AU2004100393B4 - Building panel - Google Patents

Description

25/05/2064 15:33 +613-9890-1337 PATENT ATTORNEY SERV PAGE 06/18 BUILDING PANEL FIELD OF THE INNOVATION This innovation relates to improvements in building panels for use in construction of walls and similar structural elements such as floors in reinforced concrete.

BACKGROUND

A known method for construction of reinforced concrete walls and similar building elements relies on the use of factory-fabricated panels having facing sheets and therebetween a linear array of spacer members that are parallel to each other- In the case of an upright wall, the spacer members arm in effect studs, extending vertically. After placement of suitable reinforcement between the facing sheets, concrete is poured into cavities defiued between the facing sheets ard the spacer members to complete the building element. Openings are provided in the spacer members through which reinforcing members are passed. When the concrete is poured, the openings also provide fluid communication between pairs of adjacent cavities so that there is formed a continuous reinforced concrete mass. This method of construction can in suitable applications provide significant advantages in speed and ease of construction, and so reduce costs. The facing sheets may be of fire-resistant materials.

In one panel of this type proposed in the past (but not admitted to be common general knowledge), the facing sheets at one or both ends overhang the endmost spacer members. When such panels of this type are used in edge-to-edge manner, the facing sheets of adjacent panels are placed edge to edge so that a further cavity is defined between the two pairs of opposing facing sheets and the spaced-apart endmost spacer members of each panel. Concrete is placed in that cavity along with the cavities in the panels themselves.

A problem that has been encountered with this arrangement is a degree of splaying or bulging outward of the abutting facing sheet edges otadjacent panels following pouring of the concrete, leading to a departm from the desired flat wall surface at the joint position. Apart from aesthetic considerations, such a bulge can create problems with later finishing, cladding, lining and similar processes. Rectifying this problem may be difficult and expensive.

The present innovation addresses this problem, Moreover the preferred embodiment of innovation is believed to provide an additional structural benefit in increased resistance of the completed wall to in-plane shear loads.

I

COMS ID No: SBMI-00764493 Received by IP Australia: Time 15:45 Date 2004-05-25 12/03/2008 11:38 12/3/0091139 61-3-9901337 PATENT ATTORNEY SERV PG 36 PAGE 03/06 00 0 SUMMARY OF THE INNOVATION According to the innovation there is provided a building panel for use in construction of walls and thc like, the panel including first and second facing sheets spaced apart from each other and a plurality of elongate spacer members between the facing sheets, wherein: the first and second facing sheets arc respectively secured to opposite sides of o each said spacer member; 010 a said spacer member includes a web that extends in a plane between the facing o sheets and that has openings therein spaced apart along its length. to permit flow of o concrete through the web; and said web has at least one web stiffening formation projecting therefrom to at least partially surround one of said openings, the formation having a component of its projection extending transverse to the plane of the web so as to increase resistance of the web to deformation about an axis extending in the plane of the web and having a component of its projection extending parallel to the plane of the web so as to increase resistance of the web to deformation about an axis extending transverse to the plane of the web.

It is believed that where edges of the facing sheets overhang an endmost spacer member, undesired splaying outward or bulging of facing sheet edges is associated with a lack of rigidity of the spacing members, in addition to thc effect of hydrostatic pressure in the wet concrete, -so that stiffening the spacing members in. an appropriate manner can help alleviate the problem. Providing transverse stiffening formations only, such as linear transverse deformations of the web, can stiffen the spacing members against deformation of the web associated with bulging of the facig sheet edges, but such formations may lead to a different undesirable effect of bowing of the spacer member about transverse axis along the length of the spacer member. Hence each of the web stiffening formations has also been provided with a component of its length in. the longitudinal direction to resist such bowing.

Preferably, the web is formed of sheet material and the formnation includes a part of the web so deformed as to be laterally displaced fr-om the general plane of the web 2 COMS ID No: ARCS-182634 Received by IP Australia: Time 12:36 Date 2008-03-12 25/05/2004 15:33 -I613-9890-1337 PTN TE\E EVPG 81 PATENT ATTORNEY SERV PAGE 08/18 adjacent to the formation. This is a particularly convenient way to provide stiffening of a web that is fanned from sheet metal, It is particularly preferred that a said formation includes a raised lip exending entirely around and defining a periphery of the opening. Again, this arrangement is convenient in the case of a formed sheet metal spacer member.

In addition, it is taought that deformations out of the general plane of the web, including peripheral lips are particularly effective in improving the resistance of walls constructed in the maimer disclosed above to in-plane horizontal and vertical shear loads, In a preferred emnbodiment of the innovation, eah spacer member is of generally C-shaped or Z-shaped cross-section having flanges that are secured to the Lacing sheets, the web extends between the flanges and each of the openings has a closed continuously curved peripheral shape (preferably circular, but possibly elliptical edo). The innovation is suitable for use in the construction of fire-resistant building elements. At least one of the theig sheets may be formed of a fire resistant material.

In a tbrher aspect, the innovation provides a building element constructed using two (or more) building panels in any of the forms disclosed above, the panels being stood edge to edge so that the spacer members extend substantially vertically and with concrete placed in at least the cavity defined by the panels between the spacer members nearest their respective adjoining edges.

In order that the innovation may be better understood, it will now be described noni-limitingly by reference to preferred embodiments as shown in the attached Figures, of which: Figure I is a partial plan view from above of a prior art building panel; Figure 2 is a side elevation of the prior art building panel shown in Figure 1; Figure 3 is an end elevation of the panel shown in Figure 2, looking in the direction of arrow in Figure 2; Figure 4 is a plan view from above of part of a wall formed from building panels of the type shown in Figure 1; Figure 5 is an end view of part of a building panel according to the innovation; Figure 6 is a partial plan view from above of the building panel shown in Figure 3 OOMS ID No: SBMI-00764493 Received by IP Australia: Time 15:45 Date 2004-05-25 25/85/2004 15:33 +613-9890-1337 PTN TObY5WPG 91 PATENT ATTORNEY SERV PACE 09/18 Figure 7 is a partial cross-sectional view of two PanelIs of the kind shown in Figure 5, the section being taken at section ".B-B31 in Figure 5, abutted edge to edge with concrete infill to form a building element.

DETAILED DESCRIPTION OF PREFERRED

EMBODIM&ENT

Figuires 1 3 show part Of a rectangular building panel1 I of a known type (hut not admitted to be common general knowledge). Panel 1 includes two facing sheets 2 spaced apart and parallel to each other. Secured to and located between facing sheets 2 are elongate spacer members 3. Members 3 are parallel to each other, spaced apart, and extend between ant upper edge 4 and a lower edge (not shown) of the panel 1. Cavities are defined between adjacent pairs of spac~er members 3 and opposing facing sheets 2.

Several rectangular openings 6 are provided in each of the spacers 3 and are spaced apart therealong.

For use in Conning faced concrete walls, the spacer members 3 are metal (e.g.

galvanized steel) channel-sections. Spacer members 3 are bonded to facing sheets 2, which may be of any sheet material suitable for te intended application. Facing sheets 2 may for example be fire-resistant material such as fibre cement sheet. flanges 8 of the spacer members 3 abut the facing sheets and webs 7 extend transversely therebetween.

To illustrate a use of panel 1, Figure 4 shows part of a faced concrete wall constricted using two such panels, la and lb. (In the following text, item numbers with suffices "a"and indicate parts of panels la and l b and are otherwise as used above.) The part of wall 10 that is shown includes ajoint between adjacent panels la and lb.

Panels la and lb are located side by side, with each facing sheet 2a of panel la abutting a corresponding facing sheet 2b of panel I b, so that a cavity Ill s defined by spacer members 3a and 3b and facing sheets 2a and 2b. Reinforcement 12 is positioned centrally between the 6cing sheets 2a and 2b. Reinforcement 12 is shown schematically only in Figure 4, and typically consists of horizontal rods extending through the openings 6 of panels Ina and I b and vertical rods extending vertically through the cavities 5a, 5b and 11.

After placement of the panels la and lb and of the reinforcement 12, concrete l3 is poured into at lest one of the cavities 5a, 5b and I I and allowed to set to complete wall 10. Concrete 13 can flow through openings 6a and 6b during the pouring process. This has important structural significance in many cases, as disclosed later herein.

Edge regions 14 of facing sheets 2a, and 2b are butted together and experience a degree outward force (in 'the directions of arrows 15) under the hydrostatic pressure of 4 COMS ID No: SBMI-00764493 Received by IP Australia: Time 15:45 Date 2004-05-25 25/05/2004 15:33 +613-9890-1337 PTN TO~E EYPG 01 PATENT ATTORNEY SERV PAGE 10/18 the concrete 13 in cavity II.- As a result there can be some outward movement of dhe edges 14 providing a bulge or waviness in facing sheets 2, and this is undesirable.

Rernediation may be difficult and costly and, where facing sheets 2 are chosen for special properties such as fire resistance those properties may be compromised if remediation involves reductions of bulge's thickness of facing sheets 2.

Referring now to Figures 5 there is shown a building panel 21 that accords with the present innovation and alleviates the problem mentioned in the previous paragraph. Panel 21 is generally simailar to panel 1 having facing sheets 22 separated by and bonded to an array of spacer members 23 that are elongate and parallel to each other and that with sheets 22 define internal cavities 25. Each of the spacer members 23 has a channel-shaped cross-section having a web 27 and having outer flanges 28 to which the sheets 22 are bonded. Openings 26 are spaced apart along the web 27 and correspond to openings G in webs 7 of panel 1. The openings 26 are circular. However, panel 21, differs from panel I in that each opening 26 has a lip 29 formed around its periphery.

Lips 29 have the effect of stiffening the webs 27. The lips 29 have the effect of reducing the bulging effect mentioned above. Without in any way being restricted to any particular explanation of this result, it is thought that the lips 29 limit the tendency of the web 27 of a spacer 23 to defonn about an axis extending along the length of the space 23, i.e. distort into a curved shape when seen irt cross-section (as in Figures 6 and 7) so that flanges 28 of' the spacer members 23 cease to be parallel to each other, along with bonded facing sheets 22 in the vicinity of those flanges.

In the preferred embodint of panel 2 1, spacer members 23 are cold-formed from sheet steel, the openings 26 being punched out in known manner. In this case, lips 29 can conveniently be formed integrally with spacer members 23, in one or several, 2$ stamping steps following the punching operation or in a single operation with the punching of openings 26. The precise choice of the process will depend on the metallurgical composition and history of the steel, its gauge and the extent of raising of the tips 29 from the plane of the webs 27 found to be required to achieve satisfactory performane. These factors relate only to execution of the innovation and are part of the established art of producing such sections.

Of course, openings with stiffening lips may be provided by other means, for example by punching out openings corresponding to openings 26 without forming COMS ID No: SBMI-00764493 Received by IP Australia: Time 15:46 Date 2004-05-25 25/05/2004 15:33 +613-9890-1337 PTN TO~E EVPG 11 PATENT ATTORNEY SERV PAGE 11/18 integral lips and instead welding rings .(not shown) around the peripheries of those openings.

Peripheral stiffening lips 29 in particular mnay have the important additional advantage of improving the resistance of walls constructed in the manmer disclosed above to in-plane horizontal and vertical shear loads. Resistance to such loads depends substantially on integrity of the concrete witn the openings 6 or 26. In both cases, a particular failure mode involves rupture of the concret within the openings 6 0or 26 so that the concrete in each cavity 5 or 25 tends to slip along spacer members 3 or resisted by the concrete reinforcement (eg reinforcement 12). The present innovation in effect provides improved transfer of shear stresses between opposite sides of the spacer members additional to that provided by the concrete (and reinfforcement) in the openings 26. In particular, it is believed that lips 29 provide an especially effective way to improve transfer of shear stresses between opposite sides of the spacer members 23.

Panels 21 tan be used in applications other than the construction of walls e.g. can be used in concrete floor construction.

All of the above description has been based on building panels 21 that are rectangular, thAt have parallel facing sheets 22 and spacer members 23 that are parallel and of a particular setion. Such panels are of the g rst importance in practice.

However, it is to be understood that panels of other shapes, with other arrangements of spacer members are subject to the same principles and the present innovation can apply also to them. The scope of the present innovation is set out in the appended claims.

6 COMS ID No: SBMI-00764493 Received by IP Australia: Time 15:45 Date 2004-05-25

Claims (3)

1. 2. A building panel according to claim 1 wherein said web is formed of sheet material and said formation includes a part of said web so deformed as, to be laterally displaced from the general plane of said web adjacent to the -Formation.
2. 3. A building panel according to claim 1 or 2 wherein a said formation includes a raised lip extending entirely around and defining a periphery of a respective one of said openings.
3. 4. A building panel, according to any one of claims I to 3 wherein said at least one spacer member has a cross-section including flanges that are secured to said facing sheets 7 COMS IDNo: ARCS-182634 Received by IP Australia: Time 12:36 Date 2008-03-12 25/05/2004 15:33 +613-9890-1337PAET TTbYSRVAG 1/1 PATENT ATTORNEY SERV PAGE 13/18 wherein said web extends between said flanges, and wherein each of said openings has a closed continuously curved peripheral shape. A building element constructed using two building panels according to any one of claims I to 4 said panels being stood edge to edge so that said spacer members extend substantially vertically and with concrete placed in at least the cavity defined. by said panels between the spacer members nearest their respective adjoining edges. Dated this 25t' day of' May 2004 PATENT ATTORNEY SERVICES Attorneys for GORDON MALCOLM STEVENS and VALERIE FRANCES STEVENS COMS 10 No: SBMI-00764493 Received by IP Australia: Time 15:45 Date 2004O05-25