AU2016295418B2

AU2016295418B2 - Building panel having insert

Info

Publication number: AU2016295418B2
Application number: AU2016295418A
Authority: AU
Inventors: Timothy Mark GRABHAM
Original assignee: CSR Building Products Ltd
Current assignee: CSR Building Products Ltd
Priority date: 2015-07-17
Filing date: 2016-07-15
Publication date: 2021-11-18
Anticipated expiration: 2036-07-15
Also published as: WO2017011858A1; AU2016295418A1

Abstract

A lightweight building panel made from autoclaved aerated concrete has a lifting element in the form of an insert partially embedded within the panel and having at least one exposed end extending from an access void provided in at least one surface of the building panel to allow lifting of the panel by a lifting apparatus connectable to the lifting element. The lifting element can take a variety of forms and be located at different locations within the panel. The access void provides clearance enabling access to the end of the lifting element for releasable attachment of the lifting apparatus to the panel. The advantage of having an integral lifting element is that multiple building panels can be lifted in unison and, if required, deposited one at a time in sequence where required for installation in a building in a single lift operation.

Description

BUILDING PANEL HAVING INSERT

FIELD

The present invention relates generally to building panels.

In one form, the present invention relates to lightweight building panels made from 5 autoclaved aerated concrete (AAC) and to methods of their manufacture.

In one form, the present invention relates to AAC panels having integral lifting elements for use in lifting the panel into place on a building construction, particularly lifting multiple panels simultaneously for installation in multi-storied buildings and to methods of forming the panels with the integrated lifting elements.

10 The present invention finds particular application as a lightweight AAC building panel that can be lifted together with other similar lightweight AAC building panels simultaneously using the respective integral lifting elements provided in or on each panel.

Although the panel will be described with reference to one or other embodiments of the i s panel, it is to be noted that the scope of protection is not restricted to the described embodiment or embodiments but rather protection is more extensive so as to include other forms and arrangements of the panel and of the lifting element, and uses of the panel and/or lifting elements other than specifically described.

BACKGROUND

20 During construction of buildings, particularly multi-story buildings, there is a need to lift building panels used in the construction of the building from ground level to locations where the building panels are to be installed in the building, including lifting the panels to upper levels of the building well above ground level.

In the past, it has been necessary to lift a single panel only at any one time so that the 25 panel could be placed at a specified final location within the building as required. It was only after the panel had been installed at the final desired location that the lifting apparatus was free to return to ground level and another single panel lifted into place for installation at the new desired final location, typically close to the previously lifted and installed panel. Thus, it was usual to lift a single panel only during a lift. However, lifting individual panels one at a time is time consuming and hence costly, adding to the overall cost of construction of the building. Accordingly, there is a need to reduce construction costs by being able to lift more than a single panel at a time in order to speed up construction time.

5

However, previous attempts to lift more than a single panel at the same time in groups of panels have not been entirely successful for one reason or another due to difficulties in controlling the movement of the group of panels or the movement of individual panels of the group, difficulties in connecting the panels to each other allowing for 10 separate placement of the individual panels one at a time at the respective final

locations as desired, lifting the weight of a group of panels simultaneously and complying with the relevant provisions of the rules and regulations concerning lifting building panels at construction sites, including satisfying Occupational Health and Safety requirements, particularly relating to lifting operations. i s More particularly, previous attempts at lifting multiple panels simultaneously have not allowed separate placement of one panel at a time or one group of panels at a time at different respective final locations for the individual panels or group of panels, depending upon where the panels were required for installation but rather all of the multiple panels required unloading at the same intermediate location due to the

20 equipment and method used for individually lifting the panels.

Once the individual panels were unloaded as a group at the one intermediate location, the panels needed to be repositioned manually by workers stationed in close proximity to the multiple panels, such as for example, at an upper level of the building being constructed. Whilst the use of such equipment and methods saved some time in 25 actually lifting the panels, extra time and workmen were needed to manually reposition the panels once deposited at the intermediate location of the upper level so that there was little cost savings in overall construction costs because there was only a slight improvement in the time taken to position the individual panels at their respective final locations.

30 Other attempts at lifting multiple panels simultaneously included tethering individual panels to each other in sequence, so that a plurality of panels were interconnected by tethers, such as flexible tethers, including straps, chains or similar. While the use of such systems allowed the placement of single panels individually one at a time at different locations by operators being able to disconnect the panels from each other in sequence as required, there were major safety concerns over lifting multiple panels in an unrestrained interconnected series or sequence in which the individual panels were 5 able to move more or less independently of one another, even when interconnected to each other since in adverse weather conditions, due to the panels being somewhat unrestrained, there could be unwanted movement of one or more of the panels, sometimes dangerously so, such as for example, unacceptably large relative movements of one panel with respect to another panel of the sequence of panels in

10 windy conditions as the panels swayed from side to side while being lifted into place.

In some circumstances, there was a sufficiently large range or amplitude of movement of the panels to strike or collide with each other or with parts of the building undergoing construction, or with parts of the lifting apparatus, having the potential for damage and injury, since there was little or no control of movement of the respective panels, i s particularly the lower panels in the series or sequence when actually being lifted into place by the lifting apparatus, even if guy ropes, wires or stays were used to constrain movement of the individual panels in the interconnected sequence.

Furthermore, in configurations where individual panels were flexibly tethered to one another, only two or three individual panels at most, could be lifted in the one lift owing

20 to overall distance occupied by the panels from the upper level to the lower level due to the required separation of the panels from each other, including the distance apart of the individual panels from each other, by the alternating arrangement of flexible tethers and panels forming the sequence of panels being lifted in unison, which made lifting more than, say, three panels simultaneously, unwieldy and/or dangerous because of

25 the distance extending between the lower edge of the lowermost panel and the upper edge of the uppermost panel and from the lifting apparatus.

Therefore, there is a need for a panel which can be lifted as part of a group of panels in a single lift of the lifting apparatus and individually placed at a desired location as a single panel or set of panels.

30 It is to be noted that not all embodiments of the panel and/or of the lifting element will overcome all deficiencies of current techniques for lifting building panels. One embodiment may overcome one deficiency, whereas another embodiment may overcome a different deficiency. Some embodiments may overcome two or more deficiencies. SUMMARY

According to one form of the present invention, there is provided a building panel comprising a body portion generally in the shape of the building panel, the building 5 panel having at least a first surface, the first surface being associated with at least a first lifting element for use in lifting the building panel, the lifting element having a first part for secure attachment of the lifting element to the body of the building panel in the region of the first surface to fixedly locate the lifting element with respect to the panel to facilitate lifting of the panel, the lifting element having a second part accessible from

10 outside of the first surface of the building panel for cooperation with an external lifting device to lift the panel using the lifting device, wherein the second part of the at least first lifting element is provided with an engager for selective cooperative engagement with the lifting device such that when the lifting device is connected to the engager of the first lifting element, the panel moves in response to corresponding movement of the i s lifting device to move the panel.

According to one form of the present invention, there is provided a method of making a building panel having at least one lifting element, the panel having a body portion generally in the shape of the panel, and the body portion having at least a first surface associated with the lifting element, the method comprising the steps of providing a

20 mold generally for forming the shape of the body of the panel, locating the lifting

element at a predetermined location and at a preselected orientation within the mould, the lifting element having a first part and a second part, securing the lifting element within the mold to maintain the predetermined position and orientation of the lifting element during formation of the panel, forming the body of the panel generally in

25 accordance with the shape of the mold, wherein the position and orientation of the first lifting element is such that the first part of the lifting element is secured to the body and the second part of the lifting element is accessible from outside the first surface of the body, the second part of the lifting element provided with an engager for selective cooperative engagement with a lifting device to facilitate lifting of the panel.

30 BRIEF DESCRIPTION OF EMBODIMENTS

In one form, the building panel is a lightweight building panel, in the form of a slab, block, or other generally rectangular prism or cuboid shape, such as a substantially cuboid building panel having two opposed faces, being an obverse face and a reverse face, two opposed longitudinal sides in spaced apart relationship to each other, one on either side of the panel, and two opposed transverse sides or ends in spaced apart relationship to each other, one on either end of the panel, in which the length of the 5 longitudinal sides is greater, preferably considerably greater, than the length of the transverse sides or ends, wherein in forms of the panel all of the longitudinal sides and transverse ends extend substantially perpendicularly between the two opposed faces. However, shapes other than rectangular prisms are possible.

More typically, the building panel is a parallelepiped lightweight building panel. Even 10 more typically, the building panel is a lightweight slab building panel, typically an

autoclaved aerated concrete panel (AAC panel). Preferably, the lightweight building panel is an AAC panel supplied, manufactured and/or available from CSR Building Products Limited, under the name "Hebel®, including panels marketed under the following names, "Hebel® powerpanel", "Hebel® power floor", "Hebel® solid panel", i s "Hebel® power floor+", "Hebel® commercial floor", "Hebel® Smartslab", "Hebel®

Powershield" or similar.

Forms of the panel typically have a longitudinal or lengthwise extending axis extending in a direction corresponding to the long sides of the panel, and a transverse axis extending in a direction corresponding to the short sides or ends of the panel. The 20 longitudinal axis and transverse axis intersect at the midpoint of the panel.

The rectangular building panels can be arranged to form a floor or a wall of a building, including a single story building or a multi-story building requiring the panels to be lifted into place for installation on or in the building during construction of the building.

In one form, the individual panels have smooth faces or are smooth sided and/or are 25 smooth edged, whereas in another form, the faces of the panel are smooth but the edges or sides of the panels are provided with a surface discontinuity or irregularity, or in another form, both the faces of the panels and the edges or sides of the panels are provided with surface discontinuities or irregularities. Typically, the surface

discontinuities and/or irregularities on the faces of the panel are different from the 30 surface discontinuities and/or irregularities on the sides or edges.

In one form, the faces of the panels are provided with surface decorations, such as for example, to enhance the visual appeal of the panels when forming the walls of the building or to produce "architectural effects" of the building. In one form, the surface decoration includes troughs or depressions, such as for example, formed by routing or similar treatment of the face or faces of the panel. In one form, the internal and external surfaces of the building panels and/or of the building in which the panels are 5 installed can have a surface treatment, such as for example, be suitably finished to improve the external and/or internal appearance and/or durability of the panels or to enhance one or more properties of the panel or of the building, including the visual appeal of the panel and/or building. One suitable finish of the panels is that the panels are coated or rendered or the like by a suitable coating or surface treatment, to 10 increase the integrity of the building to protect the panel and/or building, including

improving the strength of the building or to enhance the visual appeal of the building. In one form, the coating applied to the panel is an acrylic protective coating to increase the durability of the panel.

Typically, in one form, the panels are provided with a surface discontinuity or i s irregularity provided in or along one or more of the sides or edges of the panels. One form of the discontinuity or irregularity is a mating or engagement element located on one or more of the side edges, preferably on or along the longitudinal side edges or on or along the transverse side edges of the panel or on both the longitudinal and transverse side edges of the panel, typically in the form of cooperative engaging or 20 cooperative mating elements. In some forms of the panel, the transverse or short edges or sides are substantially straight and smooth or in other forms the transverse or short sides have cooperative mating elements.

In one form, the cooperative engaging or mating elements are in the form of a depression, rebate, groove, trough, concavity, channel, cavity, chamber, bore, shaft or

25 similar void or depression. Typically, in another form, the cooperative engaging or mating element is in the form of a surface discontinuity or irregularity in the form of a projection, crest, shaft, rod, tie, protrusion, tongue, boss, convex extension or other outwardly projecting or extending protrusion or extension. Typically, the cooperative engaging or mating elements are a complementary tongue and groove arrangement in

30 which the tongue of one panel is received in the groove of an adjoining panel to

interlockingly connect the panels to one another.

In one form, the outwardly extending projection and the inwardly directed depression are complementary to one another so as to be matched to each other for mating engagement and/or cooperative engagement with each other by the projection being received within the depression to interconnect and/or locate the two panels with respect to each other. Preferably, the two adjoining panels are centrally located precisely one about the other to form a vertical wall having a substantially constant 5 thickness or a horizontal floor having a constant thickness.

More typically, the projection provided on the relatively lower building panel of the two abutting building panels located one above the other is directed upwards in a substantially vertical direction, and is typically received in the downwardly directed groove or similar depression of the relatively upper building panel to join the two panels 10 together.

In one form, the transverse edges or sides of the panel are smooth, flat, or otherwise free of surface irregularity or discontinuity, i.e. are free of mating or engaging elements.

In one form, the panel is provided with one or more rebates, channels or grooves. Typically, there are two rebates, channels or grooves, one on either side of the panel, i s typically, on each of the long sides, more typically on, at or towards the upper corner or edges of both long sides.

In one form, the building panel is provided with two rebates, preferably one rebate being located along one side or edge and another rebate being located along another side or edge, more preferably on opposed sides or edges, such as on the two 20 longitudinal edges or along the two longitudinal corners of one face of the panel, more preferably the upper face in use of the panels.

In one form, the two opposed rebates have the same shape, profile, cross-section or similar, whereas in other forms, the opposed rebates have different shapes, profiles, cross-sections or similar.

25 In one form, the building panel is optionally provided with a rebate along one or both of the transverse edges or sides of the building panels either as a substitute for the rebates along the longitudinal sides, edges, or corners or in additional to the longitudinally extending rebates.

The rebates can have any suitable shape or profile or be of any suitable or required 30 style and size. In one form, the rebate has two parts, an upper part and a lower part. Typically, the width of the upper part, closer to the top face of the panel is smaller than the width of the lower part which is closer to the bottom face of the panel. More typically, the upper and lower parts are angularly inclined to one another. Typically, the upper and lower 5 parts are angularly inclined to each other in opposite directions to form a waistline immediate the two parts, typically at the junction of the two parts. More typically, the upper part is inclined at an angle of between about 100° and about 135° to the top face and the lower part is inclined at an angle between about 10° and 45° to a plane parallel to the upper face. However, the parts of the rebate can have any suitable inclination to 10 one another and to the faces or edges of the panels. However, parts or profiles of the rebate can have any suitable inclination.

In one form, the rebate has a generally semicircular or half round shape or profile when viewed in cross-section. Typically, this form of rebate is located in one longitudinal side closer to the obverse face of the panel i.e. the upper or outer face in use. i s One form of the panel has a single lifting element whereas other forms of the panel have two or more lifting elements, typically multiple lifting elements. If there are two or more lifting elements, the elements are typically located in spaced apart relationship to one another. More typically, the lifting elements are located at symmetrical locations within the panel, even more typically symmetrically about the midpoint or midplane of

20 the panel, preferably about the transverse midplane of the panel located towards the transverse sides or ends of the panel. More typically, the lifting elements are in spaced apart substantially parallel relationship to each other.

In one form, the lifting elements of one building panel are located at the same location as the lifting elements of another building panel so that when both building panels are

25 arranged in stacked relationship one upon the other, the lifting elements at the same location are aligned with each other to enable the two panels to be lifted

simultaneously using the lifting tool or lifting device. Typically, the panels are manufactured with the location of the lifting elements being constant, all of the panels can be lifted simultaneously using the same lifting tool or device by the lifting elements

30 always being in alignment with each other or being nearly so for cooperative

engagement with the lifting tool or device.

Forms of the lifting element include a single elongate lifting insert or similar which extends transversely from one side or edge of the panel to the opposite side of the panel through the entire width of the panel. Other forms of the lifting element include two or more segments or sections which are placed in effect to combine to form the lifting element in which one section is located at or towards one side of the panel, typically one of the longitudinal sides or edges of the panel, and the other section is 5 located at or towards the opposite longitudinal side or edge of the panel so that one section extends from and is accessible at one side of the panel and the other section extends from and is accessible at the other side of the panel. In one form, the two sections on either side of the panel are in alignment with each other, such as for example, being collinear, whereas in other forms, the two sections are off-set from 10 each other by being spaced laterally from each other or being staggered longitudinally of each other. In one form, the inserts extend from alternating sides of the panel in sequence in staggered spaced apart relationship.

Forms of the lifting element extend outwardly from the respective longitudinal edge or side, typically so as to be accessible from outside the panel by being located in a void, i s typically an access void, or similar provided at the side or edge of the panel, such as for example, formed in the side or edge of the panel. The second section of the same lifting element or the two sections of the lifting elements have exposed ends at the respective sides of the panel, typically located in access voids formed or molded in the sides or edges of the panels. The voids can be formed during or after manufacture of

20 the panel and/or after the panel has been cut to the required shape or size.

Forms of the lifting element in the form of an insert are metal rods, bars, channels, grooved sections, typically channel sections having a U-shaped profile, a C-shaped profile or the like including having a web section located between two spaced apart side walls or flanges extending from the web section at either side of the insert, 25 typically extending substantially perpendicularly from the web section. The insert can have any suitable or convenient profile or cross-section including being symmetrical or asymmetrical about the centreline of the insert.

In one form, the lifting element or insert has two end sections or two outer sections, or two exposed sections which sections are exposed at either end, and a central or inner 30 or midsection which is located internally within the panel, such as for example, by being embedded within the panel. In other forms, the insert has a single exposed outer end and a single inner end embedded within the panel.

In one form, the central section or portion, or inboard end or portion, is located within the body of the panel, typically embedded within the material from which the panel is made, such as embedded or enclosed within the AAC mixture from which the panel is made. The outer end or end portions or sections of the lifting elements are exposed by being located within the access voids to extend outwardly from the access voids in the 5 sides of the panels.

In forms of the panels, the inserts or lifting elements are arranged in alignment with the access voids, which in one form are cut-outs, rebates, cavities, spaces, gaps, concavities, or similar. The access void can have any suitable or convenient shape for allowing attachment of the lifting device of the exposed end of the insert and/or release 10 of the lifting device from the exposed end of the insert, including having sufficient

clearance around the exposed end of the insert to engage more than a single exposed end of respective inserts, in the event that the panels, when in a stacked array, are not perfectly in alignment with each other so that the position of the exposed ends of the inserts are located slightly offset from each other. i s Forms of the accessible ends of the exposed ends of the lifting element are provided with an engager for engaging a suitable lifting device, such as for example, a lifting bracket, a lifting arm, a lifting leg, a lifting tool, a lifting assembly having a fixed part and a movable part for selectively engaging the engager or the like. Forms of the engager which are selectively cooperatively engageable with the lifting device include

20 an end profile for facilitating engagement of the insert with the lifting device. One form of the end profile is tapered, bevelled, inclined, sloping or the like to allow clearance between the tool and the insert to connect the tool to the insert, and/or to assist in manufacture of the panel. However, other forms of the end of the insert are straight. In one form, the end of the insert is straight or perpendicular to the lengthwise

25 extending axis of the insert in order to assist in alignment of the lifting device with the exposed ends of the inserts collectively of the stacked array of panels, and

engagement/disengagement of the lifting device from the insert and/or engager provided at the end of the insert.

In one form, the engager is an aperture, opening, hole, bore, perforation, cavity, void, 30 or similar. In one form, the engager is a projection including a pin, peg, boss, spigot, rod, tube, stub, or the like. However, the engager can have any suitable shape, profile, type, configuration or the like for cooperative engagement with the tool, such as for example, a lug having a single aperture. In one form, the lifting element is typically in the form of a channel section having a central web located between two side walls, typically in the form of a flange. Forms of the insert are provided with one or more retainers for assisting in retaining the channel section embedded within the AAC mixture typically, during and after manufacture of 5 the panel. In one form, the retainers provided on the lifting elements cooperatively engage with the reinforcement incorporated within the shaped body of the panel.

Typically, the reinforcement is a mesh, such as a reinforcing mesh, typically in the form of a single sheet or in the form of a cage having two or more sheets interconnectingly joined together, such as for example by spacers. More typically, the mesh or cage is 10 composed of rods, bars, tubes, or the like, preferably round rods, circular rods, or the like arranged in an interconnected array or grid-like pattern or arrangement. In one form, the retainers extend at least partially out of the plane of the lifting element, typically by being stamped from the web portion or wall portion of the channel section.

In one form, the retainer is a projection, protrusion or other fitting extending outwardly i s from the insert. Forms of the retainer include a metal hook, fastener, clamp, clip, barb, tongue, cleat, spike, tooth or the like having a shank portion and a tip portion. Forms of the shank portion can be straight or curved, typically an outward curve, an "S" shaped compound curve, or be divergent or convergent with the body of the channel section. Typically, the shank is in the form of a single segment, or two or more 20 segments which may be inclined to each other. Typically, the hook is movable, and the tip portion is able to be deflected, typically being resiliently deflectable, or deformable so as to move slightly to pass over a circular rod of the reinforcing mesh and to resiliently spring back into place when the tip of the hook clears the circular rod of the mesh in order to retain the rod closer to the root of the hook, clip or similar in the 25 space between the web or wall of the insert and the shank of the hook.

Forms of the lifting element are positioned at a predetermined location within the mold or similar for forming the panel. In one form, the lifting element is located at or towards one or other or both transverse ends. Forms of the lifting element are oriented to extend substantially transversely through the width of the panel. However, in other 30 forms of the panel, the lifting element extends substantially longitudinally or

substantially obliquely from one end of the panel to the other end of the panel, or from one side of the panel to the other side of the panel, or to extend from both sides or both ends of the panel, or from one end and one side of the panel. In one form, the orientation of the lifting element is such that the channel section of the insert extends substantially parallel to the side walls of the mold which in one form of the mold is substantially vertical.

In one form, the individual members or rods of the mesh assist in retaining the channel 5 section in the correct orientation prior to and/or during manufacture of the panel.

Typically, the individual rods or bars of the mesh cooperatively engage with retainers provided on the lifting element to assist in locating and positioning the lifting element in the correct location and orientation. In one form the reinforcement is in the form of a cage or similar made from two layers of mesh interconnected together.

10 Forms of the lifting element have two, three, four or more retainers located in spaced apart relationship to one another in the longitudinal direction of the elongate lifting element. In one form, the spacing of the retainers corresponds to the spacing of the rods or bars of the reinforcement mesh or the like, including the spacing of the rods or bars being regular or irregular, such as when pairs of lengthwise extending rods have a i s first spacing within each pair and a second spacing between adjacent pairs of rods.

BRIEF DESCRIPTION OF DRAWINGS

Forms of the building panel and the lifting element will now be described to illustrate embodiments of the panel and their methods of manufacture with reference to the accompanying drawings in which:

20 Figure 1 is a perspective view of one form of the building panel having one form of the lifting element embedded therein.

Figure 2 is an enlarged view of circle A of Figure 1 showing the relationship between the exposed end of the lifting element and the corresponding access void.

Figure 3a is a top plan view of the building panel of Figure 1 showing one form of the 25 lifting element in dotted outline.

Figure 3b is a top plan view of another form of the building panel showing another form of the lifting element in dotted outline.

Figures 4a and 4b are side elevation views of opposite longitudinal sides of the panel of Figure 1 showing the different profiles of the two rebates extending lengthwise the

30 panel. Figures 5a and 5b are end elevation views of either end of the panel of Figure 1 showing the profiles of either longitudinal side of the panel.

Figure 6 is a perspective view of one form of the lifting element in the form of a channel section having four spaced apart retainers.

5 Figure 7 is a top plan view of the panel of Figure 1 showing one form of the mesh

reinforcement in phantom and two different forms of the lifting element embedded within the panel.

Figure 8 is a side elevation view of the panel of Figure 1 showing the mesh in phantom embedded within the panel and the exposed ends of the two forms of the lifting 10 element.

Figure 9 is an enlarged view of circle B of Figure 8.

Figure 10 is an end view of the panel of Figure 1 showing the mesh reinforcement in phantom.

Figure 1 1 is an enlarged view of circle C of Figure 10 showing the engagement of one i s of the hooks of the lifting element with one of the rods of the reinforcement mesh.

Figures 12a, 12b and 12c are side views of one form of the retainer of the lifting element in the process of engaging with a rod of the reinforcement mesh to secure the lifting element to the mesh when in the mold.

Figure 13 is a perspective view of part of the mold showing a pair of spaced apart 20 lower formers for receiving the lifting elements.

Figure 14 is a partial perspective view of the mold showing a pair of spaced apart upper formers being located in place to retain the multitude of lifting elements in place in the mold with the lifting elements extending from respective lower formers.

Figure 15 is a partial cross-section through one form of the lower former.

25 Figure 16 is a partial cross-section through one form of the upper former.

Figure 17 is a perspective view of the mold ready to receive a mixture for forming the panel of Figure 1 . Figure 18 is a perspective view of four panels of Figure 1 in stacked abutting relationship one upon the other showing the exposed ends of the lifting elements of the respective panels in more or less vertical alignment with each other.

Figure 19 is a perspective view of another form of the upper former for forming the 5 access voids within which the exposed ends of the lifting elements are located.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

One embodiment of a building panel, in the form of a light weight flooring panel will now be described in detail. It is to be noted that the panel can have other forms, including other shapes, such as for example, in the shape of a trapezoidal prism. A 10 lightweight flooring panel, generally denoted as 10 is typically made from a lightweight structural building material, such as autoclaved aerated concrete (AAC) of the type made by CSR Building Products Limited and available under the name of Hebel®, including variations thereof.

Although the panel will be described by reference to a flooring panel, other forms of the i s panel can be used as wall panels, particularly as interior or exterior wall cladding in multi-storied buildings.

Panel 10 is of a solid generally rectangular prism shape, such as a general

parallelepiped shape or similar having a top or obverse face 12, a bottom or reverse face 14, two longitudinal sides 16, 18 and two transverse ends 20, 22 generally

20 arranged to extend perpendicularly to one another to form a generally rectangular prism shaped slab or similar shape having a length of typically up to about 6 meters, a width of typically up to about 600mm and a thickness of typically up to about 300mm or more. However, panel 10 can be made in any suitable length, width or thickness combination as required depending upon the type of use required and the construction

25 method of the building using the panels, such as whether panel 10 is used as flooring with obverse face 12 facing upwards or as wall cladding with observe face 12 facing outwards.

A discontinuity in the form of a rebate, such as a groove or similar is provided along the upper side edge of panel 10 on both sides of panel 10. The discontinuity can take any 30 suitable or convenient form. One preferred form of the rebate is a double profile (DP) groove, notch, or similar 24, extending lengthwise along one of the upper longitudinal side edges or corners of obverse face 12 in use of panel 10, as shown more particularly in Figures 1 , 5a, 5b and 18. In one form, groove 24 is formed from two surfaces angularly inclined to one another to form an angulated groove or groove having an inclined profile. It is to be noted that groove 24, 26 can take any suitable 5 profile, including being of the same general shape or of different shapes.

One form of groove 24 will now be described.

The two inclined surfaces forming groove 24, are an upper surface 28 which is straight sided, or is an undercut surface extending from top face 12 inboard of panel 10 at an angle, in a generally downwards direction away from top face 12, and a lower surface

10 30 which extends from the inboard lower edge of upper surface 28 to side surface 16 at a downwardly directed angle, also in a direction away from top surface 12. In one form, the junction between upper surface 28 and lower surface 30 is a waist line. In one form, the angle of inclination of upper surface 28 can vary from about 100° to about 135 ° with respect to obverse face 12, and the angle of inclination of lower i s surface 30 with respect to a plane parallel to the plane of obverse face 12, can vary from about 10° to about 45°. Other inclinations are possible.

It is to be noted that groove 24 provides a longitudinal slot into which part of a ring anchor system can be located, such as for example, an elongate rod or bar to assist in securing panel 10 in place as part of the floor at one level in the multi-storied building.

20 Additionally, it is to be noted that groove 24 is shaped to receive elongate reinforcing bars, tie down bars or other fasteners therein to assist in fastening the flooring panels to the solid substrate of a floor to maintain the flooring panels in position after installation, such as for example, the reinforcing bars forming part of a "ring anchor system" which is anchored by steel cleats located external to the floor substrate or

25 steel framework members, to resist upward movement of the panels from the floor when installed in the building, also to be described in more detail later in this specification.

Another form of the rebate, located on the opposite side of panel 10, but close to the edge of obverse face 12, is a rebate 26 of a generally semi-circular or part round 30 profile. Rebates 24, 26 are shaped so as to cooperatively receive tie down rods or similar therein or therebetween to secure panel 10 within the building.

Panel 10 is provided with one or other form of a lifting element. One form of the lifting element is an insert 40 in the form of a U-shaped channel section having a central web 41 located between two walls 43, extending substantially perpendicularly from the web, typically in the form of flanges located at either side of web 41 .

In one form, insert 40 is a single elongate channel section extending from one long 5 side of panel 10 to the other long side, as shown more particularly in Figure 3a. In another form, the insert is in the form of two spaced apart segments 42, in alignment with each other, extending outwardly on opposite long sides of panel 10 as shown in Figure 3b. Although the insert can have different forms and be made from separate segments, the insert will be described as being a single elongate channel section 40 10 extending from one longitudinal side 16 of panel 10 to the other longitudinal side 18 of panel 10 for ease of expression and clarity of understanding.

Insert 40 has two exposed ends 44, extending outwardly from respective long sides 16, 18 of panel 10 so as to be accessible from outside of panel 10. Each end 44, is provided with an engager, typically in the form of an aperture 50 for cooperative i s engagement with a suitable lifting device to lift panel 10.

Panel 10 is provided with a pair of spaced apart access voids 52 on either long side 16, 18. Voids 52 allow access to ends 44 of insert 40 and to apertures 50 for lifting panel 10 such as for example, for the ends of a suitable lifting device to engage with aperture 50. The engager can be of any suitable form, configuration, shape or type.

20 Aperture 50 is preferably circular. However, other forms are possible such as being a slot, or square, rectangular, oval or the like. The distal ends 44 of insert 40 are tapered or bevelled having inclined outer edges in the walls of the U-section forming the insert as shown more particularly in Figures 2 and 6. The inclined edges assist in the manufacture of the panels by helping guide the ends of the insert into the formers

25 located at the bottom of the mold or along the base of the mold at spaced apart

locations.

Insert 40 is generally elongate of a size sufficient to span from one long side 16 of panel 10 to the other long side 18 of panel 10. The actual size of insert 40 is determined by the width of panel 10 so that the length of insert 40 substantially 30 corresponds with width of panel 10, and can range from less than about 150mm to more than 600mm. Insert 40 is provided with a multitude of spaced apart retainers in the form of hooks 46. Each hook 46 is provided with a shank 47 and a tip 48 in which tip 48 is spaced apart from web 41 of insert 40. Hook 46 can have any suitable form. In one form, shank 47 is generally arcuate (not shown) whereas in another form, shank 47 has angularly 5 inclined end and mid segments as shown more particularly in Figures 6, 12(a), 12(b), 12(c). Tip 48 at the distal end of shank 47, is bent or otherwise curved inwardly in the direction of web 41 of insert 40 so as to be able to capture and retain a part of the reinforcing mesh embedded with panel 10 as will be described in more detail below.

Void 52 can have any suitable or convenient shape. Void 52 is provided to allow 10 access to end 44 of insert 40 so that a cooperative part of the lifting device can

cooperatively engage with aperture 50 to securely connect the lifting device to panel 10.

Void 52 can be formed using a former placed strategically within the mold. One typical shape of the former is illustrated in the accompanying drawings, particularly Figures 15 i s and 16. The form of void 52 formed by the formers of Figures 15 and 16 has an

outboard tapered wall 54 located towards one transverse end, a central recessed straight wall 56, and an inboard tapered wall 58 located on the other side of the central wall 56, for defining the void.

One form of the former can be provided with internal cavities or hollowed sections, 20 typically to reduce the weight of the former, and to reduce the cost of the former by requiring less material. However, other forms of the former are solid, such as to have increased strength and rigidity depending upon requirements of the molding process, such as for example, the size of the panels being molded.

In one form, void 52 can provide clearance to allow selective access to end 44 of insert 25 40 at the side of panel 10, particularly to aperture 50 to allow cooperative engagement with a suitable lifting device, typically in the form of a lifting tool, lifting arm, lifting bracket, or the like having a movable grip or similar in the form of a pin, peg or other projection for being received within aperture 50, to enable a group of individual panels in stacked relationship one above the other, as shown more particularly in Figure 18, to 30 be lifted simultaneously in a single lift and unloaded separately at different respective locations by the lifting tool moving to a disengaged position for disengaging the movable grip, pin, peg or similar, of the lifting tool from the insert, most notably aperture 50, of the lowermost panel of the stack of panels to allow the lifting tool to be removed from the panel and reconnected to the next lowermost panel in the stack of panels to move the panels to the respective new locations.

One form of the upper former for use in molding access void 52 of panel 10 will now be described with reference to Figure 19. This form of the upper former includes a block 5 made from polystyrene or similar material in the shape and profile complementary to the shape and profile of access void 52, which voids are to be formed at spaced apart locations along the longitudinal side of panel 10. The polystyrene block is retained in position by a suitable subassembly. One form of the suitable subassembly for retaining the polystyrene blocks in place within the mold during formation of a block in

10 the form of a pre-form from which individual panels can be produced, is illustrated in Figure 19, which subassembly is in the form of a gantry, that can be raised and lowered to retain and release the polystyrene blocks in and from the mold as required. Gantry 86 includes upper framework 88 comprising a pair of longitudinally extending framework members 90a, 90b and a multitude of transversely extending framework i s members 92 interconnected together to form a lattice arrangement. A multitude of spaced apart hinged plates 94 downwardly depend from, or are suspended from, lower framework member 90b. Plates 90 are spaced apart corresponding to the spacing apart of where access voids 52 are to be formed during the molding process.

Plates 94 are located in register with the location of the polystyrene blocks. Plates 94 20 are provided with an outwardly extending projection 96 of a size and shape

corresponding to the size and shape of a receiver formed in the polystyrene block. In one form the receiver includes a slot, groove, recess, or similar having the same general shape and profile as the end 44 of insert 40, typically a U-shaped groove or slot within which the upper end of insert 40 is cooperatively received. The polystyrene 25 block has a further slot, typically extending transversely to the slot for receiving the end of the insert corresponding to the web section of the insert. The transverse part of the further slot is provided for engaging with outwardly extending projection 96 of plate 94.

When gantry 86 is in a lowered position, projection 96 is received within the further slot to hold the polystyrene block in position on the end of the insert with sufficient force to 30 resist displacement when the fluid AAC mixture is introduced into the mold. When the AAC block is in the green state of cure, gantry 86 is raised thereby withdrawing projection 86 from the further transverse slot to allow removal of the polystyrene block from the mold by lifting the polystyrene block of end 44 of insert 40. Void 52 is of a size, shape and profile to provide sufficient clearance for the lifting tool to be located within void 52 for the lifting tool to cooperatively engage with end 44 of insert 40. In particular, the width or side to side dimension of void 52 is sufficient to accommodate misalignment of individual panels from each other within the stack of 5 panels, so that ends 44 of insert 40 are not all perfectly aligned with each other but rather are laterally displaced from each other owing to the individual panels not being perfectly aligned but rather being placed generally on top of each other in approximate alignment. Additionally, the lifting tool is provided with sufficient tolerances in the part of the lifting tool co-operating with ends 44 of inserts 40, which part collectively 10 engages with ends 44 of insert 40 when panels 10 in stacked array, but slightly offset from each other, resulting in the inserts being slightly displaced laterally from each other, so as to be able to cooperatively engage with all inserts to lift the stacked array simultaneously.

Manufacture of panel 10 will now be described with particular reference to Figures 8 to i s 18.

In one form, a mold, generally denoted as 60, is provided within which a block can be molded from which a multitude of panels 10 can be produced. Mold 60 includes base 62, a first side wall 64, a second side wall 66, a first end wall 68, and a second end wall 70. It is to be noted the second side wall 66 and second end wall 70 are omitted

20 from Figures 13 and 14 for clarity. Mold 60 is not provided with a closed top or lid but rather is open. Typically, mold 60 is in the form of an open box having dimensions corresponding to the length and width of panels 10, but not corresponding to the thickness of the panels, since a block in the form of a pre-form for the panels is formed first, followed by slicing or cutting of the block into separate individual multiple panels

25 each having the required thickness of the panels, in a single molding operation

comprising a number of different workstations.

Two lower formers 72 are located at spaced apart locations on base 62 to provide support for channel section inserts 40 when placed in a substantially vertical orientation within mold 60 to form the lifting element. Formers 72 have a size, shape, 30 profile and cross-section corresponding to the size, shape and profile of access voids 52. Formers 72 can be lodged at any suitable location within mold 60 depending upon the desired position of the inserts.

Formers 72 are provided with U-shaped grooves 73 or cut-outs corresponding in shape, size and profile to the cross-section of inserts 40 so that the respective one ends 44 of inserts 40 can be received therein to securely retain inserts 40 in place prior to and during manufacture of panel 10. In one form, side walls 64, 66, in the form of side shields, are each provided with two slots 65 located at spaced apart locations at 5 the upper edge in use of each wall for locating upper formers as will be described later.

However, in other forms, slots 65 can be omitted entirely and replaced with clips or similar fittings for locating the upper formers, particularly to provide flexibility in locating the inserts.

A reinforcement mesh 74, in the form of a generally planar sheet of mesh or similar, or 10 a cage having a double layer of mesh in the form of two interconnected sheets of mesh is used to reinforce the panel. One form of mesh 74 comprises a multitude of lengthwise extending reinforcing rods 76 and a multitude of transversely extending reinforcing rods 78 interconnected in a grid or generally interconnected regular array is located within mold 60 to rest above base 62 and on lower formers 72 so as to provide i s a clearance between base 62 and the lowest part of mesh 74. It is to be noted that the number of sheets of mesh or cages of mesh, located in mold 60 corresponds to the number of panels being made from a single molding operation in mold 60. Accordingly the required number of sheets of substantially planar sheets of mesh 74, are located in spaced apart substantially parallel relationship inside mold 60 as shown more 20 particularly in Figure 14. Similarly, if reinforcement in the form of cages are used, the separate cages are located in spaced apart substantially parallel relationship to one another inside mold 60.

In one form, a sheet of suitable material, such as a membrane is located between the lower surface of lower former 72 and base 62 of mold 60 to seal around former 72 to 25 prevent the AAC mixture from gaining access internally within former 72, such as for example, by flowing around and underneath former 72. However, in other forms, the underside of the former can be manufactured from a suitable material to seal the underside of the former to the base of the mold thereby doing away with the need to have a separate membrane.

30 Inserts 40 are then located in place in grooves 73 to extend substantially vertically so that selected longitudinal rods 76 are located within the spaces of hooks 46 of insert 40 by tips 48 of the respective hooks 46 being forced open to allow movement of tips 48 of hooks 46 past rods 76 as shown in Figures 12a, 12b and 12c, to clip the insert to the selected rods collectively so as to retain inserts 40 in the substantially vertical orientation. It is to be noted that in one form, insert 40 has four spaced apart hooks 46 in which three hooks are located at or towards one end, being the lower end in use, when in the mold, and a single hook located at or towards the other end, being the 5 upper end in use, when the inserts are in the vertical orientation. After rod 76 passes tip 48 of hook 46, tip 48 is free to partially close by moving to resume the at rest position, thereby trapping rod 76 in the space between shank 41 of hook 46 and web 42 of insert 40.

When all of inserts 40 are secured in place within mold 60 and retained by hooks 46 10 engaging mesh rods 76 and being retained in grooves 43 of the pair of lower formers 72, one or more upper formers 80 are placed over the upper ends of inserts 40 collectively so as to sandwich each insert 40 between an upper former and lower former. Two upper formers 80 are generally used in alignment with the respective lower formers 72. In one form, upper former 80 is of a generally trapezoidal prism i s shape having a support pin 82 extending outwardly from each end and a multitude of U-shaped slots or grooves 84 located at spaced apart locations in the lengthwise extending direction. The position of grooves 84 correspond to the position of inserts 40. Support pins 82 are received in slots 65 of both side walls 64, 66 to assist in locating upper former 80 in place. The shape and/or profile of upper former 80, 20 corresponds to the shape and/or profile of access voids 52 located at spaced apart intervals along one longitudinal side of panel 10. Thus, lower formers 72 and upper formers 80 are of substantially the same profile and size. The shape of slots or grooves 84 correspond to the profile of inserts 40 so as to be received therein.

In one form, (not shown), upper former 80 is releasably secured to the upper edge of 25 side walls 64, 66 by a suitable fastener, such as for example, a clip, pin or similar to temporarily connect the ends of the upper former to the top of the side walls. This arrangement provides improved flexibility in locating the upper formers in the mold. In this form, slots 65 can be omitted.

When upper formers 80 are located in place with pins 82 received in slots 65 all of the 30 inserts 40 are collectively sandwiched between lower formers 72 and upper formers 80 so as to be securely retained in place both prior to and during formation of panel 10.

Similarly, when upper formers 80 are clipped or releasably fastened to the upper edge of side walls 64, 66, inserts 40 are sandwiched between the respective upper and lower formers, at any desired location.

Alternatively, in a different embodiment, upper former 80 can be replaced by a multitude of separate polystyrene blocks which are placed over the upper ends of each insert 40 and retained in place by an overhead gantry comprising a framework in the 5 form of a lattice and plates 94 provided with projections 96 located at spaced apart locations corresponding to the spacing a part of the ends of the inserts.

Gantry 86 is lowered to an extent that projections 96 are aligned immediately above each polystyrene block with projections 96 in register with the further transverse groove of the polystyrene block fitted over the end of the insert. Gantry 86 is further 10 lowered so that projections 96 are received in the further transverse slots of the

polystyrene blocks to retain the polystyrene blocks in position at the upper ends of each insert. In this position the inserts are sandwiched between lower formers 72 and the upper formers in the form of the polystyrene blocks which are retained in position by plates 94. i s A suitable fluid mixture for forming the AAC panels is introduced into mold 60 by a suitable delivery system to fill the chamber formed in mold 60. One form of delivery system is pneumatically or hydraulically conveying the fluid mixture. Other forms include a mechanical pump or the like. The fluid mixture flows over and around lower formers 72, mesh 74, inserts 40, and due to the composition of the mixture, expands

20 upwardly to flow up to and over upper formers 80 to completely fill the internal chamber of mold 60. It is to be noted that the profile of formers 72, 80 correspond to the shape of access voids 52 by each having a pair of tapering sides flanking a central straight section.

After molding, walls 64, 66, 68, 70 are displaced from mold 60 to reveal a block of 25 aerated concrete mix remaining in the mold chamber. Upper formers 80 and lower formers 72 are removed from the AAC block which is then cut longitudinally into separate panels 10 between the various sheets of mesh, such as for example, using a wire cutter or similar. Thereafter, each panel now of a nominal thickness

corresponding to the thickness of the finished panel, is allowed to cure, such as by air 30 drying and then autoclaved to form a rigid panel of AAC having the desired shape and dimensions with ends 44 of inserts 40 exposed in access voids 52. Optionally, the panels are trimmed to exact size. It is to be noted that the inserts do not extend beyond the width of the panels so that the long side of the panels can be trimmed without interference from the ends of the inserts. The fully cured panels are then stacked with ends 44 in alignment with each other ready for packaging, as shown in Figure 18. After packaging, the stack of aligned panels, are stored awaiting distribution when required.

5 After transportation and unpacking at a construction site, the panels can be lifted

simultaneously while remaining in stacked relationship by the movable grip or pin of a suitable lifting device engaging apertures 50 of the lifting elements of the lowermost panel.

The described arrangement has been advanced by explanation and many

10 modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the i s spirit and scope.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1 . A building panel comprising a body portion generally in the shape of the

building panel, the building panel having at least a first surface, the first surface being associated with at least a first lifting element for use in lifting the building panel, the lifting element having a first part for secure attachment of the lifting element to the body of the building panel in the region of the first surface to fixedly locate the lifting element with respect to the panel to facilitate lifting of the panel, the lifting element having a second part accessible from outside of the first surface of the building panel for cooperation with an external lifting device to lift the panel using the lifting device, wherein the second part of the at least first lifting element is provided with an engager for selective cooperative engagement with the lifting device such that when the lifting device is connected to the engager of the first lifting element, the panel moves in response to corresponding movement of the lifting device to move the panel.

A building panel according to claim 1 in the form of a lightweight building panel made from autoclaved aerated concrete in which the panel is in the shape of a substantially rectangular prism having two opposed faces, two opposed longitudinal sides and two opposed transverse ends.

3. A building panel according to any preceding claim in which the building panel is a reinforced building panel containing internal reinforcement, the reinforced building adapted for use in forming a floor of a building or for installation in forming a wall of a building.

4. A building panel according to any preceding claim further comprising one or more cooperative engaging elements located on one or more sides, edges or ends of the panel for interlockingly connecting two or more similar panels together by the cooperative engaging element of one building panel interlocking connecting with a complimentary engaging element of another building panel.

A building panel according to any preceding claim further comprising a first rebate located along a first side or edge and a second rebate located along a second side or edge in which the first rebate has a first shape or profile and the second rebate has a second shape or profile, the first rebate being different to the second rebate, the first rebate and the second rebate being adapted for receiving a locking member when to panels having the rebates are located in side by side relationship to one another, the locking member when received in the rebates for locking the building panels in position after installation of the panels in the building.

A building panel according to any preceding claim comprising a single lifting element, or two or more lifting elements in spaced apart relationship to each other, wherein the lifting element is a single insert or two or more inserts extending from one or more sides of the building panel.

A building panel according to any preceding claim in which the insert extends from one side of the building panel to the other side of the building panel such that both ends of the insert are exposed at either side of the building panel, the insert being a single insert extending from both opposite sides of the building panel or the insert being in two individual sections of the insert in which one end of each insert extends from one side of the panel wherein the two sections forming the insert are arranged collinearly with respect to each other or the two sections are located offset with respect to each other or are in staggered relationship with each other.

A building panel according to any preceding claim further comprising an access void in which the end of the insert is located in the access void.

A building panel according to any preceding claim in which the insert is a rod, bar, channel, grooved section having a generally U-shaped profile, a generally C-shaped profile or similar profile including having a central web section located between two spaced apart side walls or flanges extending from the web section at either side of the web section.

A building panel according to any preceding claim in which the insert further comprises an engager located at or towards the exposed end of the insert, the engager for engaging an operative part of a lifting device for use in lifting the building panel.

A building panel according to any preceding claim in which the engager is an aperture, opening, hole, bore, perforation, cavity, void or similar, or is a projection including a pin, peg, boss, spigot, rod, tube, stub, protrusion or the like.

12. A building panel according to any preceding claim further comprising at least one retainer for retaining the insert in position and orientation during manufacture of the panel, the retainer for cooperative engagement with

5 reinforcement incorporated in the building panel.

13. A building panel according to any preceding claim in which the reinforcement includes a reinforcement mesh in the form of a single sheet comprising an interconnected network of rods or bars located in spaced apart relationship to each other to form openings therebetween, or the reinforcement includes a

10 mesh cage made from two or more sheets or layers of networks of rods or bars located in spaced apart relationship to each other and interconnectedly joined together by spacers extending between the sheets or layers.

14. A building panel according to any preceding claim in which the retainer is a projection, protrusion or other outwardly extending fitting in the form of a metal i s hook, fastener, clamp, clip, barb, tongue, cleat, spike, tooth or similar having a shank portion and a tip portion.

15. A building panel according to any preceding claim in which the tip portion of the retainer is curved, the curved tip being resiliently deflectable or deformable so as to receive a reinforcement element and to cooperatively engage the

20 reinforcement element to retain the insert in position.

16. A building panel according to any preceding claim in which the spacing apart of the retainer on the insert corresponds to the spacing apart of the individual reinforcing elements of the reinforcement.

17. A building panel according to any preceding claim in which the exposed end of 25 the insert is inclined so as to be tapered, bevelled, angled or similar, or the exposed end of the insert is straight, being substantially perpendicular to the lengthwise extending axis of the insert.

18. A building panel according to any preceding claim comprising a multitude of individual inserts, the inserts being arranged in substantially parallel spaced

30 apart relationship to one another to extend from one longitudinal side to the other longitudinal side in substantially parallel relationship to the opposed ends of the panel extending between the two longitudinal sides of the panel, wherein the exposed ends of the inserts are located within respective voids and provided at spaced apart locations along the longitudinal sides of the panel, the spacing apart of the voids corresponding to the spacing apart of the inserts to provide access to the ends of the inserts.

A building panel according to any preceding claim in which the access void is provided with inclined sides, wherein the sides diverge outwardly in the direction to the edge of the longitudinal side of the panel in which the access void is located, the outwardly directed diverging sides being tapered, bevelled or similar to provide clearance for access to the end of the insert for cooperative engagement of the engager by the lifting device.

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