obverse and reverse faces, and/or the two side faces, and/or the upper and lower faces may lie in planes that are diverge.

The size of the body will generally be dependent upon individual job constraints such as ceiling heights, single or two -4story construction, roof loadings, design wind loadings, manual or machine positioning units, and the like. Nevertheless it is preferred that the upper and lower faces are each short narrow faces that are generally rectangular in shape. It is also Preferred that the two side faces are two long narrow faces that are generally rectangular in shape. Similarly it is preferred that the obverse and reverse faces are two long broad faces that are generally rectangular in shape. For example, the length of the body may vary between 1800mm and 3600mm; the width may vary between 300mm and 900mm, and the depth may vary between 70mm and 150mm.

Each face may generally comprise a single surface. By way of example, the surface may be substantially flat or it may be S curved.

Alternatively each face may include a plurality of surfaces.

o These surfaces may be either substantially flat or curved, or a a combination of both flat and curved surfaces.

The surfaces may have any suitable texture. For example, the surfaces may be generally rough or smooth, and may be rendered in a decorative matter, such as a surface finish that resembles rows of bricks.

The body may be manufactured from any suitable light weight concrete material including light weight concrete materials of the type that is referred to as "Autoclave Aerated Concrete".

The first and second reinforcing may each comprise a sheet of a reinforcing material, such as steel. The sheet may include one or more apertures formed therein and wherein these may be arranged in an ordered or random manner. For example, the reinforcing may resemble a mesh.

Alternatively the first and second reinforcing may each include a one or more elongate reinforcing members manufactured from a suitable material such as steel. For example, each reinforcing may comprise a plurality of rod like reinforcing members that may be interconnected together, such as by a welding process or using a plurality of wire ties. For example, rod like reinforcing members in combination with one another may form a mesh like structure.

In one embodiment, each of the engaging portions may comprise an aperture formed in the reinforcing. For example, the engaging portion may comprise an aperture formed in a sheet of o a closed or open material, such as a mesh like material.

Alternatively, each of the engaging portions may comprise a loop like reinforcing member that is attached to or forms an integral 0 part of the reinforcing.

As with panel sizes, steel reinforcement sizes will be dictated by the individual job constraints and the loading imposed.

In another aspect, this invention relates to a method of constructing a building, said method including: the provision of a foundation; the erection of one or more external walls comprising one or more load bearing building panels of the type described above, each panel being secured to the foundation by a fastener that is partially surrounded by a lower engaging portion; the placement of a roof structure on said external wall or external walls, said roof structure being secured to each load bearing building panel by a fastener that is partially surrounded by an upper engaging portion.

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein: FIG. 1 is a schematic isometric view of a load bearing building panel constructed in accordance with the present invention; FIG. 2 is a schematic isometric view of a reinforcing used in the construction of the load bearing building panel illustrated in figure 1; FIG. 3 is a side view of a building constructed in accordance with the present invention; FIG. 4 is a cross-sectional front view showing part of a G 15 wall of the of the building illustrated in figure 3, and FIG. 5 is a detailed isometric view showing a portion of the foundation of the building illustrated in figure 3.

Figure 1 shows a typical load bearing building panel 10 that for convenience is broken in the middle. The load bearing building panel or panel 10 includes a body 11 that generally resembles a rectangular shaped prism.

The body includes an obverse face 12 and an opposing reverse face 13, as well as two opposing side faces 14 and 15. The obverse face 12, reverse face 13 and the two side faces 14 and 15 are located intermediate opposing upper and lower faces 16 and 17 respectively.

The body also includes a first reinforcing 18 and a second -7reinforcing 19. The reinforcing 18 and the reinforcing 19 each comprise two sets of interconnected steel rod like members that are arranged so as to form a mesh like sheet. In particular the two sets of steel rods are arranged such that they are at degrees to each other, one set being substantially parallel to the edges of the panel 10, the other set being substantially parallel to the top and the base of the panel 10. Each reinforcing 18 and 19 also includes an upper engagement portion 21 and a lower engagement portion 22.

Each engagement portion 21 and 22 comprises a generally "U" shaped steel rod 23 that is welded to the mesh like sheet at points 24 along it's length. By way of example, the shaped steel rod is attached to the internal face of the reinforcing 18 or 19.

Preferably the "legs" 25 of the shaped steel rod 23 overlie the longitudinally extending steel rods from which the reinforcing is made. For example, the shaped steel rod 23a may be located approximately 50 mm from the upper face 16 (i.e.

mm cover), and overlies 300mm of the reinforcing. Similarly, the shaped steel rod 23b may be located approximately 125mm from the lower face 17(i.e. 125mm cover).

The body is constructed from a light weight concrete material, such as that which is referred to as "Autoclave Aerated Concrete", and wherein rectangular box shaped waterproof moulds may be used in the construction of same. These are required to hold the lightweight concrete while it sets or cures. Preferably these are capable of individual adjustment in length from 1800mm to 3600mm, in width from 300mm to 900mm, and in depth from to 150mm.

The first reinforcing 18 is cast in the panel 25mm to from the reverse or internal face 14 of the panel. The second reinforcing 19 is cast in the panel 10 approximately 25 mm to mm from the obverse or external face 13 of the panel. A minimum concrete cover distance from steel to external faces of concrete) of 30 mm is to be allowed to sides, top and base of panels.

Two metal or plastic sleeves having an internal diameter of 14mm and length varying from 70mm to 150mm, depending on panel thickness, are preferably cast in the panel to provide for a through bolt fixing to the top and the base of the panel. These sleeves are to be located equidistant from the sides of panel, one 75 mm from the centre of sleeve to top of panel, and the other 150 mm from the centre of sleeve to base of panel. In some panels, a 14mm diameter hole will be cast in the panel in lieu, in the same locations as above and with the same distances from hole centre to top of panel and base of panel.

Having filled the rectangular box shaped mould with a light weight concrete mix, the mix should be allowed to set or cure.

Figures 3, 4 and 5 show a portions of a typical building that comprises load bearing building panels 10 of the type described above.

The building includes a foundation 30 consisting of reinforced concrete footings 31 and a slab 32 which are laid in accordance with standard building practice, with a 310 mm high x sheet thickness plus 10mm wide step down formed around the full perimeter of the building. A 10mm thick leveling bed of mortar -9is laid over a damp proof course to the horizontal surface of this step down, and for the full perimeter of the building.

The reinforced lightweight concrete wall panel 10 is located and fixed with a proprietary adhesive to the leveling bed and temporarily propped as per conventional building practice. Then the panel 10 is bottom fixed with a single M12 stainless steel Trubolt 33 through the cast in metal or plastic sleeves, or 14mm diameter hole, and fixed 125 mm into slab face as illustrated in figure 3. The 10mm PCV packer 35 must be located over the Trubolt 33 prior to tightening.

Another reinforced lightweight concrete panel is then similarly located in place beside the first and vertical edge fixed to preceding panel with a proprietary adhesive, and in -o accordance with manufacturer's specification. Panel is then bottom fixed as per first panel. This procedure is continued o,% around the building's perimeter until all of the external walls are completed.

Window and door openings are constructed preferably using standard reinforced lightweight concrete lintels, having 450 bearing each end and M12 tie down rods each side of openings.

Over wider openings, e.g. double garage door openings, domestic steel-framed lintels are to be used with FC cladding externally to accept render finish.

When the panel bedding joint and vertical joint adhesive has set, interior domestic steel-framed bracing walls are to be installed at intervals not exceeding 9.0 to facilitate removal of temporary props. Liquid grout is then poured into the 10mm gap between case of wall panels and concrete slab to bond the two components together, which provides added strength.

A steel top plate 36 is now fixed in place by fasteners 37 to provide continuity of tie down to roof framing. The roof structure 38 in turn is secured to the top plates as illustrated.

Expansion or control joints are preferably placed at approx' 6.0 centres for the full perimeter of the reinforced lightweight concrete wall panels.

It will be appreciated that the light weight panels 10 may be located in place by two men or a bobcat and accordingly overcome some of the problems associated with tilt-up construction. Further, it will be appreciated that the method of construction described above is less labor intensive than more conventional methods of construction.

It will also be appreciated that the use of light weight concrete in the construction of the panels lessens the loading on the footings or lower structure of the building.

It will of course be realised that while the foregoing description has been given by way of example of this invention, all other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein defined in the appended claims.

Claims (3)

1. A load bearing building panel, including: a body composed of a light weight concrete material, said body having an obverse face and an opposing reverse face, and two opposing side faces, said obverse face, reverse face and side faces being located intermediate opposing upper and lower faces; a first reinforcing contained within said body and located adjacent said obverse face, said first reinforcing extending through said body in the general direction of said upper and lower faces for at least much of the length of said body, said first reinforcing also extending through said body in the general direction of the side walls for at least much of the width of said body; a second reinforcing contained within said body and located adjacent said reverse face, said second reinforcing extending through said body in the general direction of said upper and lower faces for at least much of the length of said body, said second reinforcing also extending through said body in the general direction of said side walls for at least much of the width of said body, and wherein said first reinforcing and/or said second reinforcing includes both upper and lower engaging portions each of which are capable of at least partially extending about a fastener that extends through said body between said obverse and reverse faces.

2. A load bearing panel as claimed in claim 1, wherein said first reinforcing and said second reinforcing are each sheet like -12- and whereby each sheet includes a plurality of apertures formed therein and whereby one of said apertures constitutes said engaging portion.

3. A load bearing panel as claimed in claim 2, wherein said first reinforcing and said second reinforcing each consist of a mesh like structure and said engaging portion includes a loop like reinforcing member that is attached to said mesh like structure. DATED THIS twenty-first DAY OF May, 2001 ONECRETE PTY LTD By its Patent Attorneys AHEARN FOX