Patent Publication Number: US-2007107345-A1

Title: Building panel

Description:
RELATED APPLICATIONS  
      The present application claims convention priority under 35 USC §119 to Australian Patent Application No. 2005905925 dated 26 Oct. 2005 and such application is hereby incorporated by reference.  
     FIELD OF THE INVENTION  
      The present invention relates to a building panel, and more particularly a building wall, ceiling or floor panel having at least a facing formed from a glass fibre reinforced cement.  
     DESCRIPTION OF THE PRIOR ART  
      It has been found that the building panels of this type of the prior art (which are not admitted as forming part of the common general knowledge) lack the desired degrees of strength and rigidity to withstand use in areas prone to high winds in particular.  
     SUMMARY OF THE INVENTION  
      In one embodiment of the present invention a building panel that overcomes or at least partially ameliorates some of the problems associated with the building panels of the prior art.  
      Usefulness of the present invention will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, one or more embodiments of the present invention is disclosed.  
      According to one or more embodiments of the present invention, although this should not be seen as limiting the invention in any way, there is provided a building panel including a face of fibre reinforced cement material, an integrally formed flange of fibre reinforced cement material extending from at least one side thereof, and a reinforcing member, at least a portion of which passes through the flange.  
      In one embodiment the panel is rectilinear in shape, having a pair of substantially parallel ends, and a pair of substantially parallel sides.  
      In one embodiment the panel is rectangular in shape.  
      In one embodiment there is a reinforced flange extending rearward of the face along each edge thereof.  
      In one embodiment the reinforcing member is made from steel.  
      In one embodiment a further integral reinforced flange runs between the substantially parallel ends.  
      In one embodiment a further integral reinforced flange runs between the substantially parallel sides.  
      In one embodiment the reinforcing member is a steel rod.  
      In an alternative embodiment, the reinforcing member is a steel channel.  
      In one embodiment there is a plurality of reinforcing members, which are fabricated so as to form a frame.  
      In one embodiment each of the integrally formed flanges abuts a further sheet of material that is then secured thereto so as enclose the back of the panel and define a cavity.  
      In one embodiment the further sheet of material is a plasterboard sheet.  
      In one embodiment the panel cavity can be filled with a heat and/or sound insulating material.  
      In a further form, an embodiment of the invention may be said to reside in a building panel including a supporting and reinforcing frame assembled from a plurality of frame members, each frame member having a full length outwardly extending flange extending from an edge thereof, a sheet of fibre reinforced cement material abutting a first side of the frames flanges, and a bead of fibre reinforced cement overlaying the frame members so as to form a flange through which the frame members pass.  
      In one embodiment the frame members are lengths of steel channel, each with a substantially constant U-shaped cross-section along its length that includes a base portion and a pair of outwardly extending flanges.  
      In one embodiment the frame members are arranged and welded to each other so that they define the perimeter edge of the panel, and the flanges of the perimeter forming members are directed inwardly.  
      In one embodiment a first flange of the steel channel abuts and is bonded to the sheet of fibre reinforced cement material.  
      In one embodiment there is at least a further length of channel running parallel to the direction of elongation of the panel so as to reinforce it.  
      In one embodiment there is at least a further bead of fibre reinforced cement applied to the back of the sheet of fibre reinforced cement, which runs transverse to the direction of elongation of the panel, so as to reinforce it.  
      In one embodiment a second flange of the steel channel abuts a further sheet of material that is then secured thereto so as enclose a cavity.  
      In one embodiment the further sheet of material is a plasterboard sheet.  
      In one embodiment the panel cavity can be filled with a heat and/or sound insulating material.  
      An alternative embodiment of the invention may reside in a building panel including a supporting and reinforcing frame assembled from a plurality of frame members, each frame member having a full length outwardly extending flange extending from an edge thereof, a sheet of fibre reinforced cement material abutting a first side of the frames flanges, and a bead of fibre reinforced cement overlaying the frame members so as to form a flange through which the frame members pass, and at least a further bead of fibre reinforced cement applied to the flange abutting side of the sheet of fibre reinforced cement, which runs between at least a pair of frame members so as to form a rib that is adapted to reinforce the panel.  
      An alternative embodiment of the invention may reside in a building panel having an outermost cladding comprised of at least a sheet of substantially fibre reinforced cement, and a support frame having at least a first frame member extending along a one side of the panel, and a second frame member extending along in a parallel alignment to the said first frame member an opposite side of the panel, the respective frame members being of an elongate shape with a constant cross sectional shape along at least most of the length of each frame member, each of the said frame members having a shape with a planar engaging face abutting an inner side of the cladding sheet and having the planar face provided by a portion of the frame member with a narrow edge along a one side of the frame member, the respective frame members being secured to the cladding by reason that at least one portion of the cladding being of a greater thickness than an immediately surrounding portion of the cladding extends to be interlocking with at least the edge of the frame member, and a further portion of the cladding having a portion that is of greater thickness than immediately surrounding portions and such further portion is positioned and shaped so as to extend as a stiffening rib from a one of the frames across to an opposite one of the frames.  
      In one embodiment the method includes the step of moulding the fibre reinforced cement around the reinforcing member or members.  
      In one embodiment the method includes the further steps of applying some of the fibre reinforced material to a mould, positioning the reinforcing member or frame, continuing with the application of the fibre reinforced material, allowing the fibre reinforced material to solidify, and then removing the building panel from the mould.  
      An alternative embodiment, the invention may reside in a method of building a wall panel including the steps of building a supporting frame from a plurality of frame members, each frame member having a full length outwardly extending flange extending from an edge thereof; abutting a sheet of moulded fibre reinforced cement material against a first side of the frames flanges; and applying a bead of fibre reinforced cement to a second side of the frame flanges so that the bead overlays the complete length of the flange thereby bonding the sheet of fibre reinforced cement material to the framework.  
      In one embodiment the fibre reinforced cement material is applied using a spray gun. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      For a better understanding of this invention it will now be described with respect to the exemplary embodiments which shall be described herein with the assistance of drawings wherein;  
       FIGS. 1 and 2  are front and rear perspective views respectively, of a building panel;  
       FIG. 3  is a back plan view of the panel in  FIG. 1 ;  
       FIGS. 4 and 5  are cross-sectional views through the panel in  FIG. 1 , at A-A;  
       FIG. 6  is a cross-sectional view through the panel in  FIG. 1 , at B-B;  
       FIGS. 7 and 8  are front and rear perspective views respectively, of a building panel according to an alternative embodiment;  
       FIG. 9  is a cross-sectional view through the panel in  FIG. 1 , at C-C;  
       FIG. 10  is a cross-sectional view through the panel in  FIG. 1 , at D-D;  
       FIG. 11  is a perspective view of a building panel according to yet a further form of the invention, illustrating the further sheet of material removed;  
       FIG. 13  is a perspective view of the building panel in  FIG. 11  showing a partial cross-section of the further sheet of material;  
       FIG. 14  is a detailed cross-sectional view through a portion of the building panel in  FIG. 11 ;  
       FIG. 15  is a partial cross-sectional view through a portion of the building panel in  FIG. 11 ;  
       FIG. 16  is a cross-sectional view through a variation of the panel in  FIG. 1 ; and  
       FIG. 17  is a cross-sectional view through a pair of abutting panels of the type illustrated in  FIG. 15   
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to  FIGS. 1 through 6 , where there is illustrated a rectangular building panel  1 . In this embodiment, the panel is of 2700 mm height, 1200 mm width, and 100 mm thickness, although the panels can be produced to size as required.  
      The building panel  1  is made from fibre reinforced cement material, it has a front face  2  and a rear face  4 . The panel includes an integrally formed flange  6  which projects from the rear face  4  of the panel, and which extends along the full length of each of the panels edges.  
      A 6 mm diameter steel rod reinforcing member  8  passes through the integrally formed flange  6 , stiffening and strengthening the panel  1 . This can be seen most clearly in  FIG. 5 .  
      The panel has a pair of substantially parallel ends  10 , and a pair of substantially parallel sides  12 .  
      A further integral flange  14  extends from the rear face  4 , and runs across the panel between the substantially parallel ends  10 , passing through the centre of the panel.  
      Yet a further flange  16  extends from the rear face  4 , and runs between the substantially parallel sides  12 , passing through the centre of the panel. These two additional flanges provide the panel with additional strength and stiffness, and can be seen most clearly in  FIG. 2 . These two additional flanges can be reinforced using steel rod if required.  
      Extra fibre reinforced cement material is applied in each of the internal corners formed between the flanges on the back of the panel  1 , so as to form in each internal corner a wedge  13  that gets progressively thicker as it approaches the rear face  4  of the panel. These wedges  13  eliminate stress risers that would otherwise be created by these internal corners when the panel is under load. In addition to this, these wedges provide additional material and therefore strength in these corners.  
      The edges defined by the flanges  6  along each of the sides and ends are substantially perpendicular to the front face  2  of the panel. This permits a pair of panels to be positioned adjacent to one another with abutting edges.  
      One method of forming a building a panel  1  in accordance with the present invention is now described.  
      First, a building panel mould is constructed so as to define the shape of the back face  4  of the panel. The mould is constructed so that each of the mould&#39;s wall members is detachably secured to the other wall members, and these wall members are then removably secured to the mould defining the back of the panel.  
      A layer of bond breaker is applied to the mould using a spray gun.  
      A mixture of concrete is then mixed in a concrete mixer using cement, sand and water in one embodiment according to the following proportions:  
                                                          Off white cement:   40   kg           Dried foundry sand:   43   kg           Water:   15   litres           Optipozz   4   kg           Polymer   5   litres                             Plasticizer/retardant   To suit           Antifoam   To suit                      
 
      This slurry is then pumped from the mixer to a spray gun.  
      A substantially continuous strand of alkali resistant (Zarcon coated) glass fibre is run to the spray gun, which is a concentric chopper spray gun, where it is chopped into 32 mm lengths and added to the slurry.  
      The slurry is then sprayed onto the mould so as to fill the cavities defining the flanges  6 ,  14  and  16 , until a desired depth is reached, at which point spraying is paused while the reinforcing rod  6  is positioned in the mould. Spraying then resumes until the mould has been filled.  
      Before the slurry has cured, it is compacted using a roller so as to create the front face  2  of the panel.  
      Once the slurry has cured, the panel  1  can be removed from the mould.  
      Referring now to  FIGS. 7 through 10 , where the steel reinforcement members in this case are u-shaped channels  20 . Each of these steel reinforcement members is a channel with a substantially constant U-shaped cross-section along its length, which includes a base portion A and a pair of outwardly extending flanges B extending from the edges of the base portion.  
      These channels  20  are arranged and then welded to each other so that they form a rectangular frame  22 , which defines the perimeter edge of the panel, and the flanges B of these perimeter-forming members are directed inwardly. A further channel  24  passes between the ends of the panel, passing through the centre of the panel. This frame  22  is moulded into the fibre reinforced cement material in the same fashion as the steel rod, as discussed above,  
      Referring now to  FIG. 11 , where the building panel  100  is rectangular in shape and the frame members are again arranged and welded to each other so that four of them define the perimeter edge of the panel, and the flanges B of these perimeter-forming members are directed inwardly.  
      There are four vertical frame members, or studs  106 , which are substantially equi-spaced and running parallel to each other along the length of the panel; the two edge forming studs, and two reinforcing studs. There is a horizontal frame member  108 , or noggin, at each end of the frame. The flanges  108 B of these noggins  108  overlap the flanges  106 A on the studs  106 .  
      A sheet of fibre reinforced cement material  110  is moulded to size so that its height and width match the dimensions of the perimeter of the frame  102 . This sheet of fibre reinforced cement material  110  abuts a first side of the frames flanges, and a bead of fibre reinforced cement  112  then overlays the complete length of a second side of the frame flanges, bonding the sheet of fibre reinforced cement material to the framework  102 .  
      There is a further, reinforcing bead  114  of fibre reinforced cement applied to the flange abutting side of the sheet of fibre reinforced cement. This reinforcing bead  114  is much deeper than the beads that bond the sheet of fibre reinforced cement material to the frame, and it runs from a first edge-forming stud, between all four studs, and right across the panel to the other edge-forming stud, forming a rib that stiffens and reinforces the panel.  
      A further sheet of plasterboard material  120  is cut to size so that its height and width match the dimensions of the perimeter of the frame  102  also. This sheet of plasterboard then abuts the flanges on the other side of the frame, and can be fixed to these using appropriate fasteners or adhesives so as to enclose a cavity in the panel. A 10 mm thick plasterboard such as that identified by the Trade Mark ‘Gyprock’, has been found to be ideal for this purpose.  
      The cavity defined by the panel can then be filled with a heat and/or sound insulating material  122 . Polyurethane insulation 1:1 or PIR 2:1 of 50 mm thickness has been found to be ideal for this purpose.  
      One method of forming a building panel in accordance with this embodiment of the present invention is now described.  
      First, a building panel mould is constructed so as to define the desired panel shape. The mould is constructed so that each of the mould&#39;s wall members is detachably secured to the other wall members, and these wall members are then removably secured to a smooth, flat sheet.  
      A layer of bond breaker is applied to the smooth, flat sheet and to the mould walls themselves, using a spray gun.  
      The support fame, as described above, is constructed from cold rolled steel channel. A mixture of concrete is then mixed in a concrete mixer using cement, sand and water in much the same proportions as those discussed above.  
      This slurry is then pumped from the mixer to a spray gun.  
      A substantially continuous strand of alkali resistant (Zarcon coated) glass fibre is run to the spray gun, which is a concentric chopper spray gun, where it is chopped into 32 mm lengths and added to the slurry.  
      A first layer of the slurry is then sprayed on the smooth sheet defined by the mould walls. Although the thickness of the first layer may be varied, it has been found that a satisfactory thickness for most structural applications is 15 mm. It would be understood that the thickness of the slurry could be increased to increase the strength of the panel.  
      After this first layer has been laid, and before the layer has cured, it is compacted using a roller so as to ensure that the slurry has a substantially uniform thickness.  
      The frame is placed within the mould so that the frame&#39;s flanges abut the slurry. Before the first layer of slurry has cured, a second layer is overlayed along at least a portion of the length of the flange abutting the slurry, but preferably it is applied so as to completely overlay the flange along a complete length of the frame&#39;s flange. This bead of overlay should be almost as thick as the first layer of slurry, which is 15 mm in this instance.  
      A build-up of the slurry is then sprayed between the studs about halfway along the panel so as to create a reinforcing rib. A reinforcing rib of 60 mm in depth and 100 mm in width has been found to significantly improve the strength and stiffness of a panel.  
      After the second layer of slurry has been applied so as create the flange bead and reinforcing rib, the panel is allowed to cure in the mould for a period of approximately twelve hours. The panel is then removed from the mould, and allowed to cure for a period of up to seven days; during this time, the panel is kept moist by intermittently spraying it with water.  
      Once cured, the panels can be secured to building framework using fasteners such as bolts and rivets that secure the panels through the noggins. Adjacent wall panels may be secured to each other by means of fasteners extending through abutting studs. A layer of caulking compound can be applied between adjacent wall panels to seal the joints and provide a smooth finish.  
      Referring now to  FIGS. 15 and 16 , there is a panel  200  similar to that in  FIGS. 1 through 10 , this panel differing in that it includes a recess  202  along the edges extending in the direction of elongation of the panel. When two of these panels  200  are positioned with these edges abutting, as shown in  FIG. 16 , the recesses co-operate to create a pocket  204 , through which a hold down rod  206  can be passed. In a typical installation, these hold down rods  206  are fixed into the concrete or timber floor, and they pass between the panels  200  in the pocket  204  and into the edge beam or top plate. These hold down rods  206  counteract shearing forces created by very high winds, and assist to hold down the roof frame in said high winds.  
      It is considered then that the panel according to the present invention will be of particular use top those wishing to build using a prefabricated panel of improved strength and rigidity.  
      Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures can be made within the scope of the invention, which is not to be limited to the details described herein but it is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus.